Early detection of acute mountain sickness after high-altitude exposure

Early detection of acute mountain sickness after high-altitude exposure | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Early detection of acute mountain sickness after high-altitude exposure Yun Xu, Sijia Wang, Yong Jing, Qingfeng Zhang, Kai Wang, Yan Deng, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8777421/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 10 You are reading this latest preprint version Abstract BACKGROUND Early identification of individuals vulnerable to acute mountain sickness (AMS) is clinically challenging. We hypothesized that exercise stress echocardiography (ESE), conducted shortly after high-altitude arrival, could reveal distinctive right ventricular (RV) and pulmonary vascular responses predictive of AMS development. METHODS Within 6 hours of arrival, 50 healthy lowland residents underwent ESE. Key measures included systolic pulmonary artery pressure (SPAP), pulmonary vascular resistance (PVR), tricuspid annular peak systolic velocity (TV s′), RV fractional area change (FAC), inferior vena cava (IVC) diameter, and mean PAP/cardiac output (CO) slope. AMS was assessed the next morning using the Lake Louise Score. RESULTS Of the participants, 23 (46%) developed AMS and 27 (54%) did not (non-AMS group). At peak exercise, the AMS group exhibited significantly higher SPAP (54.88 ± 7.89 vs. 46.71 ± 8.48 mmHg, p < 0.001) and PVR (2.24 ± 0.26 vs. 2.03 ± 0.17 WU, p = 0.001), accompanied by greater increases from rest (denoted as Δ) in SPAP (20.42 ± 8.13 vs. 13.21 ± 6.22 mmHg, p = 0.015) and PVR (0.40 ± 0.19 vs. 0.30 ± 0.17 WU, p = 0.010). Conversely, the AMS group demonstrated impaired RV contractile reserve, reflected by smaller in ΔTV s′ (0.05 ± 0.04 vs. 0.08 ± 0.03 m/s, p = 0.006) and ΔFAC (8.26 ± 3.89 vs. 12.22 ± 5.35%, p = 0.033). IVC diameter was larger in the AMS group both at rest and during peak exercise (p = 0.047 and p = 0.018). A nomogram incorporating peak IVC diameter, ΔPVR, and ΔTV s′ predicted AMS with an area under the curve (AUC) of 0.865 and an accuracy of 84.0%. CONCLUSION ESE detects early alterations in RV function, IVC dynamics, and pulmonary circulation in individuals susceptible to AMS within hours of high-altitude exposure. A model based on IVC, ΔPVR, and ΔTV s′ offers a practical tool for early AMS risk stratification. Clinical trial number: not applicable Acute Mountain Sickness RV Function Pulmonary Artery Pressure Pulmonary Vascular Resistance Exercise Stress Echocardiography Figures Figure 1 Figure 2 Figure 3 Introduction Acute mountain sickness (AMS), the most common acute high-altitude illness, typically affects individuals who ascend rapidly to elevations above 2,500 meters without adequate acclimatization. Its incidence ranges from 25% to 85% within the 2,500–4,500 meter altitude range [ 1 ] . AMS is characterized by symptoms such as headache, dizziness, gastrointestinal disturbances, and fatigue, which usually begin within hours of high-altitude exposure and peak in severity on the first night. In severe cases, AMS can progress to life-threatening complications, including high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE) [ 2 ] . Although the cardiovascular system does not directly sense changes in ambient oxygen partial pressure, its compensatory responses, particularly those of the right ventricular (RV)-pulmonary circulation unit, are crucial for systemic adaptation to hypoxia [ 3 ] . At rest, studies have shown that AMS patients exhibit RV and pulmonary circulatory function comparable to the non-AMS group both at low altitude and high-altitude exposure [ 4 – 6 ] . Exercise stress testing is well established as a sensitive method for detecting latent changes in pulmonary circulation and RV function [ 7 , 8 ] . Our previous research during peak exercise at low altitude demonstrated that although AMS-susceptible individuals maintain RV function and contractile reserve similar to non-AMS subjects, they exhibit elevated pulmonary arterial pressure (PAP), increased pulmonary vascular resistance (PVR), larger inferior vena cava (IVC) diameter, and higher B-line counts after exercise. These parameters significantly predict subsequent AMS development [ 4 ] . Notably, no study has yet comprehensively characterized the RV-pulmonary circulation unit in AMS-susceptible individuals during exercise following high-altitude exposure. To address this gap, we hypothesized that exercise stress echocardiography (ESE) can detect differences in RV-pulmonary circulatory responses between AMS and non-AMS subjects within the first few hours at moderate high altitude. This study aimed to evaluate these differential responses and assess their predictive validity for AMS occurrence. The noninvasive identification of an AMS-vulnerable phenotype could provide a theoretical basis for guiding decisions regarding continued high-altitude exposure and further ascent. METHODS Study Setting and Ethics This prospective cohort study was conducted in Xinduqiao Town, Kangding, Sichuan Province, China, at an average altitude of 3,600 meters. The study protocol received approval from the Institutional Research and Ethical Committees of Sichuan Provincial People′s Hospital (Approval No. 2023 − 436) and adhered to the Declaration of Helsinki. Written informed consent was obtained from all participants prior to any study procedures. Study Population Fifty-seven healthy low-altitude residents were initially enrolled. Exclusion criteria included: known cardiovascular disease, ongoing cardiovascular treatments, multiple exposures to altitudes above 2,500 meters within the previous six months, history of severe mountain sickness, angioedema, pregnancy, fertile women not using effective contraception, and professional athletes. All participants underwent comprehensive health screening before inclusion. After initial recruitment, seven subjects were excluded: two developed significant headaches upon arrival and did not undergo stress echocardiography for safety reasons; four had inadequate tricuspid regurgitation Doppler images (one at rest, three at peak exercise); and one declined participation. The final analysis included 50 participants (31 males, 19 females; mean age 35 ± 7 years) (Fig. 1 ). Study Protocol Participants ascended by bus over 24 hours, with an overnight rest at 2,150 meters before reaching the final altitude of 3,600 meters. Following arrival, participants rested for 3 hours before undergoing supine bicycle ESE within the first 6 hours of high-altitude exposure. Oxygenation and general health status were continuously monitored throughout. On the morning following arrival, participants completed the 2018 Lake Louise Score (LLS) questionnaire [ 9 ] . AMS was defined as a total score ≥ 3 points, including at least one point for headache. Participants with scores < 3 were classified as non-AMS (Fig. 2 ). ESE Exercise testing was performed using a semi-recumbent cycle ergometer (Ergoselect II 1200; Ergoline, Bitz, Germany). Standard transthoracic echocardiography was conducted at rest and during exercise using a commercial ultrasound system (Vivid E95, GE Vingmed Ultrasound) with a 3.5-MHz M5S transducer. The exercise protocol consisted of incremental cycling at 60 revolutions per minute, beginning with a 2-minute unloaded phase followed by stepwise increases of 25 W every 2 minutes until volitional exhaustion. Participants' oxygenation, blood pressure, heart rate (HR), and electrocardiogram were continuously monitored throughout the procedure. All image acquisitions followed standardized protocols [ 10 ] and were performed by the same physician. Echocardiographic Analysis All echocardiographic parameters were measured offline according to current guidelines of the American Society of Echocardiography and the European Association of Cardiovascular Imaging, including the specific recommendations for stress echocardiography [ 11 , 12 ] . Image analysis was performed offline using Echo PAC software (version 204, General Electric Vingmed Ultrasound) Comprehensive assessment included: Left ventricular ejection fraction (LVEF) using biplane Simpson′s method, Cardiac output (CO) derived from left ventricular outflow tract diameter, time velocity integral, and heart rate, RV fractional area change (FAC), Tricuspid regurgitation velocity (TRV) using continuous-wave Doppler, Tricuspid annular peak systolic velocity (TV s′) using tissue Doppler, Pulmonary artery systolic pressure (SPAP) estimated from TRV and right atrial pressure, Mean pulmonary artery pressure (mPAP) calculated as 0.6 × SPAP + 2 mmHg [ 13 ] , Pulmonary vascular resistance (PVR) estimated using the formula: (mPAP - PAWP)/CO, with pulmonary artery wedge pressure (PAWP) estimated from E/e′ ratio [ 14 ] , Tricuspid annular plane systolic excursion (TAPSE), RV-pulmonary artery coupling indices (TAPSE/SPAP, TV s′/SPAP) and mPAP/CO relationship. Automated functional imaging was employed to assess RV longitudinal strain (LS), with manual adjustment of the region of interest as needed to ensure accurate wall tracking. Strain analysis included the following specific parameters: right ventricular global longitudinal strain (RVGLS), free wall longitudinal strain (FWLS) with its segments—free wall basal segment longitudinal strain (FWLS-base), free wall mid segment longitudinal strain (FWLS-mid), and free wall apical segment longitudinal strain (FWLS-apex)—as well as interventricular septal longitudinal strain segments comprising interventricular septal basal segment longitudinal strain (IVSLS-base), interventricular septal mid segment longitudinal strain (IVSLS-mid), and interventricular septal apical segment longitudinal strain (IVSLS-apex).Lung ultrasound was performed using a simplified 2-site scan (third intercostal space, from mid-axillary to anterior axillary line bilaterally), with abnormal response defined as ≥ 1 B-lines [ 15 ] .Functional reserve parameters (Δ) were calculated as the difference between peak exercise and resting values for FAC, TAPSE, TV s′, SPAP, mPAP, PVR, and B-lines. Statistical Analysis All statistical analyses were performed using SPSS (version 26.0; IBM Corp.) and R (version 3.6.1). Categorical variables are presented as numbers and percentages and were compared using the chi-square test. Continuous variables were tested for normality using the Shapiro–Wilk test. Normally distributed variables are expressed as mean ± standard deviation and compared using the independent-samples t-test, while non-normally distributed variables are summarized as median with interquartile range and compared using the Mann–Whitney U test. To identify independent predictors of AMS, multivariable logistic regression analysis with stepwise selection (both forward and backward) was performed. Variables showing a significant univariable association with AMS (P < 0.05) were included as candidates in the initial model. Variable entry and retention were based on a significance level of P < 0.05, and removal was set at P ≥ 0.10. The performance of the final model was comprehensively evaluated using R software. A nomogram was constructed based on the regression coefficients to visualize the individualized prediction of AMS risk. Model calibration was assessed using a calibration curve with 1,000 bootstrap resamples, along with the calibration intercept and slope. Discriminatory ability was measured by the area under the receiver operating characteristic curve (AUC), which was plotted using the pROC package. Decision curve analysis (DCA) was performed to evaluate the clinical net benefit across a range of threshold probabilities. Finally, clinical impact curves (CIC) were plotted to illustrate the actual number of high-risk individuals identified versus the number of true events at different risk thresholds, providing quantitative guidance for clinical decision-making. Results Incidence of AMS and Clinical Characteristics At 3,600 m, 23 of the 50 subjects (46%) were diagnosed with AMS (AMS group), while the remaining 27 (54%) comprised the non-AMS group. Among all participants, headache was reported by 35 individuals (70%), gastrointestinal symptoms by 8 (16%), fatigue and/or weakness by 26 (52%), and dizziness or light-headedness by 22 (44%) (Table 1 ). No statistically significant differences were observed between the two groups in baseline characteristics, including sex distribution, age, body surface area, body mass index, heart rate, blood pressure, or oxygen saturation (all p > 0.05) (Table 2 ). Table 1 Distribution and Incidence rates of AMS-related symptoms (50 subjects) Symptom 0 points 1 point 2 points 3 points incidence Headache 12 21 14 3 0.70 Gastrointestinal symptoms 42 7 1 0 0.16 Fatigue and/or weakness 24 18 8 0 0.52 Dizziness/light-headedness 28 16 6 0 0.44 Table 2 Baseline characteristics and resting echocardiographic parameters at 3600 m.. REST all non-AMS N = 27 AMS N = 23 t/z/χ² P Basic characteristics Sex, male (%) 34(68%) 16(59%) 18(78%) χ²=2.10 0.147 Age, yrs 39 ± 8 39 ± 7 40 ± 7 t=-0.574 0.569 Smoking, n (%) 11(22%) 4(15%) 7(30%) χ²=1.750 0.186 BSA (m 2 ) 1.73 ± 0.19 1.72 ± 0.21 1.74 ± 0.18 t=-0.158 0.875 BMI (kg/m 2 ) 22.96 ± 3.45 23.06 ± 3.62 20.82 ± 3.29 t = 0.233 0.816 HR, b/m 93.14 ± 11.54 92.30 ± 11.18 94.13 ± 12.13 t=-0.556 0.581 SBP, mmHg 123.96 ± 12.92 123.11 ± 14.74 124.96 ± 10.64 t=-0.499 0.620 DBP, mmHg 81.60 ± 12.24 79.78 ± 14.30 83.74 ± 9.12 t=-1.144 0.258 SpO2, % 84.42 ± 4.23 84.26 ± 4.33 84.61 ± 4.20 t=-0.288 0.774 Right heart and pulmonary circulation parameters TRV, m/s 2.72 ± 0.34 2.66 ± 0.35 2.79 ± 0.31 t=-1.332 0.189 TV s′,cm/s 0.14 ± 0.02 0.14 ± 0.02 0.15 ± 0.02 t=-1.579 0.135 TV e′,cm/s 0.16 ± 0.04 0.15 ± 0.05 0.16 ± 0.04 t=-0.470 0.641 TV a′,cm/s 0.17 ± 0.05 0.17 ± 0.05 0.18 ± 0.05 t = 1.017 0.314 TAPSE, mm 20.90 ± 2.93 20.52 ± 2.71 21.35 ± 3.17 t=-0.998 0.323 SPAP, mmHg 33.08 ± 7.42 31.86 ± 7.53 34.51 ± 7.19 t=-1.267 0.211 mPAP, mmHg 19.86 ± 4.45 19.14 ± 4.52 20.71 ± 4.32 t=-1.246 0.219 PVR, WU 1.81 ± 0.20 1.79 ± 0.18 1.83 ± 0.24 t=-0.606 0.548 RVD1, mm 31.44 ± 4.16 30.96 ± 4.13 32.00 ± 4.22 t=-0.876 0.385 RVD2, mm 30.52 ± 4.07 30.15 ± 3.42 30.96 ± 4.77 t=-0.696 0.490 RVD3, mm 51.80 ± 5.21 52.41 ± 5.63 51.09 ± 4.70 t = 0.891 0.378 FAC, % 44.80 ± 5.89 44.82 ± 6.20 44.78 ± 5.62 t = 0.983 0.443 TV s′/SPAP ratio 0.42 ± 0.11 0.42 ± 0.10 0.44 ± 0.11 t=-0.738 0.464 TAPSE/SPAP, mm/mmHg 0.66 ± 0.15 0.67 ± 0.16 0.64 ± 0.15 t = 0.681 0.499 IVC, mm 10.38 ± 3.06 9.59 ± 2.79 11.30 ± 3.15 t=-2.036 0.047 RVGLS, % 21.53 ± 2.99 21.47 ± 2.62 21.60 ± 3.43 t=-0.162 0.872 FWLS, % 25.41 ± 4.77 25.79 ± 4.90 24.97 ± 4.67 t = 0.604 0.549 FWLS-base, % 34.33 ± 8.52 33.36 ± 9.43 35.48 ± 7.37 t=-0.874 0.386 FWLS-mid, % 27.22 ± 8.77 26.85 ± 8.79 27.65 ± 8.92 t=-0.319 0.751 FWLS-apex, % 22.00 (17.25, 26.00) 22.00 (18.00, 26.00) 22.00 (16.50, 27.00) Z=-0.039 0.969 IVSLS-base, % 22.62 ± 7.54 22.14 ± 6.32 23.17 ± 8.88 t=-0.479 0.634 IVSLS-mid, % 18.69 ± 5.04 17.46 ± 5.43 20.13 ± 4.20 t=-1.921 0.061 IVSLS-apex, % 15.21 ± 4.98 16.39 ± 5.33 13.83 ± 4.23 t = 1.860 0.069 Left heart parameters E (cm/s) 0.73 ± 0.15 0.76 ± 0.14 0.70 ± 0.16 t = 1.331 0.190 A (cm/s) 0.72 ± 0.20 0.75 ± 0.21 0.69 ± 0.20 t = 1.040 0.304 MV e′,cm/s 0.15 ± 0.03 0.14 ± 0.03 0.15 ± 0.03 t=-0.141 0.889 MV a′,cm/s 0.10 ± 0.03 0.10 ± 0.03 0.11 ± 0.03 t=-1.035 0.306 E/e′ ratio 6.28 ± 1.47 6.42 ± 1.30 6.13 ± 1.65 t = 0.689 0.494 LVEF, % 64.00 ± 3.53 64.59 ± 3.09 63.30 ± 3.94 t = 1.296 0.201 CO, L/min 4.24 ± 0.33 4.20 ± 0.31 4.29 ± 0.36 t=-0.980 0.332 AMS, acute mountain sickness; BMI, body mass index; BSA, body surface area; DBP, diastolic blood pressure; HR, heart rate; SBP, systolic blood pressure; SpO₂, oxygen saturation; CO, cardiac output; FAC, fractional area change; IVC, inferior vena cava; LVEF, left ventricular ejection fraction; mPAP, mean pulmonary arterial pressure; PVR, pulmonary vascular resistance; RVD1/2/3, right ventricular basal/mid-cavity/longitudinal diameter; SPAP, systolic pulmonary arterial pressure; TAPSE, tricuspid annular plane systolic excursion; TRV, tricuspid regurgitation velocity; TV s′/e′/a′, tricuspid annular peak systolic/early diastolic/late diastolic velocity. Exercise Stress Echocardiography Findings At rest, no significant differences were observed between the AMS and non-AMS groups in key echocardiographic parameters, including SPAP, mPAP, TV s′, and FAC (all p > 0.05), except for IVC diameter, which was significantly smaller in the non-AMS group (p = 0.047) (Table 2 ). At peak exercise, although exercise duration (p = 0.062) and peak heart rate (p = 0.682) were comparable between groups, the AMS group achieved a significantly lower workload (p = 0.015). No significant intergroup differences were observed in heart rate, systolic/diastolic blood pressure, oxygen saturation, TAPSE, FAC, RV global and regional longitudinal strain parameters, or left heart parameters including E, A, E/e′ ratio, LVEF, and CO (all p > 0.05). In contrast, the AMS group demonstrated a markedly exaggerated pulmonary vascular response, characterized by significantly higher values in TRV (p = 0.001), SPAP (p < 0.001), mPAP (p < 0.001), PVR (p = 0.001), IVC diameter (p = 0.018), and mPAP/CO slope (p = 0.022), along with a greater number of subjects exhibiting B-lines (≥ 1) during ESE (p = 0.035). Conversely, the TV s′/SPAP ratio (p = 0.003) and TAPSE/SPAP ratio (p = 0.017) were significantly lower in the AMS group (Table 3 ). Table 3 Exercise testing results and measures at 3600 m. PEAK all non-AMS N = 27 AMS N = 23 t/z/χ² P Basic characteristics HR, b/m 144.08 ± 13.83 143.33 ± 13.71 144.96 ± 14.22 t=-0.412 0.682 SBP, mmHg 160.87 ± 21.05 159.98 ± 23.21 161.91 ± 18.64 t=-0.320 0.750 DBP, mmHg 89.86 ± 14.45 90.23 ± 17.41 89.43 ± 10.30 t = 0.199 0.843 SpO2, % 82.21 ± 6.08 83.06 ± 6.90 81.39 ± 5.11 t=-0.197 0.845 Exercise duration (min) 6.96 ± 1.96 7.30 ± 1.35 6.57 ± 1.34 t = 1.911 0.062 Load (Watt) 106.00 ± 19.27 112.04 ± 18.82 98.91 ± 17.64 t = 2.529 0.015 Right heart and pulmonary circulation parameters TRV, m/s 3.43 ± 0.33 3.30 ± 0.32 3.59 ± 0.28 t=-3.479 0.001 TV s′,cm/s 0.21 ± 0.03 0.21 ± 0.03 0.20 ± 0.04 t = 1.761 0.085 TV e′,cm/s 0.21 ± 0.06 0.20 ± 0.06 0.22 ± 0.06 t=-1.077 0.287 TV a′,cm/s 0.25 ± 0.07 0.25 ± 0.07 0.24 ± 0.07 t = 0.586 0.561 TAPSE, mm 26.69 ± 3.08 26.24 ± 2.66 27.22 ± 3.49 t=-1.125 0.266 SPAP, mmHg 50.47 ± 9.11 46.71 ± 8.48 54.88 ± 7.89 t=-3.506 < 0.001 mPAP, mmHg 30.28 ± 5.46 28.03 ± 5.09 32.93 ± 4.73 t=-3.506 < 0.001 PVR, WU 2.13 ± 0.24 2.03 ± 0.17 2.24 ± 0.26 t=-3.450 0.001 RVD1, mm 32.38 ± 4.28 31.34 ± 3.14 33.61 ± 5.12 t=-1.851 0.073 RVD2, mm 31.16 ± 4.59 30.41 ± 2.63 32.04 ± 6.09 t=-1.196 0.241 RVD3, mm 52.40 ± 5.25 52.30 ± 4.95 52.52 ± 5.69 t=-0.147 0.883 FAC, % 55.66 ± 5.89 57.03 ± 5.95 54.04 ± 5.51 t = 1.834 0.073 TV s′/SPAP ratio 0.41 ± 0.10 0.45 ± 0.10 0.36 ± 0.09 t = 3.138 0.003 TAPSE/SPAP, mm/mmHg 0.54 ± 0.10 0.58 ± 0.09 0.51 ± 0.10 t = 2.477 0.017 IVC, mm 13.74 ± 3.15 12.78 ± 2.50 14.87 ± 3.51 t=-2.454 0.018 RVGLS, % 23.41 ± 3.89 23.91 ± 4.17 22.81 ± 3.54 t = 0.998 0.323 FWLS, % 25.64 ± 6.98 26.98 ± 7.48 24.07 ± 6.12 t = 1.484 0.144 FWLS-base, % 40.11 ± 9.74 42.12 ± 10.24 37.75 ± 8.76 t = 1.606 0.115 FWLS-mid, % 25.88 ± 9.44 25.34 ± 9.05 26.52 ± 10.03 t=-0.439 0.663 FWLS-apex, % 17.50 (12.25, 25.75) 18.00 (15.00, 26.00) 17.00 (12.00, 25.50) Z=-0.283 0.777 IVSLS-base, % 26.49 ± 7.97 26.76 ± 8.92 26.17 ± 6.88 t = 0.262 0.795 IVSLS-mid, % 22.99 ± 5.23 23.68 ± 5.49 22.17 ± 4.90 t = 1.014 0.315 IVSLS-apex, % 21.52 ± 8.88 22.27 ± 8.94 20.65 ± 8.93 t = 0.637 0.527 RV and pulmonary reserve mPAP/CO slope, mmHg /L/min 2.70 ± 1.31 1.97 ± 1.13 3.17 ± 1.25 t = 2.364 0.022 ΔTAPSE, mm 5.79 ± 2.86 5.29 ± 3.02 5.77 ± 2.67 t=-0.033 0.974 ΔFAC, % 10.86 ± 4.92 12.22 ± 5.35 8.26 ± 3.89 t=-2.200 0.033 ΔTV s′, m/s 0.06 ± 0.04 0.08 ± 0.03 0.05 ± 0.04 t=-2.856 0.006 ΔSPAP, mmHg 17.39 ± 7.95 13.21 ± 6.22 20.42 ± 8.13 t = 2.516 0.015 ΔmPAP, mmHg 10.42 ± 4.78 7.89 ± 3.74 12.25 ± 4.88 t = 2.531 0.015 Delta B-line (≥ 1) 9 (18%) 2 (7%) 7(30%) 4.462 0.035 ΔPVR, WU 0.32 ± 0.19 0.30 ± 0.17 0.40 ± 0.19 t = 2.681 0.010 Left heart parameters E (cm/s) 1.23 ± 0.20 1.26 ± 0.18 1.18 ± 0.22 t = 1.401 0.168 A (cm/s) 1.10 ± 0.22 1.10 ± 0.24 1.10 ± 0.21 t=-0.093 0.926 MV e′,cm/s 0.18 ± 0.03 0.17 ± 0.03 0.19 ± 0.02 t=-1.977 0.054 MV a′,cm/s 0.14 ± 0.04 0.14 ± 0.04 0.16 ± 0.05 t=-2.410 0.020 E/e′ ratio 7.87 ± 1.54 8.21 ± 1.52 7.47 ± 1.50 t = 1.730 0.090 LVEF, % 76.75 ± 3.55 76.79 ± 3.94 76.70 ± 3.11 t = 0.095 0.924 CO, L/min 8.34 ± 1.30 8.42 ± 1.19 8.25 ± 1.44 t = 0.462 0.646 Δ, change from rest to peak exercise; B-line, ultrasound lung comet-tail artifact (≥ 1 defined as abnormal). Other abbreviations are as defined in Table 2 . Analysis of functional reserve revealed that the AMS group demonstrated significantly smaller increases in ΔTV s′ (p = 0.006) and ΔFAC (p = 0.033), while ΔTAPSE did not differ significantly between groups (p = 0.974) (Table 3 ). AMS Prediction Model Based on univariable logistic regression, the following variables were significantly associated with AMS and were included as candidate predictors: SPAP at rest, TV s′ at rest, TAPSE/SPAP at rest, IVC at peak exercise, mPAP at peak exercise, PVR at peak exercise, SPAP at peak exercise, and TR at peak exercise, mPAP/CO slope, ΔPVR, ΔTV s′ (all P < 0.05) (Supplemental Table 1). These variables were entered into a multivariable stepwise logistic regression model with entry and retention set at P < 0.05. The final model identified three independent predictors of AMS: ΔPVR (P = 0.005), IVC-peak (P = 0.024), and ΔTV s′ (P = 0.047) (Table 4 ). Table 4 Multivariate logistic regression analysis of the predictors of AMS Variables β S. E Z P OR (95%CI) Intercept -5.21 2.28 -2.28 0.022 0.01 (0.00 ~ 0.48) ΔTV s′, m/s -0.21 0.11 -1.99 0.047 0.81 (0.66 ~ 0.99) ΔPVR, WU 0.07 0.02 2.82 0.005 1.07 (1.02 ~ 1.13) IVC-peak,mm 0.30 0.13 2.25 0.024 1.35 (1.04 ~ 1.75) β, regression coefficient; S.E., standard error; OR, odds ratio; CI, confidence interval. Variables: ΔTV s′, change in tricuspid annular peak systolic velocity from rest to peak exercise; ΔPVR, change in pulmonary vascular resistance from rest to peak exercise; IVC-peak, inferior vena cava diameter at peak exercise. These three indicators were subsequently integrated to construct a new predictive nomogram model (Fig. 3 A), which demonstrated superior predictive performance compared to any individual indicator (nomogram: AUC, 0.865 [95% CI, 0.760–0.969]; ΔPVR: cutoff, 0.375, AUC, 0.763 [95% CI, 0.626–0.900]; IVC-peak: cutoff, 13.5, AUC, 0.680 [95% CI, 0.527–0.834]; ΔTV s′: cutoff, 0.045, AUC, 0.713 [95% CI, 0.565–0.860]; Fig. 3 B). The nomogram model achieved a sensitivity of 0.783 (95% CI, 0.614–0.951) and a specificity of 0.889 (95% CI, 0.770–1.000). Bootstrap internal validation (1,000 resamples) confirmed good calibration of the model, as shown by the close alignment between predicted probabilities and actual AMS incidence in the calibration curve (Fig. 3 C). DCA indicated favorable net benefit across a wide range of threshold probabilities (Supplemental Fig. 1). Furthermore, CIC (Fig. 3 D) illustrated the relationship between the number of individuals classified as high-risk (solid red line) and the number of true events (dashed blue line). Close alignment of the two curves at lower risk thresholds reflected high clinical predictive performance; increasing divergence suggested reduced sensitivity at higher thresholds. Both the individual predictors (ΔPVR, IVC-peak, ΔTV s′; Supplemental Figs. 2A,2B,2C) and the integrated nomogram exhibited excellent predictive value within an optimal risk-threshold range, with the nomogram demonstrating particularly robust performance (Fig. 3 D). This combined approach effectively enhances clinical decision-making for AMS risk assessment. Discussion This study provides unique insights into the compensatory insufficiency of the pulmonary vasculature and RV systolic function in AMS. We demonstrate that despite comparable resting RV and pulmonary vascular function between AMS and non-AMS subjects, AMS patients exhibit impaired pulmonary vascular reserve, diminished RV contractile reserve, increased B-lines and IVC enlargement during exercise. The nomogram incorporating IVC-peak, ΔTV s′, and ΔPVR demonstrated excellent predictive performance, providing an objective tool for early identification of high-risk AMS individuals and guiding decisions regarding high-altitude exposure. Comparison with Previous Studies Excessive PAP elevation induced by hypoxia represents a fundamental pathophysiological mechanism in HAPE. Previous investigations in HAPE-susceptible individuals have demonstrated significantly greater PAP increases and elevated PVR during hypoxic exercise compared to healthy controls, who typically show PVR reduction [ 16 , 17 ] , findings consistent with low-altitude observations [ 4 ] and reports in Chronic Mountain Sickness (CMS) patients at high altitude [ 18 ] . In our study, both AMS and non-AMS subjects exhibited increased PVR and PAP during exercise, but the AMS group demonstrated significantly greater increases. This response during high-altitude exercise may stem from impaired hypoxic ventilatory response in AMS individuals, leading to enhanced hypoxic pulmonary vasoconstriction and ventilation/perfusion mismatch – key mechanisms underlying the elevated PAP and PVR observed in AMS subjects compared to non-AMS [ 19 ] . This pathophysiological process likely involves imbalance between vasoconstrictive and vasodilatory forces, potentially combined with reduced pulmonary vasodilatory activity in AMS individuals [ 20 ] . We hypothesize that high-altitude hypoxia compromises pulmonary vascular capacitance. While non-AMS individuals at low altitude can compensate for exercise-induced blood flow increases through pulmonary vasodilation and PVR reduction [ 21 ] , AMS subjects at high altitude experience more substantial pulmonary vasodilation limitations, resulting in markedly greater PAP and PVR elevations during exercise. Although capillary distension to reduce resistance may represent an adaptive exercise response, this mechanism becomes limited by hypoxemia from altered diffusion/perfusion relationships [ 22 ] . The elevated mPAP/CO slope in AMS subjects further indicates reduced pulmonary vascular distensibility, leading to disproportionate PAP elevations with increasing CO. Elevated PAP demands enhanced RV contractility. In pulmonary hypertension (PH) patients, survival depends on RV adaptation to persistent high PAP. Previous studies indicate that PH patients with compromised RV contractile reserve have a poorer prognosis [ 23 ] . RV contractile reserve is crucial for maintaining effective RV-pulmonary artery coupling and stability during exercise stress, with its reduction serving as an early marker of RV compensatory insufficiency [ 24 ] . Pratali et al. demonstrated significant TV s′ increases in healthy subjects but minimal changes in CMS patients, indicating reduced RV contractility reserve [ 18 ] . Similarly, our study revealed smaller TV s′ and FAC increases in the AMS group compared to non-AMS group, suggesting less efficient functional compensation despite preserved RV systolic reserve, a pattern distinct from low-altitude observations [ 4 ] . Various indices of RV contractile reserve present distinct advantages and limitations. While TAPSE and TV s′ primarily assess longitudinal motion, FAC evaluates both longitudinal and radial contraction components. LS offers advantages in detecting subclinical RV dysfunction earlier than traditional parameters, though post-exercise image tracking presents technical challenges in some subjects [ 25 ] . Our findings indicate that although RV function was temporarily maintained through enhanced longitudinal contraction or regional compensation [ 26 ] , the reduced ΔFAC and ΔTV s′ consistently demonstrated decreased contractile reserve in AMS compared to non-AMS. Despite higher PAP and consequent RV afterload in AMS subjects, coupling parameters including TV s′/SPAP and TAPSE/SPAP ratios remained within normal ranges, though AMS subjects exhibited lower coupling efficiency compared to non-AMS. This coupling reduction likely originates from abnormal RV-pulmonary artery interaction secondary to elevated SPAP [ 27 ] . While previous investigations, including Forbes et al. reported maintained RV-pulmonary artery coupling during hypoxic exercise in healthy individuals [ 28 ] , our results demonstrate subtle but clinically relevant decreases in AMS subjects, indicating impaired RV-pulmonary artery coupling and diminished capacity to cope with physiological stressors like exercise. In response to high RV afterload, compensatory mechanisms maintain CO by elevating HR and venous return (preload), resulting in increased right atrial pressure and IVC diameter [ 29 ] . Both at low and high altitudes, the AMS group exhibited wider IVC during exercise despite comparable HR. This finding represents an early compensatory response to elevated right heart pressure and serves as a key imaging marker of venous congestion in AMS [ 30 ] .Although B-lines were not retained as an ultimate independent predictor in the multivariate model, the increased B-lines observed in the AMS group reflect subclinical pulmonary interstitial edema resulting from exaggerated pulmonary hypertension during exercise [ 31 ] . Collectively, the concurrent enlargement of IVC and increased B-lines delineate a hemodynamic continuum of right heart load and pulmonary fluid accumulation in AMS-susceptible individuals under high-altitude exertion. Clinical Implications While previous investigations have explored various cardiovascular AMS predictors including SpO2 [ 32 ] , pulse pressure, effective arterial elastance [ 33 ] , and mitral annular displacement [ 34 ] , our prior work specifically identified low-altitude parameters including peak exercise PVR, IVC diameter, and B-line counts as AMS predictors [ 4 ] . However, studies predicting AMS development in individuals already at high altitude remain limited. Current evidence indicates that subjects exhibiting greater SPO 2 decreases during high-altitude exercise demonstrate increased AMS susceptibility, though this observation was documented on day 7 post-exposure [ 35 ] . The distinctive feature of our study lies in its focus on physiological stress responses during the initial 6 hours of high-altitude exposure. Our comprehensive quantification of echocardiographic indices during rest and exercise under real-world high-altitude conditions not only enhances understanding of cardiopulmonary adaptive differences in AMS subjects but also establishes ESE-derived parameters as predictive indicators for next-day AMS occurrence. This provides a clinically actionable risk stratification tool that may prevent progression to severe high-altitude illnesses. The rapid, cost-effective ESE protocol we propose completes risk assessment within 15 minutes, making it particularly suitable for on-site screening before further ascent. This tool offers potential value for all mountaineers and could guide personalized interventions including graded ascent, pre-acclimatization training, or targeted pharmacological prevention. Limitations Several limitations warrant consideration. First, although the sample size was relatively modest, all subjects were selected using strict inclusion and exclusion criteria. Second, excluding subjects without measurable tricuspid regurgitation may limit generalizability to this specific population. Third, we utilized non-invasive rather than invasive hemodynamic assessment for pulmonary hemodynamics, though the latter remains the gold standard but presents substantial ethical and logistical challenges. Finally, the generalizability of our findings beyond healthy Han Chinese adults remains uncertain for other ethnicities, age groups, and individuals with comorbidities, as well as for the highly variable individual physiological responses to high-altitude exposure. Conclusion To our knowledge, this is the first study to comprehensively evaluate biventricular function and pulmonary circulation during rest and exercise within 6 hours of high-altitude exposure in individuals who subsequently developed AMS. Our findings demonstrate that AMS subjects exhibit a distinct phenotype characterized by elevated PAP and PVR during exercise, accompanied by decreased pulmonary vascular reserve, reduced RV contractile reserve, mildly diminished exercise capacity, and evidence of intravascular (IVC enlargement) and pulmonary extravascular (B-lines) congestion. LV systolic and diastolic function remained preserved in these subjects. Importantly, ESE effectively detected these early alterations in the right heart-pulmonary circulatory system and demonstrated predictive value for identifying AMS-susceptible individuals. Future studies should focus on validating the proposed predictive thresholds and assessing their value in guiding ESE-driven preventive therapeutic interventions. Abbreviations Abbreviation Full Term AMS Acute Mountain Sickness AUC Area Under the Curve CI Confidence Interval CMS Chronic Mountain Sickness CIC clinical impact curves CO Cardiac Output DBP Diastolic Blood Pressure DCA Decision curve analysis ESE Exercise Stress Echocardiography FAC Fractional Area Change FWLS Free Wall Longitudinal Strain HACE High-Altitude Cerebral Edema HAPE High-Altitude Pulmonary Edema HR Heart Rate IVC Inferior Vena Cava IVSLS Interventricular Septum Longitudinal Strain LLS Lake Louise Score LS Longitudinal Strain LVEF Left Ventricular Ejection Fraction mPAP Mean Pulmonary Artery Pressure OR Odds Ratio PAP Pulmonary Arterial Pressure PAWP Pulmonary Artery Wedge Pressure PH Pulmonary Hypertension PVR Pulmonary Vascular Resistance RV Right Ventricular RVD Right Ventricular Diameter RVGLS Right Ventricular Global Longitudinal Strain SBP Systolic Blood Pressure SpO2 Oxygen Saturation SPAP Systolic Pulmonary Artery Pressure TAPSE Tricuspid Annular Plane Systolic Excursion TRV Tricuspid Regurgitation Velocity TV s′ Tricuspid Annular Peak Systolic Velocity Δ change from rest to peak exercise Declarations Ethics approval and consent to participate. The study protocol was approved by the Institutional Research and Ethical Committees of Sichuan Provincial People′s Hospital (Approval No. 2023-436). All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study. Consent for publication Written informed consent for publication was obtained from all participants. Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author (Yi Wang) on reasonable request. Competing interests None. Funding This work was supported by the Sichuan Provincial Medical Research Project (Grant Number S2024007 to Yi Wang). Authors′ contributions Yun Xu: Formal analysis, Investigation, Writing - Original Draft. Sijia Wang: Formal analysis, Investigation, Writing - Original Draft. Yong Jing: Data Curation. Qingfeng Zhang: Methodology, Resources, Validation. Kai Wang: Software, Visualization. Yan Deng: Investigation. JingXue Fan: Investigation. Lixue Yin: Conceptualization, Supervision, Project administration, Writing - Review & Editing. Yi Wang: Conceptualization, Supervision, Funding acquisition, Writing - Review & Editing. All authors reviewed the manuscript. Acknowledgements we would like to thank the National Emergency Rescue Team for logistical support, Dr. Yan Yang for imaging assistance, and Nurse Pei Fu for participant recruitment. References Imray C, Wright A, Subudhi A, et al. Acute mountain sickness: Pathophysiology, prevention, and treatment[J]. Prog Cardiovasc Dis. 2010;52(6):467–84. 10.1016/j.pcad.2010.02.003 . Basnyat B, Murdoch DR. High-altitude illness[J]. Lancet. 2003;361(9373):1967–74. 10.1016/s0140-6736(03)13591-x . Williams AM, Levine BD. Stembridge M.A change of heart: Mechanisms of cardiac adaptation to acute and chronic hypoxia[J]. J Physiol. 2022;600(18):4089–104. 10.1113/JP281724 . Wang Y, Zhang Q, Wang K, et al. Supine bicycle stress echocardiography at low altitude for identification of susceptibility to acute mountain sickness[J]. J Am Soc Echocardiogr. 2025;38(3):262–72. 10.1016/j.echo.2024.12.007 . Ke J, Liu C, Yu S et al. Low stroke volume index in healthy young men is associated with the incidence of acute mountain sickness after an ascent by airplane: A case-control study[J]. Biomed Res Int, 2020, 2020:6028747. 10.1155/2020/6028747 Bian SZ, Jin J, Zhang JH, et al. Principal component analysis and risk factors for acute mountain sickness upon acute exposure at 3700 m[J]. PLoS ONE. 2015;10(11):e0142375. 10.1371/journal.pone.0142375 . Gargani L, Pugliese NR, De Biase N, et al. Exercise stress echocardiography of the right ventricle and pulmonary circulation[J]. J Am Coll Cardiol. 2023;82(21):1973–85. 10.1016/j.jacc.2023.09.807 . Pellikka PA, Arruda-Olson A, Chaudhry FA, et al. Guidelines for performance, interpretation, and application of stress echocardiography in ischemic heart disease: From the american society of echocardiography[J]. J Am Soc Echocardiogr. 2020;33(1):1–e4148. 10.1016/j.echo.2019.07.001 . Roach RC, Hackett PH, Oelz O, et al. The 2018 lake louise acute mountain sickness score[J]. High Alt Med Biol. 2018;19(1):4–6. 10.1089/ham.2017.0164 . Picano E, Pierard L, Peteiro J, et al. The clinical use of stress echocardiography in chronic coronary syndromes and beyond coronary artery disease: A clinical consensus statement from the european association of cardiovascular imaging of the esc[J]. Eur Heart J Cardiovasc Imaging. 2024;25(2):e65–90. 10.1093/ehjci/jead250 . Lancellotti P, Pellikka PA, Budts W, et al. The clinical use of stress echocardiography in non-ischaemic heart disease: Recommendations from the european association of cardiovascular imaging and the american society of echocardiography[J]. Eur Heart J Cardiovasc Imaging. 2016;17(11):1191–229. 10.1093/ehjci/jew190 . Lang RM, Badano LP, Mor-Avi V, et al. Recommendations for cardiac chamber quantification by echocardiography in adults: An update from the american society of echocardiography and the european association of cardiovascular imaging[J]. Eur Heart J Cardiovasc Imaging. 2015;16(3):233–70. 10.1093/ehjci/jev014 . Chemla D, Castelain V, Humbert M, et al. New formula for predicting mean pulmonary artery pressure using systolic pulmonary artery pressure[J]. Chest. 2004;126(4):1313–7. 10.1378/chest.126.4.1313 . Nagueh SF, Middleton KJ, Kopelen HA, et al. Doppler tissue imaging: A noninvasive technique for evaluation of left ventricular relaxation and estimation of filling pressures[J]. 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JACC Cardiovasc Imaging. 2013;6(12):1287–97. 10.1016/j.jcmg.2013.08.007 . Pigman EC. Acute mountain sickness. Effects and implications for exercise at intermediate altitudes[J]. Sports Med. 1991;12(2):71–9. 10.2165/00007256-199112020-00001 . Sylvester JT, Shimoda LA, Aaronson PI, et al. Hypoxic pulmonary vasoconstriction[J]. Physiol Rev. 2012;92(1):367–520. 10.1152/physrev.00041.2010 . Naeije R. Chesler N.Pulmonary circulation at exercise[J]. Compr Physiol. 2012;2(1):711–41. 10.1002/cphy.c100091 . Steenhorst JJ, Hirsch A, Verzijl A, et al. Exercise and hypoxia unmask pulmonary vascular disease and right ventricular dysfunction in a 10- to 12-week-old swine model of neonatal oxidative injury[J]. J Physiol. 2022;600(17):3931–50. 10.1113/jp282906 . Hsu S, Houston BA, Tampakakis E, et al. Right ventricular functional reserve in pulmonary arterial hypertension[J]. Circulation. 2016;133(24):2413–22. 10.1161/circulationaha.116.022082 . Haddad F, Hunt SA, Rosenthal DN, et al. Right ventricular function in cardiovascular disease, part i: Anatomy, physiology, aging, and functional assessment of the right ventricle[J]. Circulation. 2008;117(11):1436–48. 10.1161/circulationaha.107.653576 . Nonaka H, Rätsep I, Obonyo NG, et al. Current trends and latest developments in echocardiographic assessment of right ventricular function: Load dependency perspective[J]. Front Cardiovasc Med. 2024;11:1365798. 10.3389/fcvm.2024.1365798 . Kjaergaard J, Snyder EM, Hassager C, et al. Right ventricular function with hypoxic exercise: Effects of sildenafil[J]. Eur J Appl Physiol. 2007;102(1):87–95. 10.1007/s00421-007-0560-2 . Vonk Noordegraaf A, Westerhof BE. Westerhof N.The relationship between the right ventricle and its load in pulmonary hypertension[J]. J Am Coll Cardiol. 2017;69(2):236–43. 10.1016/j.jacc.2016.10.047 . Forbes LM, Bull TM, Lahm T, et al. Right ventricular performance during acute hypoxic exercise[J]. J Physiol. 2024;602(21):5523–37. 10.1113/jp284943 . Yang JH, Harada T, Choi KH, et al. Peripheral venous pressure-assisted exercise stress echocardiography in the evaluation of pulmonary hypertension during exercise in patients with suspected heart failure with preserved ejection fraction[J]. Circ Heart Fail. 2022;15(3):e009028. 10.1161/circheartfailure.121.009028 . Konstam MA, Kiernan MS, Bernstein D, et al. Evaluation and management of right-sided heart failure: A scientific statement from the american heart association[J]. Circulation. 2018;137(20):e578–622. 10.1161/cir.0000000000000560 . Agricola E, Bove T, Oppizzi M, et al. Ultrasound comet-tail images: A marker of pulmonary edema: A comparative study with wedge pressure and extravascular lung water[J]. Chest. 2005;127(5):1690–5. 10.1378/chest.127.5.1690 . Shen Y, Yang YQ, Liu C, et al. Association between physiological responses after exercise at low altitude and acute mountain sickness upon ascent is sex-dependent[J]. Mil Med Res. 2020;7(1):53. 10.1186/s40779-020-00283-3 . Chen R, Sun M, Yang J, et al. Cardiovascular indicators of systemic circulation and acute mountain sickness: An observational cohort study[J]. Front Physiol. 2021;12:708862. 10.3389/fphys.2021.708862 . Ke J, Yang J, Liu C, et al. A novel echocardiographic parameter to identify individuals susceptible to acute mountain sickness[J]. Travel Med Infect Dis. 2021;44:102166. 10.1016/j.tmaid.2021.102166 . Seiler T, Nakas CT, Brill AK, et al. Do cardiopulmonary exercise tests predict summit success and acute mountain sickness? A prospective observational field study at extreme altitude[J]. Br J Sports Med. 2023;57(14):906–13. 10.1136/bjsports-2022-106211 . Additional Declarations No competing interests reported. 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14:55:49","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8777421/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8777421/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104343575,"identity":"e7653fb3-a3ff-439b-bbd1-ce629c5621c9","added_by":"auto","created_at":"2026-03-10 17:12:45","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":69284,"visible":true,"origin":"","legend":"\u003cp\u003eParticipant screening and group assignment diagram\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8777421/v1/d2619adc4db8feb309b90565.jpg"},{"id":104343574,"identity":"d91e87f3-63c1-4873-a2bc-938d4a68f93c","added_by":"auto","created_at":"2026-03-10 17:12:45","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":71055,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart of this study.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8777421/v1/d149563c460bd0b96caa4baf.jpg"},{"id":104343576,"identity":"c4f304fe-4ca3-4f20-be9f-8487c82b9c6e","added_by":"auto","created_at":"2026-03-10 17:12:45","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":133165,"visible":true,"origin":"","legend":"\u003cp\u003eDevelopment and evaluation of the predictive nomogram for acute mountain sickness.\u003c/p\u003e\n\u003cp\u003e(A). AMS Prediction Nomogram: This nomogram estimates the probability of AMS based on three parameters: ΔPVR, ΔTV-s', and IVC-peak. Points assigned for each variable are summed and projected downward to obtain the predicted AMS risk; (B). ROC Curves and Discriminative Performance: The nomogram model demonstrates superior discriminative ability (AUC = 0.865) compared to individual predictors (IVC-peak, ΔPVR, ΔTV-s′); (C). Calibration Curves of the Prediction Model: The figure presents the calibration curves of the prediction model, showing the agreement between the predicted probabilities (blue solid line), the bias-corrected predicted probabilities (orange dashed line), and the ideal calibration line (black dashed line); (D). Clinical Impact Curve Analysis: The figure presents a clinical impact curve analysis, demonstrating that the integrated nomogram model exhibits excellent predictive value and an optimal risk threshold range for clinical application.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8777421/v1/871e56d24ef09748a583dc09.jpg"},{"id":104406032,"identity":"24fe4904-867e-48ac-92e4-e2f90b785e5f","added_by":"auto","created_at":"2026-03-11 12:24:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1315629,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8777421/v1/cc49e936-fc35-4948-88de-86f5a704d01b.pdf"},{"id":104343577,"identity":"30137f4f-0e65-4a90-af1c-7ac6812b801e","added_by":"auto","created_at":"2026-03-10 17:12:45","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":433466,"visible":true,"origin":"","legend":"","description":"","filename":"2026.Supplemental.docx","url":"https://assets-eu.researchsquare.com/files/rs-8777421/v1/910751bd7e94610e296e8aec.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Early detection of acute mountain sickness after high-altitude exposure","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAcute mountain sickness (AMS), the most common acute high-altitude illness, typically affects individuals who ascend rapidly to elevations above 2,500 meters without adequate acclimatization. Its incidence ranges from 25% to 85% within the 2,500\u0026ndash;4,500 meter altitude range \u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. AMS is characterized by symptoms such as headache, dizziness, gastrointestinal disturbances, and fatigue, which usually begin within hours of high-altitude exposure and peak in severity on the first night. In severe cases, AMS can progress to life-threatening complications, including high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE) \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e .\u003c/p\u003e \u003cp\u003eAlthough the cardiovascular system does not directly sense changes in ambient oxygen partial pressure, its compensatory responses, particularly those of the right ventricular (RV)-pulmonary circulation unit, are crucial for systemic adaptation to hypoxia\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eAt rest, studies have shown that AMS patients exhibit RV and pulmonary circulatory function comparable to the non-AMS group both at low altitude and high-altitude exposure \u003csup\u003e[\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. Exercise stress testing is well established as a sensitive method for detecting latent changes in pulmonary circulation and RV function \u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Our previous research during peak exercise at low altitude demonstrated that although AMS-susceptible individuals maintain RV function and contractile reserve similar to non-AMS subjects, they exhibit elevated pulmonary arterial pressure (PAP), increased pulmonary vascular resistance (PVR), larger inferior vena cava (IVC) diameter, and higher B-line counts after exercise. These parameters significantly predict subsequent AMS development \u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eNotably, no study has yet comprehensively characterized the RV-pulmonary circulation unit in AMS-susceptible individuals during exercise following high-altitude exposure. To address this gap, we hypothesized that exercise stress echocardiography (ESE) can detect differences in RV-pulmonary circulatory responses between AMS and non-AMS subjects within the first few hours at moderate high altitude. This study aimed to evaluate these differential responses and assess their predictive validity for AMS occurrence. The noninvasive identification of an AMS-vulnerable phenotype could provide a theoretical basis for guiding decisions regarding continued high-altitude exposure and further ascent.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cp\u003eStudy Setting and Ethics\u003c/p\u003e \u003cp\u003eThis prospective cohort study was conducted in Xinduqiao Town, Kangding, Sichuan Province, China, at an average altitude of 3,600 meters. The study protocol received approval from the Institutional Research and Ethical Committees of Sichuan Provincial People\u0026prime;s Hospital (Approval No. 2023\u0026thinsp;\u0026minus;\u0026thinsp;436) and adhered to the Declaration of Helsinki. Written informed consent was obtained from all participants prior to any study procedures.\u003c/p\u003e \u003cp\u003eStudy Population\u003c/p\u003e \u003cp\u003eFifty-seven healthy low-altitude residents were initially enrolled. Exclusion criteria included: known cardiovascular disease, ongoing cardiovascular treatments, multiple exposures to altitudes above 2,500 meters within the previous six months, history of severe mountain sickness, angioedema, pregnancy, fertile women not using effective contraception, and professional athletes. All participants underwent comprehensive health screening before inclusion.\u003c/p\u003e \u003cp\u003eAfter initial recruitment, seven subjects were excluded: two developed significant headaches upon arrival and did not undergo stress echocardiography for safety reasons; four had inadequate tricuspid regurgitation Doppler images (one at rest, three at peak exercise); and one declined participation. The final analysis included 50 participants (31 males, 19 females; mean age 35\u0026thinsp;\u0026plusmn;\u0026thinsp;7 years) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eStudy Protocol\u003c/p\u003e \u003cp\u003eParticipants ascended by bus over 24 hours, with an overnight rest at 2,150 meters before reaching the final altitude of 3,600 meters. Following arrival, participants rested for 3 hours before undergoing supine bicycle ESE within the first 6 hours of high-altitude exposure. Oxygenation and general health status were continuously monitored throughout.\u003c/p\u003e \u003cp\u003eOn the morning following arrival, participants completed the 2018 Lake Louise Score (LLS) questionnaire \u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. AMS was defined as a total score\u0026thinsp;\u0026ge;\u0026thinsp;3 points, including at least one point for headache. Participants with scores\u0026thinsp;\u0026lt;\u0026thinsp;3 were classified as non-AMS (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eESE\u003c/h2\u003e \u003cp\u003eExercise testing was performed using a semi-recumbent cycle ergometer (Ergoselect II 1200; Ergoline, Bitz, Germany). Standard transthoracic echocardiography was conducted at rest and during exercise using a commercial ultrasound system (Vivid E95, GE Vingmed Ultrasound) with a 3.5-MHz M5S transducer.\u003c/p\u003e \u003cp\u003eThe exercise protocol consisted of incremental cycling at 60 revolutions per minute, beginning with a 2-minute unloaded phase followed by stepwise increases of 25 W every 2 minutes until volitional exhaustion. Participants' oxygenation, blood pressure, heart rate (HR), and electrocardiogram were continuously monitored throughout the procedure. All image acquisitions followed standardized protocols\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e and were performed by the same physician.\u003c/p\u003e \u003cp\u003eEchocardiographic Analysis\u003c/p\u003e \u003cp\u003eAll echocardiographic parameters were measured offline according to current guidelines of the American Society of Echocardiography and the European Association of Cardiovascular Imaging, including the specific recommendations for stress echocardiography \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. Image analysis was performed offline using Echo PAC software (version 204, General Electric Vingmed Ultrasound)\u003c/p\u003e \u003cp\u003eComprehensive assessment included: Left ventricular ejection fraction (LVEF) using biplane Simpson\u0026prime;s method, Cardiac output (CO) derived from left ventricular outflow tract diameter, time velocity integral, and heart rate, RV fractional area change (FAC), Tricuspid regurgitation velocity (TRV) using continuous-wave Doppler, Tricuspid annular peak systolic velocity (TV s\u0026prime;) using tissue Doppler, Pulmonary artery systolic pressure (SPAP) estimated from TRV and right atrial pressure, Mean pulmonary artery pressure (mPAP) calculated as 0.6 \u0026times; SPAP\u0026thinsp;+\u0026thinsp;2 mmHg\u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e, Pulmonary vascular resistance (PVR) estimated using the formula: (mPAP - PAWP)/CO, with pulmonary artery wedge pressure (PAWP) estimated from E/e\u0026prime; ratio\u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e, Tricuspid annular plane systolic excursion (TAPSE), RV-pulmonary artery coupling indices (TAPSE/SPAP, TV s\u0026prime;/SPAP) and mPAP/CO relationship. Automated functional imaging was employed to assess RV longitudinal strain (LS), with manual adjustment of the region of interest as needed to ensure accurate wall tracking. Strain analysis included the following specific parameters: right ventricular global longitudinal strain (RVGLS), free wall longitudinal strain (FWLS) with its segments\u0026mdash;free wall basal segment longitudinal strain (FWLS-base), free wall mid segment longitudinal strain (FWLS-mid), and free wall apical segment longitudinal strain (FWLS-apex)\u0026mdash;as well as interventricular septal longitudinal strain segments comprising interventricular septal basal segment longitudinal strain (IVSLS-base), interventricular septal mid segment longitudinal strain (IVSLS-mid), and interventricular septal apical segment longitudinal strain (IVSLS-apex).Lung ultrasound was performed using a simplified 2-site scan (third intercostal space, from mid-axillary to anterior axillary line bilaterally), with abnormal response defined as \u0026ge;\u0026thinsp;1 B-lines\u003csup\u003e[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e.Functional reserve parameters (Δ) were calculated as the difference between peak exercise and resting values for FAC, TAPSE, TV s\u0026prime;, SPAP, mPAP, PVR, and B-lines.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eAll statistical analyses were performed using SPSS (version 26.0; IBM Corp.) and R (version 3.6.1). Categorical variables are presented as numbers and percentages and were compared using the chi-square test. Continuous variables were tested for normality using the Shapiro\u0026ndash;Wilk test. Normally distributed variables are expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation and compared using the independent-samples t-test, while non-normally distributed variables are summarized as median with interquartile range and compared using the Mann\u0026ndash;Whitney U test.\u003c/p\u003e \u003cp\u003eTo identify independent predictors of AMS, multivariable logistic regression analysis with stepwise selection (both forward and backward) was performed. Variables showing a significant univariable association with AMS (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) were included as candidates in the initial model. Variable entry and retention were based on a significance level of P\u0026thinsp;\u0026lt;\u0026thinsp;0.05, and removal was set at P\u0026thinsp;\u0026ge;\u0026thinsp;0.10.\u003c/p\u003e \u003cp\u003eThe performance of the final model was comprehensively evaluated using R software. A nomogram was constructed based on the regression coefficients to visualize the individualized prediction of AMS risk. Model calibration was assessed using a calibration curve with 1,000 bootstrap resamples, along with the calibration intercept and slope. Discriminatory ability was measured by the area under the receiver operating characteristic curve (AUC), which was plotted using the pROC package. Decision curve analysis (DCA) was performed to evaluate the clinical net benefit across a range of threshold probabilities. Finally, clinical impact curves (CIC) were plotted to illustrate the actual number of high-risk individuals identified versus the number of true events at different risk thresholds, providing quantitative guidance for clinical decision-making.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eIncidence of AMS and Clinical Characteristics\u003c/p\u003e \u003cp\u003eAt 3,600 m, 23 of the 50 subjects (46%) were diagnosed with AMS (AMS group), while the remaining 27 (54%) comprised the non-AMS group. Among all participants, headache was reported by 35 individuals (70%), gastrointestinal symptoms by 8 (16%), fatigue and/or weakness by 26 (52%), and dizziness or light-headedness by 22 (44%) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). No statistically significant differences were observed between the two groups in baseline characteristics, including sex distribution, age, body surface area, body mass index, heart rate, blood pressure, or oxygen saturation (all p\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDistribution and Incidence rates of AMS-related symptoms (50 subjects)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSymptom\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 points\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 point\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 points\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3 points\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eincidence\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHeadache\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGastrointestinal symptoms\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.16\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFatigue and/or weakness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.52\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDizziness/light-headedness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.44\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline characteristics and resting echocardiographic parameters at 3600 m..\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003eREST\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eall\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003enon-AMS N\u0026thinsp;=\u0026thinsp;27\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAMS N\u0026thinsp;=\u0026thinsp;23\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003et/z/χ\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eBasic characteristics\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex, male (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34(68%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16(59%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18(78%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eχ\u0026sup2;=2.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.147\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, yrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e39\u0026thinsp;\u0026plusmn;\u0026thinsp;8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39\u0026thinsp;\u0026plusmn;\u0026thinsp;7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40\u0026thinsp;\u0026plusmn;\u0026thinsp;7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.574\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.569\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmoking, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11(22%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(15%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7(30%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eχ\u0026sup2;=1.750\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.186\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBSA (m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.74\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.158\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.875\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.96\u0026thinsp;\u0026plusmn;\u0026thinsp;3.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.06\u0026thinsp;\u0026plusmn;\u0026thinsp;3.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.82\u0026thinsp;\u0026plusmn;\u0026thinsp;3.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.233\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.816\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHR, b/m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e93.14\u0026thinsp;\u0026plusmn;\u0026thinsp;11.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e92.30\u0026thinsp;\u0026plusmn;\u0026thinsp;11.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e94.13\u0026thinsp;\u0026plusmn;\u0026thinsp;12.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.556\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.581\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSBP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e123.96\u0026thinsp;\u0026plusmn;\u0026thinsp;12.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e123.11\u0026thinsp;\u0026plusmn;\u0026thinsp;14.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e124.96\u0026thinsp;\u0026plusmn;\u0026thinsp;10.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.499\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.620\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDBP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e81.60\u0026thinsp;\u0026plusmn;\u0026thinsp;12.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79.78\u0026thinsp;\u0026plusmn;\u0026thinsp;14.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e83.74\u0026thinsp;\u0026plusmn;\u0026thinsp;9.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.144\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.258\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpO2, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e84.42\u0026thinsp;\u0026plusmn;\u0026thinsp;4.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e84.26\u0026thinsp;\u0026plusmn;\u0026thinsp;4.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e84.61\u0026thinsp;\u0026plusmn;\u0026thinsp;4.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.288\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.774\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eRight heart and pulmonary circulation parameters\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTRV, m/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.332\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.189\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTV s\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.579\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.135\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTV e\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.470\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.641\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTV a\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.314\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTAPSE, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20.90\u0026thinsp;\u0026plusmn;\u0026thinsp;2.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20.52\u0026thinsp;\u0026plusmn;\u0026thinsp;2.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21.35\u0026thinsp;\u0026plusmn;\u0026thinsp;3.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.998\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.323\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSPAP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33.08\u0026thinsp;\u0026plusmn;\u0026thinsp;7.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.86\u0026thinsp;\u0026plusmn;\u0026thinsp;7.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e34.51\u0026thinsp;\u0026plusmn;\u0026thinsp;7.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.267\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.211\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emPAP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.86\u0026thinsp;\u0026plusmn;\u0026thinsp;4.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.14\u0026thinsp;\u0026plusmn;\u0026thinsp;4.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.71\u0026thinsp;\u0026plusmn;\u0026thinsp;4.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.246\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.219\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePVR, WU\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.606\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.548\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRVD1, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31.44\u0026thinsp;\u0026plusmn;\u0026thinsp;4.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.96\u0026thinsp;\u0026plusmn;\u0026thinsp;4.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32.00\u0026thinsp;\u0026plusmn;\u0026thinsp;4.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.876\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.385\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRVD2, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.52\u0026thinsp;\u0026plusmn;\u0026thinsp;4.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.15\u0026thinsp;\u0026plusmn;\u0026thinsp;3.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30.96\u0026thinsp;\u0026plusmn;\u0026thinsp;4.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.696\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.490\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRVD3, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e51.80\u0026thinsp;\u0026plusmn;\u0026thinsp;5.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e52.41\u0026thinsp;\u0026plusmn;\u0026thinsp;5.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e51.09\u0026thinsp;\u0026plusmn;\u0026thinsp;4.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.891\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.378\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFAC, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44.80\u0026thinsp;\u0026plusmn;\u0026thinsp;5.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44.82\u0026thinsp;\u0026plusmn;\u0026thinsp;6.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44.78\u0026thinsp;\u0026plusmn;\u0026thinsp;5.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.983\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.443\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTV s\u0026prime;/SPAP ratio\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.738\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.464\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTAPSE/SPAP, mm/mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.681\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.499\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVC, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10.38\u0026thinsp;\u0026plusmn;\u0026thinsp;3.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.59\u0026thinsp;\u0026plusmn;\u0026thinsp;2.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.30\u0026thinsp;\u0026plusmn;\u0026thinsp;3.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-2.036\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.047\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRVGLS, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.53\u0026thinsp;\u0026plusmn;\u0026thinsp;2.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21.47\u0026thinsp;\u0026plusmn;\u0026thinsp;2.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21.60\u0026thinsp;\u0026plusmn;\u0026thinsp;3.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.162\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.872\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFWLS, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25.41\u0026thinsp;\u0026plusmn;\u0026thinsp;4.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.79\u0026thinsp;\u0026plusmn;\u0026thinsp;4.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24.97\u0026thinsp;\u0026plusmn;\u0026thinsp;4.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.604\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.549\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFWLS-base, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34.33\u0026thinsp;\u0026plusmn;\u0026thinsp;8.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.36\u0026thinsp;\u0026plusmn;\u0026thinsp;9.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e35.48\u0026thinsp;\u0026plusmn;\u0026thinsp;7.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.874\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.386\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFWLS-mid, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.22\u0026thinsp;\u0026plusmn;\u0026thinsp;8.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26.85\u0026thinsp;\u0026plusmn;\u0026thinsp;8.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.65\u0026thinsp;\u0026plusmn;\u0026thinsp;8.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.319\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.751\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFWLS-apex, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.00 (17.25, 26.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.00 (18.00, 26.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.00 (16.50, 27.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eZ=-0.039\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.969\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVSLS-base, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.62\u0026thinsp;\u0026plusmn;\u0026thinsp;7.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.14\u0026thinsp;\u0026plusmn;\u0026thinsp;6.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23.17\u0026thinsp;\u0026plusmn;\u0026thinsp;8.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.479\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.634\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVSLS-mid, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18.69\u0026thinsp;\u0026plusmn;\u0026thinsp;5.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.46\u0026thinsp;\u0026plusmn;\u0026thinsp;5.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.13\u0026thinsp;\u0026plusmn;\u0026thinsp;4.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.921\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.061\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVSLS-apex, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.21\u0026thinsp;\u0026plusmn;\u0026thinsp;4.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16.39\u0026thinsp;\u0026plusmn;\u0026thinsp;5.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13.83\u0026thinsp;\u0026plusmn;\u0026thinsp;4.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.860\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.069\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eLeft heart parameters\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eE (cm/s)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.76\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.331\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.190\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA (cm/s)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.040\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.304\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMV e\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.141\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.889\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMV a\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.035\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.306\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eE/e\u0026prime; ratio\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.28\u0026thinsp;\u0026plusmn;\u0026thinsp;1.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.42\u0026thinsp;\u0026plusmn;\u0026thinsp;1.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.13\u0026thinsp;\u0026plusmn;\u0026thinsp;1.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.689\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.494\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLVEF, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64.00\u0026thinsp;\u0026plusmn;\u0026thinsp;3.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e64.59\u0026thinsp;\u0026plusmn;\u0026thinsp;3.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e63.30\u0026thinsp;\u0026plusmn;\u0026thinsp;3.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.296\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.201\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCO, L/min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.980\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.332\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eAMS, acute mountain sickness; BMI, body mass index; BSA, body surface area; DBP, diastolic blood pressure; HR, heart rate; SBP, systolic blood pressure; SpO₂, oxygen saturation; CO, cardiac output; FAC, fractional area change; IVC, inferior vena cava; LVEF, left ventricular ejection fraction; mPAP, mean pulmonary arterial pressure; PVR, pulmonary vascular resistance; RVD1/2/3, right ventricular basal/mid-cavity/longitudinal diameter; SPAP, systolic pulmonary arterial pressure; TAPSE, tricuspid annular plane systolic excursion; TRV, tricuspid regurgitation velocity; TV s\u0026prime;/e\u0026prime;/a\u0026prime;, tricuspid annular peak systolic/early diastolic/late diastolic velocity.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eExercise Stress Echocardiography Findings\u003c/p\u003e \u003cp\u003eAt rest, no significant differences were observed between the AMS and non-AMS groups in key echocardiographic parameters, including SPAP, mPAP, TV s\u0026prime;, and FAC (all p\u0026thinsp;\u0026gt;\u0026thinsp;0.05), except for IVC diameter, which was significantly smaller in the non-AMS group (p\u0026thinsp;=\u0026thinsp;0.047) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAt peak exercise, although exercise duration (p\u0026thinsp;=\u0026thinsp;0.062) and peak heart rate (p\u0026thinsp;=\u0026thinsp;0.682) were comparable between groups, the AMS group achieved a significantly lower workload (p\u0026thinsp;=\u0026thinsp;0.015). No significant intergroup differences were observed in heart rate, systolic/diastolic blood pressure, oxygen saturation, TAPSE, FAC, RV global and regional longitudinal strain parameters, or left heart parameters including E, A, E/e\u0026prime; ratio, LVEF, and CO (all p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). In contrast, the AMS group demonstrated a markedly exaggerated pulmonary vascular response, characterized by significantly higher values in TRV (p\u0026thinsp;=\u0026thinsp;0.001), SPAP (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), mPAP (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), PVR (p\u0026thinsp;=\u0026thinsp;0.001), IVC diameter (p\u0026thinsp;=\u0026thinsp;0.018), and mPAP/CO slope (p\u0026thinsp;=\u0026thinsp;0.022), along with a greater number of subjects exhibiting B-lines (\u0026ge;\u0026thinsp;1) during ESE (p\u0026thinsp;=\u0026thinsp;0.035). Conversely, the TV s\u0026prime;/SPAP ratio (p\u0026thinsp;=\u0026thinsp;0.003) and TAPSE/SPAP ratio (p\u0026thinsp;=\u0026thinsp;0.017) were significantly lower in the AMS group (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eExercise testing results and measures at 3600 m.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003ePEAK\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eall\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003enon-AMS N\u0026thinsp;=\u0026thinsp;27\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAMS N\u0026thinsp;=\u0026thinsp;23\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003et/z/χ\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eBasic characteristics\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHR, b/m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e144.08\u0026thinsp;\u0026plusmn;\u0026thinsp;13.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e143.33\u0026thinsp;\u0026plusmn;\u0026thinsp;13.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e144.96\u0026thinsp;\u0026plusmn;\u0026thinsp;14.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.412\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.682\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSBP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e160.87\u0026thinsp;\u0026plusmn;\u0026thinsp;21.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e159.98\u0026thinsp;\u0026plusmn;\u0026thinsp;23.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e161.91\u0026thinsp;\u0026plusmn;\u0026thinsp;18.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.320\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.750\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDBP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e89.86\u0026thinsp;\u0026plusmn;\u0026thinsp;14.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e90.23\u0026thinsp;\u0026plusmn;\u0026thinsp;17.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e89.43\u0026thinsp;\u0026plusmn;\u0026thinsp;10.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.199\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.843\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpO2, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e82.21\u0026thinsp;\u0026plusmn;\u0026thinsp;6.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e83.06\u0026thinsp;\u0026plusmn;\u0026thinsp;6.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e81.39\u0026thinsp;\u0026plusmn;\u0026thinsp;5.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.197\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.845\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eExercise duration (min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.96\u0026thinsp;\u0026plusmn;\u0026thinsp;1.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.30\u0026thinsp;\u0026plusmn;\u0026thinsp;1.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.911\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.062\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLoad (Watt)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e106.00\u0026thinsp;\u0026plusmn;\u0026thinsp;19.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e112.04\u0026thinsp;\u0026plusmn;\u0026thinsp;18.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e98.91\u0026thinsp;\u0026plusmn;\u0026thinsp;17.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;2.529\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eRight heart and pulmonary circulation parameters\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTRV, m/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-3.479\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTV s\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.761\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.085\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTV e\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.077\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.287\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTV a\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.586\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.561\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTAPSE, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.69\u0026thinsp;\u0026plusmn;\u0026thinsp;3.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26.24\u0026thinsp;\u0026plusmn;\u0026thinsp;2.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.22\u0026thinsp;\u0026plusmn;\u0026thinsp;3.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.125\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.266\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSPAP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50.47\u0026thinsp;\u0026plusmn;\u0026thinsp;9.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e46.71\u0026thinsp;\u0026plusmn;\u0026thinsp;8.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e54.88\u0026thinsp;\u0026plusmn;\u0026thinsp;7.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-3.506\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emPAP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.28\u0026thinsp;\u0026plusmn;\u0026thinsp;5.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28.03\u0026thinsp;\u0026plusmn;\u0026thinsp;5.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32.93\u0026thinsp;\u0026plusmn;\u0026thinsp;4.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-3.506\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePVR, WU\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-3.450\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRVD1, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e32.38\u0026thinsp;\u0026plusmn;\u0026thinsp;4.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.34\u0026thinsp;\u0026plusmn;\u0026thinsp;3.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e33.61\u0026thinsp;\u0026plusmn;\u0026thinsp;5.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.851\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.073\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRVD2, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31.16\u0026thinsp;\u0026plusmn;\u0026thinsp;4.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.41\u0026thinsp;\u0026plusmn;\u0026thinsp;2.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32.04\u0026thinsp;\u0026plusmn;\u0026thinsp;6.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.196\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.241\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRVD3, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52.40\u0026thinsp;\u0026plusmn;\u0026thinsp;5.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e52.30\u0026thinsp;\u0026plusmn;\u0026thinsp;4.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e52.52\u0026thinsp;\u0026plusmn;\u0026thinsp;5.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.147\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.883\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFAC, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e55.66\u0026thinsp;\u0026plusmn;\u0026thinsp;5.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57.03\u0026thinsp;\u0026plusmn;\u0026thinsp;5.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e54.04\u0026thinsp;\u0026plusmn;\u0026thinsp;5.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.834\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.073\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTV s\u0026prime;/SPAP ratio\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;3.138\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTAPSE/SPAP, mm/mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;2.477\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.017\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVC, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13.74\u0026thinsp;\u0026plusmn;\u0026thinsp;3.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.78\u0026thinsp;\u0026plusmn;\u0026thinsp;2.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.87\u0026thinsp;\u0026plusmn;\u0026thinsp;3.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-2.454\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.018\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRVGLS, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.41\u0026thinsp;\u0026plusmn;\u0026thinsp;3.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.91\u0026thinsp;\u0026plusmn;\u0026thinsp;4.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.81\u0026thinsp;\u0026plusmn;\u0026thinsp;3.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.998\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.323\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFWLS, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25.64\u0026thinsp;\u0026plusmn;\u0026thinsp;6.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26.98\u0026thinsp;\u0026plusmn;\u0026thinsp;7.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24.07\u0026thinsp;\u0026plusmn;\u0026thinsp;6.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.484\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.144\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFWLS-base, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40.11\u0026thinsp;\u0026plusmn;\u0026thinsp;9.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42.12\u0026thinsp;\u0026plusmn;\u0026thinsp;10.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e37.75\u0026thinsp;\u0026plusmn;\u0026thinsp;8.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.606\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.115\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFWLS-mid, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25.88\u0026thinsp;\u0026plusmn;\u0026thinsp;9.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.34\u0026thinsp;\u0026plusmn;\u0026thinsp;9.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.52\u0026thinsp;\u0026plusmn;\u0026thinsp;10.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.439\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.663\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFWLS-apex, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17.50 (12.25, 25.75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18.00 (15.00, 26.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17.00 (12.00, 25.50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eZ=-0.283\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.777\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVSLS-base, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.49\u0026thinsp;\u0026plusmn;\u0026thinsp;7.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26.76\u0026thinsp;\u0026plusmn;\u0026thinsp;8.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.17\u0026thinsp;\u0026plusmn;\u0026thinsp;6.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.262\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.795\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVSLS-mid, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.99\u0026thinsp;\u0026plusmn;\u0026thinsp;5.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.68\u0026thinsp;\u0026plusmn;\u0026thinsp;5.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.17\u0026thinsp;\u0026plusmn;\u0026thinsp;4.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.014\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.315\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVSLS-apex, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.52\u0026thinsp;\u0026plusmn;\u0026thinsp;8.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.27\u0026thinsp;\u0026plusmn;\u0026thinsp;8.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.65\u0026thinsp;\u0026plusmn;\u0026thinsp;8.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.637\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.527\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eRV and pulmonary reserve\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emPAP/CO slope, mmHg /L/min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.70\u0026thinsp;\u0026plusmn;\u0026thinsp;1.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.97\u0026thinsp;\u0026plusmn;\u0026thinsp;1.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.17\u0026thinsp;\u0026plusmn;\u0026thinsp;1.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;2.364\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.022\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eΔTAPSE, mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.79\u0026thinsp;\u0026plusmn;\u0026thinsp;2.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.29\u0026thinsp;\u0026plusmn;\u0026thinsp;3.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.77\u0026thinsp;\u0026plusmn;\u0026thinsp;2.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.033\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.974\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eΔFAC, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10.86\u0026thinsp;\u0026plusmn;\u0026thinsp;4.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.22\u0026thinsp;\u0026plusmn;\u0026thinsp;5.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.26\u0026thinsp;\u0026plusmn;\u0026thinsp;3.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-2.200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.033\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eΔTV s\u0026prime;, m/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-2.856\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eΔSPAP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17.39\u0026thinsp;\u0026plusmn;\u0026thinsp;7.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.21\u0026thinsp;\u0026plusmn;\u0026thinsp;6.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.42\u0026thinsp;\u0026plusmn;\u0026thinsp;8.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;2.516\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eΔmPAP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10.42\u0026thinsp;\u0026plusmn;\u0026thinsp;4.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.89\u0026thinsp;\u0026plusmn;\u0026thinsp;3.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12.25\u0026thinsp;\u0026plusmn;\u0026thinsp;4.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;2.531\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDelta B-line (\u0026ge;\u0026thinsp;1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (18%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7(30%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.462\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.035\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eΔPVR, WU\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;2.681\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.010\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eLeft heart parameters\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eE (cm/s)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.401\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.168\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA (cm/s)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-0.093\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.926\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMV e\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-1.977\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.054\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMV a\u0026prime;,cm/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et=-2.410\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.020\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eE/e\u0026prime; ratio\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.87\u0026thinsp;\u0026plusmn;\u0026thinsp;1.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.21\u0026thinsp;\u0026plusmn;\u0026thinsp;1.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.47\u0026thinsp;\u0026plusmn;\u0026thinsp;1.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.730\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.090\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLVEF, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e76.75\u0026thinsp;\u0026plusmn;\u0026thinsp;3.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e76.79\u0026thinsp;\u0026plusmn;\u0026thinsp;3.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e76.70\u0026thinsp;\u0026plusmn;\u0026thinsp;3.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.095\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.924\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCO, L/min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.34\u0026thinsp;\u0026plusmn;\u0026thinsp;1.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.42\u0026thinsp;\u0026plusmn;\u0026thinsp;1.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.25\u0026thinsp;\u0026plusmn;\u0026thinsp;1.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;0.462\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.646\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eΔ, change from rest to peak exercise; B-line, ultrasound lung comet-tail artifact (\u0026ge;\u0026thinsp;1 defined as abnormal). Other abbreviations are as defined in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAnalysis of functional reserve revealed that the AMS group demonstrated significantly smaller increases in ΔTV s\u0026prime; (p\u0026thinsp;=\u0026thinsp;0.006) and ΔFAC (p\u0026thinsp;=\u0026thinsp;0.033), while ΔTAPSE did not differ significantly between groups (p\u0026thinsp;=\u0026thinsp;0.974) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAMS Prediction Model\u003c/p\u003e \u003cp\u003eBased on univariable logistic regression, the following variables were significantly associated with AMS and were included as candidate predictors: SPAP at rest, TV s\u0026prime; at rest, TAPSE/SPAP at rest, IVC at peak exercise, mPAP at peak exercise, PVR at peak exercise, SPAP at peak exercise, and TR at peak exercise, mPAP/CO slope, ΔPVR, ΔTV s\u0026prime; (all P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) (Supplemental Table\u0026nbsp;1). These variables were entered into a multivariable stepwise logistic regression model with entry and retention set at P\u0026thinsp;\u0026lt;\u0026thinsp;0.05. The final model identified three independent predictors of AMS: ΔPVR (P\u0026thinsp;=\u0026thinsp;0.005), IVC-peak (P\u0026thinsp;=\u0026thinsp;0.024), and ΔTV s\u0026prime; (P\u0026thinsp;=\u0026thinsp;0.047) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMultivariate logistic regression analysis of the predictors of AMS\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eβ\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eS. E\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eZ\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eOR (95%CI)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntercept\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-5.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.01 (0.00\u0026thinsp;~\u0026thinsp;0.48)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eΔTV s\u0026prime;, m/s\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-1.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.047\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.81 (0.66\u0026thinsp;~\u0026thinsp;0.99)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eΔPVR, WU\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.07 (1.02\u0026thinsp;~\u0026thinsp;1.13)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVC-peak,mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.024\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.35 (1.04\u0026thinsp;~\u0026thinsp;1.75)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eβ, regression coefficient; S.E., standard error; OR, odds ratio; CI, confidence interval. Variables: ΔTV s\u0026prime;, change in tricuspid annular peak systolic velocity from rest to peak exercise; ΔPVR, change in pulmonary vascular resistance from rest to peak exercise; IVC-peak, inferior vena cava diameter at peak exercise.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThese three indicators were subsequently integrated to construct a new predictive nomogram model (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA), which demonstrated superior predictive performance compared to any individual indicator (nomogram: AUC, 0.865 [95% CI, 0.760\u0026ndash;0.969]; ΔPVR: cutoff, 0.375, AUC, 0.763 [95% CI, 0.626\u0026ndash;0.900]; IVC-peak: cutoff, 13.5, AUC, 0.680 [95% CI, 0.527\u0026ndash;0.834]; ΔTV s\u0026prime;: cutoff, 0.045, AUC, 0.713 [95% CI, 0.565\u0026ndash;0.860]; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB). The nomogram model achieved a sensitivity of 0.783 (95% CI, 0.614\u0026ndash;0.951) and a specificity of 0.889 (95% CI, 0.770\u0026ndash;1.000).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eBootstrap internal validation (1,000 resamples) confirmed good calibration of the model, as shown by the close alignment between predicted probabilities and actual AMS incidence in the calibration curve (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eC). DCA indicated favorable net benefit across a wide range of threshold probabilities (Supplemental Fig.\u0026nbsp;1). Furthermore, CIC (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eD) illustrated the relationship between the number of individuals classified as high-risk (solid red line) and the number of true events (dashed blue line). Close alignment of the two curves at lower risk thresholds reflected high clinical predictive performance; increasing divergence suggested reduced sensitivity at higher thresholds. Both the individual predictors (ΔPVR, IVC-peak, ΔTV s\u0026prime;; Supplemental Figs.\u0026nbsp;2A,2B,2C) and the integrated nomogram exhibited excellent predictive value within an optimal risk-threshold range, with the nomogram demonstrating particularly robust performance (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eD). This combined approach effectively enhances clinical decision-making for AMS risk assessment.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study provides unique insights into the compensatory insufficiency of the pulmonary vasculature and RV systolic function in AMS. We demonstrate that despite comparable resting RV and pulmonary vascular function between AMS and non-AMS subjects, AMS patients exhibit impaired pulmonary vascular reserve, diminished RV contractile reserve, increased B-lines and IVC enlargement during exercise. The nomogram incorporating IVC-peak, ΔTV s\u0026prime;, and ΔPVR demonstrated excellent predictive performance, providing an objective tool for early identification of high-risk AMS individuals and guiding decisions regarding high-altitude exposure.\u003c/p\u003e \u003cp\u003eComparison with Previous Studies\u003c/p\u003e \u003cp\u003eExcessive PAP elevation induced by hypoxia represents a fundamental pathophysiological mechanism in HAPE. Previous investigations in HAPE-susceptible individuals have demonstrated significantly greater PAP increases and elevated PVR during hypoxic exercise compared to healthy controls, who typically show PVR reduction\u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e, findings consistent with low-altitude observations\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e and reports in Chronic Mountain Sickness (CMS) patients at high altitude\u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e. In our study, both AMS and non-AMS subjects exhibited increased PVR and PAP during exercise, but the AMS group demonstrated significantly greater increases. This response during high-altitude exercise may stem from impaired hypoxic ventilatory response in AMS individuals, leading to enhanced hypoxic pulmonary vasoconstriction and ventilation/perfusion mismatch \u0026ndash; key mechanisms underlying the elevated PAP and PVR observed in AMS subjects compared to non-AMS\u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e. This pathophysiological process likely involves imbalance between vasoconstrictive and vasodilatory forces, potentially combined with reduced pulmonary vasodilatory activity in AMS individuals\u003csup\u003e[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eWe hypothesize that high-altitude hypoxia compromises pulmonary vascular capacitance. While non-AMS individuals at low altitude can compensate for exercise-induced blood flow increases through pulmonary vasodilation and PVR reduction\u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e, AMS subjects at high altitude experience more substantial pulmonary vasodilation limitations, resulting in markedly greater PAP and PVR elevations during exercise. Although capillary distension to reduce resistance may represent an adaptive exercise response, this mechanism becomes limited by hypoxemia from altered diffusion/perfusion relationships\u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. The elevated mPAP/CO slope in AMS subjects further indicates reduced pulmonary vascular distensibility, leading to disproportionate PAP elevations with increasing CO.\u003c/p\u003e \u003cp\u003eElevated PAP demands enhanced RV contractility. In pulmonary hypertension (PH) patients, survival depends on RV adaptation to persistent high PAP. Previous studies indicate that PH patients with compromised RV contractile reserve have a poorer prognosis\u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. RV contractile reserve is crucial for maintaining effective RV-pulmonary artery coupling and stability during exercise stress, with its reduction serving as an early marker of RV compensatory insufficiency \u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. Pratali et al. demonstrated significant TV s\u0026prime; increases in healthy subjects but minimal changes in CMS patients, indicating reduced RV contractility reserve\u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e. Similarly, our study revealed smaller TV s\u0026prime; and FAC increases in the AMS group compared to non-AMS group, suggesting less efficient functional compensation despite preserved RV systolic reserve, a pattern distinct from low-altitude observations\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. Various indices of RV contractile reserve present distinct advantages and limitations. While TAPSE and TV s\u0026prime; primarily assess longitudinal motion, FAC evaluates both longitudinal and radial contraction components. LS offers advantages in detecting subclinical RV dysfunction earlier than traditional parameters, though post-exercise image tracking presents technical challenges in some subjects\u003csup\u003e[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]\u003c/sup\u003e. Our findings indicate that although RV function was temporarily maintained through enhanced longitudinal contraction or regional compensation\u003csup\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e, the reduced ΔFAC and ΔTV s\u0026prime; consistently demonstrated decreased contractile reserve in AMS compared to non-AMS. Despite higher PAP and consequent RV afterload in AMS subjects, coupling parameters including TV s\u0026prime;/SPAP and TAPSE/SPAP ratios remained within normal ranges, though AMS subjects exhibited lower coupling efficiency compared to non-AMS. This coupling reduction likely originates from abnormal RV-pulmonary artery interaction secondary to elevated SPAP \u003csup\u003e[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/sup\u003e. While previous investigations, including Forbes et al. reported maintained RV-pulmonary artery coupling during hypoxic exercise in healthy individuals\u003csup\u003e[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e, our results demonstrate subtle but clinically relevant decreases in AMS subjects, indicating impaired RV-pulmonary artery coupling and diminished capacity to cope with physiological stressors like exercise.\u003c/p\u003e \u003cp\u003eIn response to high RV afterload, compensatory mechanisms maintain CO by elevating HR and venous return (preload), resulting in increased right atrial pressure and IVC diameter\u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/sup\u003e. Both at low and high altitudes, the AMS group exhibited wider IVC during exercise despite comparable HR. This finding represents an early compensatory response to elevated right heart pressure and serves as a key imaging marker of venous congestion in AMS\u003csup\u003e[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]\u003c/sup\u003e.Although B-lines were not retained as an ultimate independent predictor in the multivariate model, the increased B-lines observed in the AMS group reflect subclinical pulmonary interstitial edema resulting from exaggerated pulmonary hypertension during exercise\u003csup\u003e[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]\u003c/sup\u003e. Collectively, the concurrent enlargement of IVC and increased B-lines delineate a hemodynamic continuum of right heart load and pulmonary fluid accumulation in AMS-susceptible individuals under high-altitude exertion.\u003c/p\u003e\n\u003ch3\u003eClinical Implications\u003c/h3\u003e\n\u003cp\u003eWhile previous investigations have explored various cardiovascular AMS predictors including SpO2\u003csup\u003e[\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]\u003c/sup\u003e, pulse pressure, effective arterial elastance\u003csup\u003e[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/sup\u003e, and mitral annular displacement \u003csup\u003e[\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]\u003c/sup\u003e, our prior work specifically identified low-altitude parameters including peak exercise PVR, IVC diameter, and B-line counts as AMS predictors\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. However, studies predicting AMS development in individuals already at high altitude remain limited. Current evidence indicates that subjects exhibiting greater SPO\u003csub\u003e2\u003c/sub\u003e decreases during high-altitude exercise demonstrate increased AMS susceptibility, though this observation was documented on day 7 post-exposure\u003csup\u003e[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe distinctive feature of our study lies in its focus on physiological stress responses during the initial 6 hours of high-altitude exposure. Our comprehensive quantification of echocardiographic indices during rest and exercise under real-world high-altitude conditions not only enhances understanding of cardiopulmonary adaptive differences in AMS subjects but also establishes ESE-derived parameters as predictive indicators for next-day AMS occurrence. This provides a clinically actionable risk stratification tool that may prevent progression to severe high-altitude illnesses. The rapid, cost-effective ESE protocol we propose completes risk assessment within 15 minutes, making it particularly suitable for on-site screening before further ascent. This tool offers potential value for all mountaineers and could guide personalized interventions including graded ascent, pre-acclimatization training, or targeted pharmacological prevention.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eLimitations\u003c/h2\u003e \u003cp\u003eSeveral limitations warrant consideration. First, although the sample size was relatively modest, all subjects were selected using strict inclusion and exclusion criteria. Second, excluding subjects without measurable tricuspid regurgitation may limit generalizability to this specific population. Third, we utilized non-invasive rather than invasive hemodynamic assessment for pulmonary hemodynamics, though the latter remains the gold standard but presents substantial ethical and logistical challenges. Finally, the generalizability of our findings beyond healthy Han Chinese adults remains uncertain for other ethnicities, age groups, and individuals with comorbidities, as well as for the highly variable individual physiological responses to high-altitude exposure.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eTo our knowledge, this is the first study to comprehensively evaluate biventricular function and pulmonary circulation during rest and exercise within 6 hours of high-altitude exposure in individuals who subsequently developed AMS. Our findings demonstrate that AMS subjects exhibit a distinct phenotype characterized by elevated PAP and PVR during exercise, accompanied by decreased pulmonary vascular reserve, reduced RV contractile reserve, mildly diminished exercise capacity, and evidence of intravascular (IVC enlargement) and pulmonary extravascular (B-lines) congestion. LV systolic and diastolic function remained preserved in these subjects. Importantly, ESE effectively detected these early alterations in the right heart-pulmonary circulatory system and demonstrated predictive value for identifying AMS-susceptible individuals. Future studies should focus on validating the proposed predictive thresholds and assessing their value in guiding ESE-driven preventive therapeutic interventions.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"662\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAbbreviation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFull Term\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAMS\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAcute Mountain Sickness\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAUC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eArea Under the Curve\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eConfidence Interval\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCMS\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eChronic Mountain Sickness\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eCIC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eclinical impact curves\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCO\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCardiac Output\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eDBP\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eDiastolic Blood Pressure\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eDCA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eDecision curve analysis\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eESE\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eExercise Stress Echocardiography\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFAC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFractional Area Change\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFWLS\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFree Wall Longitudinal Strain\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eHACE\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eHigh-Altitude Cerebral Edema\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eHAPE\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eHigh-Altitude Pulmonary Edema\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eHR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eHeart Rate\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eIVC\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eInferior Vena Cava\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eIVSLS\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eInterventricular Septum Longitudinal Strain\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLLS\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eLake Louise Score\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLS\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eLongitudinal Strain\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLVEF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eLeft Ventricular Ejection Fraction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003emPAP\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eMean Pulmonary Artery Pressure\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eOdds Ratio\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePAP\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ePulmonary Arterial Pressure\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePAWP\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ePulmonary Artery Wedge Pressure\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePH\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ePulmonary Hypertension\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePVR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ePulmonary Vascular Resistance\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eRV\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eRight Ventricular\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eRVD\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eRight Ventricular Diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eRVGLS\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eRight Ventricular Global Longitudinal Strain\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSBP\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSystolic Blood Pressure\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSpO2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eOxygen Saturation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSPAP\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSystolic Pulmonary Artery Pressure\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eTAPSE\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTricuspid Annular Plane Systolic Excursion\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eTRV\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTricuspid Regurgitation Velocity\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eTV s\u0026prime;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTricuspid Annular Peak Systolic Velocity\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026Delta;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003echange from rest to peak exercise\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate.\u003c/p\u003e\n\u003cp\u003eThe study protocol was approved by the Institutional Research and Ethical Committees of Sichuan Provincial People′s Hospital (Approval No. 2023-436). All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from all individual participants included in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent for publication was obtained from all participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author (Yi Wang) on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Sichuan Provincial Medical Research Project (Grant Number S2024007 to Yi Wang).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors′ contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eYun Xu: Formal analysis, Investigation, Writing - Original Draft. \u0026nbsp;Sijia Wang: Formal analysis, Investigation, Writing - Original Draft. \u0026nbsp;Yong Jing: Data Curation. Qingfeng Zhang: Methodology, Resources, Validation. \u0026nbsp;Kai Wang: Software, Visualization. \u0026nbsp;Yan Deng: Investigation. \u0026nbsp;JingXue Fan: Investigation. \u0026nbsp;Lixue Yin: Conceptualization, Supervision, Project administration, Writing - Review \u0026amp; Editing. \u0026nbsp;Yi Wang: Conceptualization, Supervision, Funding acquisition, Writing - Review \u0026amp; Editing. \u0026nbsp;All authors reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ewe would like to thank the National Emergency Rescue Team for logistical support, Dr. Yan Yang for imaging assistance, and Nurse Pei Fu for participant recruitment.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eImray C, Wright A, Subudhi A, et al. Acute mountain sickness: Pathophysiology, prevention, and treatment[J]. 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Br J Sports Med. 2023;57(14):906\u0026ndash;13. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1136/bjsports-2022-106211\u003c/span\u003e\u003cspan address=\"10.1136/bjsports-2022-106211\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Acute Mountain Sickness, RV Function, Pulmonary Artery Pressure, Pulmonary Vascular Resistance, Exercise Stress Echocardiography","lastPublishedDoi":"10.21203/rs.3.rs-8777421/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8777421/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBACKGROUND\u003c/h2\u003e \u003cp\u003eEarly identification of individuals vulnerable to acute mountain sickness (AMS) is clinically challenging. We hypothesized that exercise stress echocardiography (ESE), conducted shortly after high-altitude arrival, could reveal distinctive right ventricular (RV) and pulmonary vascular responses predictive of AMS development.\u003c/p\u003e\u003ch2\u003eMETHODS\u003c/h2\u003e \u003cp\u003eWithin 6 hours of arrival, 50 healthy lowland residents underwent ESE. Key measures included systolic pulmonary artery pressure (SPAP), pulmonary vascular resistance (PVR), tricuspid annular peak systolic velocity (TV s\u0026prime;), RV fractional area change (FAC), inferior vena cava (IVC) diameter, and mean PAP/cardiac output (CO) slope. AMS was assessed the next morning using the Lake Louise Score.\u003c/p\u003e\u003ch2\u003eRESULTS\u003c/h2\u003e \u003cp\u003eOf the participants, 23 (46%) developed AMS and 27 (54%) did not (non-AMS group). At peak exercise, the AMS group exhibited significantly higher SPAP (54.88\u0026thinsp;\u0026plusmn;\u0026thinsp;7.89 vs. 46.71\u0026thinsp;\u0026plusmn;\u0026thinsp;8.48 mmHg, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and PVR (2.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26 vs. 2.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 WU, p\u0026thinsp;=\u0026thinsp;0.001), accompanied by greater increases from rest (denoted as Δ) in SPAP (20.42\u0026thinsp;\u0026plusmn;\u0026thinsp;8.13 vs. 13.21\u0026thinsp;\u0026plusmn;\u0026thinsp;6.22 mmHg, p\u0026thinsp;=\u0026thinsp;0.015) and PVR (0.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 vs. 0.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 WU, p\u0026thinsp;=\u0026thinsp;0.010). Conversely, the AMS group demonstrated impaired RV contractile reserve, reflected by smaller in ΔTV s\u0026prime; (0.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 vs. 0.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 m/s, p\u0026thinsp;=\u0026thinsp;0.006) and ΔFAC (8.26\u0026thinsp;\u0026plusmn;\u0026thinsp;3.89 vs. 12.22\u0026thinsp;\u0026plusmn;\u0026thinsp;5.35%, p\u0026thinsp;=\u0026thinsp;0.033). IVC diameter was larger in the AMS group both at rest and during peak exercise (p\u0026thinsp;=\u0026thinsp;0.047 and p\u0026thinsp;=\u0026thinsp;0.018). A nomogram incorporating peak IVC diameter, ΔPVR, and ΔTV s\u0026prime; predicted AMS with an area under the curve (AUC) of 0.865 and an accuracy of 84.0%.\u003c/p\u003e\u003ch2\u003eCONCLUSION\u003c/h2\u003e \u003cp\u003eESE detects early alterations in RV function, IVC dynamics, and pulmonary circulation in individuals susceptible to AMS within hours of high-altitude exposure. A model based on IVC, ΔPVR, and ΔTV s\u0026prime; offers a practical tool for early AMS risk stratification.\u003c/p\u003e\u003ch2\u003eClinical trial number:\u003c/h2\u003e \u003cp\u003enot applicable\u003c/p\u003e","manuscriptTitle":"Early detection of acute mountain sickness after high-altitude exposure","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-10 17:12:40","doi":"10.21203/rs.3.rs-8777421/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-22T07:29:36+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-30T03:17:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"249580365253222532861577278807932986082","date":"2026-03-19T14:12:35+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-13T22:48:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"6553793712742292840734049911690545035","date":"2026-03-13T22:00:21+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-05T10:19:23+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-02-09T10:10:42+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-06T11:29:25+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-06T11:26:54+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pulmonary Medicine","date":"2026-02-03T14:23:33+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"611f5fbb-3d53-4822-b9f1-3a564591f000","owner":[],"postedDate":"March 10th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2026-05-08T07:08:10+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-10 17:12:40","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8777421","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8777421","identity":"rs-8777421","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}