Ultrasonography evaluation of the inferior vena cava collapsibility index and the superior vena cava distensibility index for predicting hypotension during general anesthesia in atrial fibrillation patients：a prospective observational study

Ultrasonography evaluation of the inferior vena cava collapsibility index and the superior vena cava distensibility index for predicting hypotension during general anesthesia in atrial fibrillation patients：a prospective observational study | 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 Ultrasonography evaluation of the inferior vena cava collapsibility index and the superior vena cava distensibility index for predicting hypotension during general anesthesia in atrial fibrillation patients：a prospective observational study Xiaomei Li, Guangsui Yang, Suwen Hao, Changhua Zhu, Haijian Liu, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6444922/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 01 Sep, 2025 Read the published version in BMC Anesthesiology → Version 1 posted 14 You are reading this latest preprint version Abstract Background: Atrial fibrillation (AF) is a prevalent arrhythmia, the ineffective contraction of the atria leads to a decrease in effective cardiac output. AF patients are prone to hypotension during anesthesia, especially in the early stages of general anesthesia. We explored whether the inferior vena cava collapsibility index (IVCCI) or the superior vena cava distensibility index (SVCDI) could predict the occurrence of post-induction hypotension (PIH) and early intraoperative hypotension (eIOH) in AF patients. Methods: A total of 77 AF patients undergoing left atrial appendage occlusion under general anesthesia were included in this study. The inferior vena cava was measured before induction and the superior vena cava after induction. The main outcome was the ultrasound measurements of IVCCI and SVCDI in AF patients and theirassociation with hypotension during general anesthesia. Hypotension was classified as the mean arterial pressure (MAP) below 60 mmHg or more than 20% below the baseline level. The correlation between IVC-CI, SVC-DI and the percentage decrease in MAP was assessed. Receiver operating characteristic (ROC) curves of IVC-CI, SVC-DI were separately generated to predict PIH and eIOH. Logistic regression was employed to validate the risk factors for PIH and eIOH in AF patients. Results: AF patients who developed PIH had a significantly higher IVCCI (P<0.001) and developed eIOH had a significantly higher SVCDI (P<0.001). ROC curve analysis showed that IVCCI had an accuracy of 85% to predict PIH at a cut-off point more than 34.1% (P<0.001). SVCDI had an accuracy of 86% to predict eIOH at a cut-off point more than 17.8% (P<0.001). After adjusting for confounding variables, IVCCI was an independent predictor of PIH ( P <0.001), while SVCDI was an independent predictor of eIOH ( P 34.1% indicates a non-invasive predictor of PIH in AF patients; SVCDI>17.8% suggest a reliable predictor of eIOH in AF patients. Trial registration: This trial was registered on June 27, 2023 at the China Clinical Trial Center (http://www.chictr.org.cn; No. ChiCTR2300072846). IVC-CI SVC-DI atrial fibrillation post-induction hypotension early intraoperative hypotension Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Atrial fibrillation (AF) is one of the most common arrhythmias in adults, with a reported incidence and prevalence of 1.6% in China [1] . AF elevates the risk of ischemic stroke and systemic arterial embolism. In recent years, various open and percutaneous left atrial appendage occlusion devices have been developed, and some have shown comparable effectiveness to anticoagulants in preventing strokes in patients with AF [2] . Percutaneous left atrial appendage closure, commonly performed under general anesthesia to optimize procedural conditions through patient immobilization and prolonged transesophageal echocardiography (TEE), poses a significant risk of hypotension. This complication is particularly pronounced in elderly patients with pre-existing cardiovascular comorbidities. A decrease in arterial pressure during anesthesia induction can result in perioperative complications, such as acute kidney injury, heart failure, cerebral ischemia, and myocardial infarction [3-6] . Factors predicting hypotension include age, a higher American Society of Anesthesiologists (ASA) physical status, use of propofol, dosage of fentanyl, and importantly, volume status [7-8] . Patients with AF also face an increased risk of post-induction hypotension (PIH) or early intraoperative hypotension (eIOH) during general anesthesia. Recently recommended dynamic parameters for assessing volume status include ultrasound measurements of the inferior vena cava (IVC) diameter with respiration [9-10] . These parameters, such as the maximum diameter of the IVC (IVCmax) at the end of expiration and the collapsibility index (CI), have been suggested as rapid, noninvasive methods to predict anesthesia-related hypotension [11-12] . However, patients with AF lack atrial contraction support during left ventricular diastolic filling, which can lead to elevated left atrial pressure and necessitate greater volume management. Additionally, AF may compromise the utility of cardiopulmonary interaction-based volume status measurements, such as stroke volume variation [13] . The effectiveness of IVC variability as an indicator in patients with AF has yet to be explored. This study aims to explore the clinical value of the inferior vena cava collapsibility index and the superior vena cava distensibility index in predicting the occurrence of PIH and eIOH events in atrial fibrillation patients. Methods Patients We selected 77 patients with atrial fibrillation (aged 65–85) who underwent left atrial appendage occlusion under general anesthesia at Shanghai Zhoupu Hospital between June 2022 and January 2023, based on sample size calculations. The study protocol was reviewed and approved by the Institutional Ethics Committee of Shanghai Zhoupu Hospital (Registration number:2022-C-027-E0) and conformed to the ethical standards for medical research involving human subjects, as laid out in the 1964 Declaration of Helsinki and its later amendments. Participants provided written informed consent prior to taking part in the study The trial was registered at http://www.chictr.org.cn (registration number:ChiCTR2300072846) on 27 June 2023. Our reporting adhered to the STROBE guidelines. Participants in this study were at least 65 years old, with a body mass index (BMI) ranging from 18 to 32 kg m - ², an American Society of Anesthesiologists (ASA) physical status of 2 to 3, and scheduled for left atrial appendage occlusion. The exclusion criteria were as follows: emergency surgery, sudden life-threatening changes in vital signs, elevated intra-abdominal pressure, expected airway or mental dysfunction, diseases of the autonomic nervous system, current use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, presence of an implantable pacemaker or cardioverter, peripheral vascular disease, serious cardiovascular conditions, unstable angina, and an ejection fraction (EF) of less than 40%. Materials and methods Upon entering the room, peripheral veins were opened, and lactated Ringer's solution was administered at a rate of 30 drops per minute, along with a pre-treatment of 0.05 mg kg -1 of midazolam. Patients were conscious, lying supine, and breathing spontaneously for at least five minutes before the examination. The maximum (IVCmax) and minimum (IVCmin) diameters of the inferior vena cava were measured using ultrasound during one spontaneous respiratory cycle in AF patients, as shown in Fig 1a. The collapsibility index of inferior vena cava (IVCCI) was calculated using the following equation: collapsibility index = (IVCmax-IVCmin)/IVCmax*100 [14] . The ultrasound measurement of the inferior vena cava was performed as follows: the patient was positioned supine without a pillow, with hands relaxed at the sides, following the method described by the American Society of Echocardiography [15] : The subxiphoid approach was used, with a phased-array probe from a Siemens Healthineers ACUSON SC2000 machine placed subxiphoid to display the four-chamber view. The probe was then rotated downward towards the spine, with the orientation marker pointing towards the patient's head, to show the inferior vena cava entering the right atrium and the hepatic veins joining the inferior vena cava. The diameter of the inferior vena cava was measured 2 cm from the right atrial entrance, IVCmax and IVCmin were measured by freezing the ultrasound image at end-expiration and end-inspiration respectively. Each site was measured three times, and the average was taken; measurements differing by more than 2 mm were excluded. After anesthesia induction, the maximum (SVCmax) and minimum (SVCmin) diameters of the superior vena cava were measured using a transesophageal ultrasound probe from a Siemens machine over one mechanical ventilation respiratory cycle in AF patients, as shown in Fig 1b. The distensibility index of superior vena cava (SVCDI) was calculated using the following equation: distensibility index = (SVCmax-SVCmin)/SVCmin*100 [16] . The transesophageal ultrasound measurement of the superior vena cava was performed as follows: after the patient was under general anesthesia and mechanically ventilated, the transesophageal ultrasound was adjusted to a depth of 10 cm based on the mid-esophageal bicaval view. This view clearly displayed the left atrium, right atrium, interatrial septum, superior vena cava, inferior vena cava, partial pulmonary veins, and their connections to the right atrium, from which SVCmax and SVCmin were obtained. Each site was measured three times, and the average was taken; measurements differing by more than 2 mm were excluded. The measurement process did not exceed 3 minutes, and the entire induction period did not exceed 5 minutes. All ultrasound measurements were performed by an experienced anesthesiologist who was blinded to the study. Arterial pressure was measured invasively using an arterial line catheter, which was inserted before anesthesia induction. Hemodynamic data were collected both before (baseline) and after induction. Post-induction hypotension (PIH) was defined by a decrease in mean arterial pressure (MAP) of more than 20% from baseline or any recorded period of MAP below 60 mmHg [17] . MAP is continuously monitored and recorded within the first 15 minutes after the start of surgery. Early intraoperative hypotension (eIOH) was defined as a MAP below 60 mmHg or a reduction of more than 20% from the baseline level within the first 15 minutes after skin incision [8] . Anesthesia induction involved a regimen of sufentanil (0.35 µg kg -1 ) and propofol (1.5 mg kg -1 ), followed by tracheal intubation facilitated by cisatracurium (1.5 mg kg -1 ). Anesthesia was maintained with 1.5 vol% inhaled sevoflurane in oxygen-enriched air and remifentanil continuously infused at 6 µg kg -1 h -1 . In cases of severe hypotension (MAP < 55 mmHg) or prolonged hypotension episodes (lasting ≥ 3 minutes) during the induction phase or early intraoperative period, intravenous ephedrine 6 mg or norepinephrine infusion at 200 µg h -1[18] . However, patients who experience severe hypotension requiring pharmacological intervention during the induction phase or early intraoperative period are excluded. Statistical analysis Sample size The sample size was calculated using PASS15.0 software, commonly utilized in clinical research. Based on a literature review, we used the following parameters: the sensitivity of the IVC to predict intraoperative hypotension is 80%, the specificity is 90%, α=0.05. The calculation indicated that 70 cases are needed for this study. To account for a potential dropout rate of 10%, 77 AF patients will be included. Data analysis Data were compiled and analyzed using Microsoft Excel, for statistical analyses, we employed StataMP16 and PRISM. Continuous variables are presented as means ± standard deviations if they are normally distributed, as confirmed by the Shapiro-Wilk W test. Non-normally distributed data are displayed as medians and interquartile ranges. For comparisons, we used Student's two-sample t-test and the Mann-Whitney U test. Categorical variables are shown as percentages and absolute case numbers. The χ 2 -test and Fisher's exact test were used for analyzing contingency tables as appropriate. Two-sided p-values are reported, with a significance threshold set at p <0.05. The pearson correlation coefficient ( r ) was utilized to evaluate the association between measurements and the percentage decrease in MAP from baseline after the induction of general anesthesia. ROC curve analysis was conducted to evaluate the predictive capability of the two ultrasound-derived parameters, IVCCI and SVCDI, for clinically significant of PIH and eIOH. The areas under the curves (AUCs) with 95% confidence intervals were computed. We compared the two ROC curves using the nonparametric method described by DeLong et al [19] . Optimal cutoff values were determined by the values that maximize the Youden index (sensitivity+specificity-1). Logistic regression was employed to validate the risk factors for PIH and eIOH in AF patients. Results A total of 77 AF patients were initially included in this analysis, however, 7 were subsequently excluded due to inadequately visualized IVC in 3 cases and missing data in 4 cases, as shown in Fig 2. Ultimately, 70 AF patients were analyzed. Thirty-four patients were male and 36 were female. Their mean age was 75.2 ± 6.3 years, mean BMI was 23.9 ± 3.2 kg m -2 . Fifteen patients were ASA 2, while 55 were ASA 3. Thirty-two patients developed PIH after induction, 21 patients developed eIOH after skin incision. When comparing AF patients who developed PIH and eIOH with those who did not, we found that there were no significant differences between the two groups as regards sex, BMI, ASA status, baseline MAP or HR. Significant differences were observed in the IVCmax and IVCCI, where AF patients with PIH had a significantly higher IVCCI ( P < 0.001) and a lower IVCmax ( P < 0.005) compared to those who did not. Similarly, patients with AF who developed eIOH, both IVCmax and SVCmax were significantly lower than in the normal blood pressure group, whereas IVCCI and SVCDI were significantly higher ( P < 0.001).The demographic characteristics of AF patients are summarized in Table 1. After anesthesia induction, the IVCmax showed a low-degree negative correlation with the percentage decrease in MAP ( r ＝−0.42, P < 0.001). On the other hand, the IVCCI exhibited a significant positive correlation with the decrease in MAP ( r ＝0.55, P < 0.001) (Fig.3a). During the early intraoperative period, IVCmax showed a low-degree negative correlation with the percentage decrease in MAP ( r ＝−0.48, P < 0.001), while IVCCI exhibited a low-degree positive correlation ( r ＝0.45, P < 0.001) (Fig. 3b). SVCmax demonstrated a significant negative correlation with the percentage decrease in MAP ( r ＝−0.54, P < 0.001), and SVCDI showed a significant positive correlation with the decrease in MAP ( r ＝−0.54, P < 0.001) (Fig. 3c). Table 1 Comparison of characteristics of AF patients with post-induction hypotension and early intraoperative hypotension Developed PIH Developed eIOH variables Yes( n =32) No( n =38) P Yes( n =21) Yes( n =21) P Age(years) 74.7 ± 5.5 75.6 ± 7.0 0.57 75.7 ± 5.7 75.0 ± 6.6 0.68 Sex 0.49 0.35 male 17（24%） 17（24%） 12（17%） 22（31%） female 15（22%） 21（30%） 9（13%） 27（39%） BMI（%） 0.45 0.04 18~23.99 Kg m -2 19（27%） 17（24%） 15（21%） 21（30%） 24~27.99 Kg m -2 8（12%） 16（23%） 5（8%） 19（27%） 28~32 Kg m -2 5（7%） 5（7%） 1（1%） 9（13%） ASA physical status 0.93 0.35 II 7（10%） 8（11%） 6（9%） 9（13%） III 25（36%） 30（43%） 15（21%） 15（21%） MAP（mmHg） 107.1 ± 13.8 103.0 ± 11.5 0.28 110.3 ± 15.0 103.6 ± 11.3 0.05 HR（per/min） 80.0 ± 21.1 74.1 ± 11.8 0.14 77.5 ± 14.4 76.5 ± 17.9 0.83 IVCmax(mm) 18.4 ± 3.3 21.2 ± 2.6 ＜0.001 17.5 ± 3.1 21.0 ± 2.7 ＜0.001 IVCCI(%) 40.9 ± 12.6 23.8 ± 8.9 ＜0.001 43.0± 10.1 26.8± 12.1 ＜0.001 SVCmax(mm) － － 15.3 ± 2.6 18.6 ± 2.4 ＜0.001 SVCDI(%) － － 26.6 ± 7.1 16.0 ± 7.4 ＜0.001 Values are mean ± SD, number of patients or number (%). BMI, body mass index; ASA, American Society of Anesthesiologists; MAP, mean artery pressure; HR, heart rate; IVCmax, maximum inferior vena cava diameter; IVCCI, collapsibility index of inferior vena cava; SVCmax, maximum superior vena cava diameter; SVCDI, distensibility index of superior vena cava; PIH, post-induction hypotension; eIOH, early intraoperative hypotension. The ROC curve analysis showed that AF patients with a AUROC of 95% confidence intervals was 0.77 ( P < 0.001) for IVCCI and 0.86 (P < 0.001) for IVCmax to predict PIH. The optimal threshold for IVCmax was 19.4 mm (sensitivity 72%, specificity 79%), while for IVCCI it was 34.1% (sensitivity 84%, specificity 92%) (Fig. 4a). AUROC was 0.85 ( P < 0.001) for predicting eIOH using IVCCI, the optimal threshold was 34.1% (sensitivity 91%, specificity 78%) (Fig. 4b); AUROC was 0.86 ( P < 0.001) for predicting eIOH using SVCDI, the optimal threshold was 17.8% (sensitivity 95%, specificity 71%) (Fig. 4c). Table 2 shows that the IVCCI (OR=1.20, 95% CI 1.09-1.31, P < 0.001) was associated with the occurrence of PIH in patients with AF, as did the IVCmax (OR=0.55, 95% CI 0.37-0.82, P < 0.001). Other parameters were not associated with the occurrence of PIH. Table 2 Multivariate logistic regression for prediction post-induction hypotension OR 95%CI P Age(years) 0.88 0.75~1.02 0.08 BMI 0.99 0.78~1.26 0.95 HR（per/min） 1.01 0.95~1.08 0.73 MAP（mmHg） 1.03 0.94~1.13 0.69 IVCmax（mm） 0.55 0.37~0.82 ＜0.05 IVCCI（%） 1.20 1.09~1.31 ＜0.001 BMI, body mass index; HR, heart rate; MAP, mean artery pressure; IVCmax, maximum inferior vena cava diameter; IVCCI, collapsibility index of inferior vena cava; OR, odds ratio;95%CI, 95% confidence interval. . Table 3 shows the results of multivariate linear regression analysis factors predicting eIOH in patients with AF. After adjusting for age, BMI, and baseHR, baseMAP, it was found that IVCCI (OR=1.16, 1.06-1.25, P <0.05) and SVCDI (OR=1.14, 1.02-1.27, P <0.05) were independent predictors of eIOH. Table 3 Unadjusted and adjusted odds ratios for predicting early intraoperative hypotension. Unadjusted analysis Adjusted analysis OR 95%CI P OR 95%CI P OR 95%CI P Age(years) 0.95 0.80~1.13 0.56 0.94 0.81~1.10 0.48 0.98 0.87~1.11 0.74 BMI 0.78 0.55~1.10 0.16 0.76 0.54~1.05 0.10 0.78 0.60~1.02 0.07 HR（per/min） 1.00 0.95~1.05 0.95 0.99 0.95~1.03 0.61 1.02 0.98~1.06 0.44 MAP（mmHg） 0.98 0.88~1.08 0.67 1.00 0.92~1.08 0.94 1.00 0.93~1.07 0.95 IVCmax（mm） 0.57 0.36~0.91 ＜0.05 0.53 0.34~0.81 ＜0.05 − − − IVC-CI（%） 1.14 1.03~1.26 ＜0.05 1.16 1.06~1.27 ＜0.05 − − − SVCmax（mm） 0.92 0.60~1.40 0.69 − − − 0.64 0.44~0.94 ＜0.05 SVC-DI（%） 1.12 1.00~1.25 0.06 − − − 1.14 1.02~1.27 ＜0.05 BMI, body mass index; HR, heart rate; MAP, mean artery pressure; IVCmax, maximum inferior vena cava diameter; IVCCI, collapsibility index of inferior vena cava; SVCmax, maximum superior vena cava diameter; SVCDI, distensibility index of superior vena cava; OR, odds ratio; 95%CI, 95% confidence interval. Discussion This observational study found that pre-operative ultrasound measurements of IVCCI was an independent predictor of PIH and eIOH ( P <0.001), while SVCDI was an independent predictor of eIOH ( P <0.001). Moreover, patients with AF who developed PIH and eIOH exhibited a higher preoperative IVCCI and SVCDI. In this study, 46% of AF patients experienced PIH, 30% experienced eIOH. All included patients were aged 65 years or older, suffered from AF, and over half had hypertension. Most were classified as ASA grade II or higher. During anesthesia induction, intravenous administration of drugs such as propofol and sufentanil can induce hypotension [20-21] . To minimize the impact of these drugs, induction dosages were calculated based on body weight. The pathophysiological characteristics of AF involve disrupted atrial electrical activity leading to fibrillatory motion instead of effective contraction, resulting in incomplete blood ejection from the atria and stasis, especially in the left atrium [22] . Furthermore, decreased vascular reactivity, increased sensitivity to anesthetics, and extended preoperative fasting and preparation times contribute to the inherent susceptibility of AF patients to cardiovascular instability and hypotension. During atrial fibrillation, heart rate and blood pressure exhibit low sensitivity in assessing volume responsiveness, and the unstable ventricular rate also renders many monitoring techniques that are feasible in normal patients unreliable as reference indicators. Perrine Bortolotti et al. reported that both IVCmax and IVCCI can predict fluid responsiveness in patients with arrhythmias in the ICU, with an area under the ROC curve of 0.93 (0.86-1) for both parameters. IVCmax < 11 mm predicted fluid responsiveness with a sensitivity of 83% and a specificity of 88%; an IVC-CI ≥ 39% predicted it with a sensitivity of 93% and a specificity of 88% [23] . Our study found that IVCmax predicts PIH in AF patients with an area under the ROC curve of 0.77 (0.65-0.88), a threshold of 19.4 mm, a sensitivity of 79%, and a specificity of 72%; IVCCI predicts PIH with an area under the ROC curve of 0.86 (0.75-0.97), a threshold of 34.1%, a sensitivity of 92%, and a specificity of 84%. Even in the presence of arrhythmias, IVCCI remains a predictive indicator of PIH. During general anesthesia with mechanical ventilation, transesophageal ultrasound assessment of the superior vena cava is relatively straightforward [ 24 ] . Compared to conventional ultrasound, transesophageal echocardiography (TEE) performs vascular measurements directly behind the heart through the esophagus. This approach avoids interference from chest structures and pulmonary gas, thereby obtaining clearer images and more challenging views to acquire than standard echocardiograms. Additionally, TEE employs higher-frequency probes, which provide superior resolution in vascular measurements and yield more accurate results [ 25 ] . The study found that during mechanical ventilation, the area under the ROC curve for SVCDI in predicting eIOH in AF patients was 0.86 (0.76–0.95). The cutoff was 17.8%, with a sensitivity of 95% and specificity of 71%, indicating a significant predictive relationship between SVCDI and eIOH. Patients who developed eIOH had higher SVCDI compared to those with early intraoperative normotension among atrial fibrillation patients. In a large cohort study, Vignon P et al. compared several dynamic echocardiographic parameters for predicting fluid responsiveness and reported that the area under the ROC curve of SVC-DI (0.75) was significantly greater than that of IVCmax (0.63) and PPV (0.67) in mechanically ventilated patients [ 26 ] . The optimal cutoff for SVC-DI was 21%, with a sensitivity of 61% and specificity of 84%. It has been demonstrated that venous collapsibility in the great veins results from systemic filling pressure-driven venous return, rather than aortic pressure transmission [27 – 29] . Charbonneau et al. found that in mechanically ventilated septic patients, the SVC demonstrated higher accuracy than the IVC in predicting fluid responsiveness. The threshold for SVC to predict fluid responsiveness was 29%, with a sensitivity of 54% and a specificity of 89%, while the threshold for IVC was 21%, with a sensitivity of 38% and a specificity of 61% [ 30 ] . These results are largely consistent with some of our findings.Consequently, assessing the vena cava collapsibility/distensibility index is clinically valuable for predicting hypotension. Even in the presence of AF, IVC-CI and SVC-DI can still serve as predictive indicators for hypotension during general anesthesia. There are some limitations of our study. A relatively small number of patients were included, although the estimated power of the study was sufficient to detect significant reliable results. The study participants were elderly patients with relatively unstable hemodynamics. These patients were administered various types of oral medications preoperatively, primarily including ventricular rate-controlling medications and antihypertensive medications, which may have affected the validity of the analysis at the extremes of collapsibility index. The relationship between preoperative oral administration of different medications and the magnitude of blood pressure reduction following induction and during the early intraoperative period requires more diverse clinical settings to validate and further develop the findings of this study. Conclusion In AF patients, IVCCI and SVCDI can predict the occurrence of PIH and eIOH, preoperative IVCCI>34.1% indicates a non-invasive predictor of PIH; SVCDI>17.8% suggest reliable predictors of eIOH. Abbreviations PIH: Post-induction hypotension; eIOH: Early intraoperative hypotension; IVCmax: Maximum inferior vena cava diameter; IVCmin: minimum inferior vena cava diameter; SVCmax: Maximum superior vena cava diameter; SVCmin: Minimum superior vena cava diameter; IVC-CI: Collapsibility index of inferior vena cava; SVC-DI: Distensibility index of superior vena cava; ROC: Receiver Operating Characteristics; MAP: Mean artery pressure. Declarations Acknowledgments Not applicable. Authors’ contributions XML: design the project; GSY, SWH, CHZ, collected the data; GSY, JZ analyzed and interpreted the data; XML wrote the manuscript; HJL and JZ critical revised the manuscript; All authors read and approved the final manuscript. Funding The study and publication of the manuscript was supported by the Shanghai Medical Innovation & Development Foundation (SMIDF2024-128-4). Medical Application Foundation of Suzhou (SKY2021042). Pudong New District Health Commission Key Discipline Cluster for Cardiovascular Diseases Development Program (PWZxq2022-11). Availability of data and materials The datasets generated and analyzed during the current study are available from the corresponding author in response to reasonable requests. Ethics approval and consent to participate This study was approved by the Institutional Ethics Committee of Shanghai Zhoupu Hospital (Ethical number: 2022-C-027-E0) and registered in Chinese Clinical Trial Register (registration number: ChiCTR2300072846). The study was also conformed to the ethical standards for medical research involving human subjects, as laid out in the 1964 Declaration of Helsinki and its later amendments.Written informed consent was obtained from each participant. Consent for publication Not applicable. Competing interests The authors declare that they have no competing interests. Publisher’sNote Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. References Shi S, Tang Y, Zhao Q, et al. Prevalence and risk of atrial fibrillation in China: a national cross-sectional epidemiological study. Lancet Regional Health-Western Pacific 2022; 100439. Masoudi FA, Calkins H, Kavinsky CJ, et al. 2015 ACC/HRS/SCAI left atrial appendage occlusion device societal overview. J Am Coll Cardiol 2015; 66:1497-513. van Waes JA, van Klei W A, Wijeysundera DN, et al. Association between intraoperative hypotension and myocardial injury after vascular surgery. Anesthesiology 2016; 124:35–44. Bijker JB, van Klei W A, Vergouwe Y, et al. Intraoperative hypotension and 1-year mortality after noncardiac surgery. Anesthesiology 2009; 111:1217–26. Walsh M, Devereaux PJ, Garg AX, et al. Relationship between intraoperative mean arterial pressure and clinical outcomes after noncardiac surgery: toward an empirical definition of hypotension. Anesthesiology 2013; 119:507–15. Lienhart A, Auroy Y, Pequignot F, et al. Survey of anesthesia-related mortality in France. Anesthesiology 2006; 105:1087–97. Reich DL, Hossain S, Krol M, et al. Predictors of hypotension after induction of general anesthesia. Anesth Analg 2005; 101:622–6. Südfeld S, Brechnitz S, Wagner JY, et al. Post-induction hypotension and early intraoperative hypotension associated with general anaesthesia. Br J Anaesth 2017; 119:57–64. Kalantari K, Chang JN, Ronco C, et al. Assessment of intravascular volume status and volume responsiveness in critically ill patients. Kidney int 2013; 83:1017–28. Peacock WF, soto KM. Current techniques of fluid status assessment. Contrib Nephrol 2010; 164:128–42. Çelebi Yamanoğlu NG, Yamanoğlu A, Parlak İ, et al. The role of inferior vena cava diameter in volume status monitoring; the best sonographic measurement method. Am J Emerg Med 2015; 33(3): 433-8. Zhang J, Critchley LA. Inferior Vena Cava Ultrasnography before General Anesthesia Can Predict Hypotension after Induction. Anesthesiology 2016; 124(3): 580-9. Eysenck W, Ammar A, Kanthasamy V, et al. A trial of three non-invasive blood pressure monitors compared with invasive blood pressure assessment in atrial fibrillation and sinus rhythm. Int J Clin Pract 2019; 13410. Zhang J, Critchley LA. Inferior vena cava ultrasonography before general anesthesia can predict hypotension after induction. Anesthesiology 2016; 124:580-9. Mitchell C, Rahko PS, Blauwet LA, et al. Guidelines for Performing a Comprehensive Transthoracic Echocardiographic Examination in Adults: Recommendations from the American Society of Echocardiography. American Society Echocardiogrphy 2019; 32:1-64. Mantovani MM, Fantoni DT, Gimenes AM, et al. Clinical monitoring of cardiac output assessed by transoesophageal echocardiography in anesthetised dogs: a comparison with the thermodilution technique. Biomedical Chromatogaphy 2017; 13(1):325. Futier E, Lefrant JY, Guinot PG, et al. Effect of individualized vs standard blood pressure management strategies on postoperative organ dysfunction among high-risk patients undergoing major surgery: A Randomized Clinical Trial. JAMA. 2017, 318(14): 1346-57. Turan A, Chang C, Cohen B, et al. Incidence, severity, and detection of blood pressure perturbations after abdominal surgery: A prospective blinded observational study. Anesthesiology 2019; 130(4):550-9. DeLong eR, DeLong DM, Clarke-Pearson DL. Comparing the areas under two or more correlated receiver operating characteristic curves: A nonparametric approach. Biometrics 1988; 44:837–45. Möller Petrun A, Kamenik M. Bispectral index-guided induction of general anesthesia in patients undergoing major abdominal surgery using propofol or etomidate: a double-blind, randomized, clinical trial. British Journal of Anesthesia 2013; 110(3): 388-96. Green RS, Butler MB. Post-intubation hypotension in general anesthesia: A retrospective analysis. Journal Intensive Care Medicine 2016; 31(10): 667-75. Eichenlaub M, Mueller-Edenborn B, Minners J, et al. Left atrial hypertension, electrical conduction slowing, and mechanical dysfunction: The pathophysiological triad in atrial fibrillation-associated atrial cardiomyopathy. Front Physiol 2021; 12: 670527. Bortolotti P, Colling D, Colas V, et al. Respiratory changes of the inferior vena cava diameter predict fluid responsiveness in spontaneously breathing patients with cardiac arrhythmias. Annals of Intensive Care 2018; 8(1): 79. Cowie BS, Kluger R, Rex S, et al. The relationship between superior vena cava diameter and collapsibility and central venous pressure. Anesthesia Intensive Care 2015; 43(3): 357-60. Cioccari L, Baur HR, Berger D, et al. Hemodynamic assessment of critically ill patients using a miniaturized transesophageal echocardiography probe. Critical Care 2013; 17(3):121. Vignon P, Repessé X, Bégot E, et al. Comparison of echocardiographic indices used to predict fluid responsiveness in ventilated patients. American Journal of Respiratory Critical Care Medicine 2017; 195:1022-32. Nakamura K, Tomida M, Ando T, et al. Cardiac variation of inferior vena cava: new concept in the evaluation of intravascular blood volume. Journal Medical Ultrasonics 2013; 40:205-9. Nakamura K, Qian K, Ando T, et al. Cardiac variation of internal jugular vein for the evaluation of hemodynamics. Ultrasound In Medicine and Biology 2016; 42: 1764-70. Deng Y, Dong J, Zhou J, et al. Dynamic assessment of the central vein throughout the cardiac cycle in adults with no right heart disease by cardiac CT. Clinical Imaging 2021; 69:120-5. Charbonneau H, Riu B, Faron M, et al. Predicting preload responsiveness using simultaneous recordings of inferior and superior vena cava diameters. Critical Care 2014; 18(5):473. Additional Declarations No competing interests reported. Supplementary Files BMCSTROBEchecklistv4combinedPlosMedicine.docx Cite Share Download PDF Status: Published Journal Publication published 01 Sep, 2025 Read the published version in BMC Anesthesiology → Version 1 posted Editorial decision: Revision requested 07 Jul, 2025 Reviews received at journal 05 Jul, 2025 Reviewers agreed at journal 03 Jul, 2025 Reviewers agreed at journal 02 Jul, 2025 Reviewers agreed at journal 02 Jul, 2025 Reviewers agreed at journal 12 Jun, 2025 Reviews received at journal 26 May, 2025 Reviewers agreed at journal 20 May, 2025 Reviewers agreed at journal 30 Apr, 2025 Reviewers invited by journal 29 Apr, 2025 Editor assigned by journal 29 Apr, 2025 Editor invited by journal 28 Apr, 2025 Submission checks completed at journal 27 Apr, 2025 First submitted to journal 27 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6444922","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":449534790,"identity":"d5f2538e-eeeb-496d-b77f-352ea43950dc","order_by":0,"name":"Xiaomei Li","email":"","orcid":"","institution":"Department of Anesthesiology, The Second Affiliated Hospital of Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Xiaomei","middleName":"","lastName":"Li","suffix":""},{"id":449534791,"identity":"8f6c5f9e-7b8d-486e-ba1e-847fea475fa5","order_by":1,"name":"Guangsui Yang","email":"","orcid":"","institution":"Department of Anesthesiology, The Shanghai Zhoupu Hospital","correspondingAuthor":false,"prefix":"","firstName":"Guangsui","middleName":"","lastName":"Yang","suffix":""},{"id":449534792,"identity":"43c89b35-c10e-4e33-bd9d-3f4807f4cc61","order_by":2,"name":"Suwen Hao","email":"","orcid":"","institution":"Department of Anesthesiology, The Shanghai Zhoupu Hospital","correspondingAuthor":false,"prefix":"","firstName":"Suwen","middleName":"","lastName":"Hao","suffix":""},{"id":449534793,"identity":"cf5f2e81-fedc-4051-925e-6fde2101f736","order_by":3,"name":"Changhua Zhu","email":"","orcid":"","institution":"Department of Anesthesiology, The Second Affiliated Hospital of Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Changhua","middleName":"","lastName":"Zhu","suffix":""},{"id":449534794,"identity":"75276c05-762a-4427-8ad0-f45944997e16","order_by":4,"name":"Haijian Liu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+UlEQVRIiWNgGAWjYBACPmYGNgYGAzYeBgbGxsd/Kmx4+Pkb8GthQ2hhbjbgOZMmIznjAAEtYAQG7G0SvG2HbQwaEghoYecxe/CjgE+Gf3Zjm4TEmfM8BgwHGD98zMHnMB5zwx6gwyTuHGy2MKi4zWPO3MAsOXMbXi1mEjwgv9xIbLyRcOY2j2XDATZmXgJaJP8AtcjfSGyQONh2jsfgQAJhLdIgWwxuJDZJNrYdIEYLW5m0DFCL4Y3EZmOGM8k8kjMONuP1Cz//4W2Sb/4cs5e7kf7wMUOFnT0/f/PBDx/xaIGCY8gcxgaC6oGghhhFo2AUjIJRMFIBANlGSGrTkWqvAAAAAElFTkSuQmCC","orcid":"","institution":"Department of Anesthesiology, The Shanghai Zhoupu Hospital","correspondingAuthor":true,"prefix":"","firstName":"Haijian","middleName":"","lastName":"Liu","suffix":""},{"id":449534795,"identity":"6e7bf2fb-aabb-444d-b64a-12a33a4032f7","order_by":5,"name":"Jiang Zhu","email":"","orcid":"","institution":"Department of Anesthesiology, The Second Affiliated Hospital of Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Jiang","middleName":"","lastName":"Zhu","suffix":""}],"badges":[],"createdAt":"2025-04-14 10:08:30","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6444922/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6444922/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12871-025-03295-5","type":"published","date":"2025-09-01T15:57:01+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":82162906,"identity":"4ab91412-b93c-468d-a28f-d635de2ef7b5","added_by":"auto","created_at":"2025-05-07 08:51:56","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":336026,"visible":true,"origin":"","legend":"\u003cp\u003eM-mode assessment of IVCmax and IVCmin were measured during spontaneous breathing (a); TEE assessment of SVCmax and SVCmin were measured during mechanical ventilation (b).\u003c/p\u003e","description":"","filename":"Fig.1.ppt1.png","url":"https://assets-eu.researchsquare.com/files/rs-6444922/v1/a6dc682ba7f2bb61f649e267.png"},{"id":82162370,"identity":"a2824531-e809-47c8-8152-f3096777327a","added_by":"auto","created_at":"2025-05-07 08:43:56","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":185301,"visible":true,"origin":"","legend":"\u003cp\u003eSTROBE flow diagram.\u003c/p\u003e\n\u003cp\u003eAF, atrial fibrillation; MAP, mean artery pressure; IVC, inferior vena cava; SVC, superior vena cava; PIH, post-induction hypotension; eIOH, early intraoperative hypotension.\u003c/p\u003e","description":"","filename":"Figure2WebDisplay.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6444922/v1/e4ae495658e00f274b70af27.jpg"},{"id":82162368,"identity":"ab8268bb-ee0f-48ce-87b0-2606cab29cbb","added_by":"auto","created_at":"2025-05-07 08:43:56","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":273774,"visible":true,"origin":"","legend":"\u003cp\u003eScatter plots of IVCmax and IVCCI vs. post-induction (a) and early intraoperative hypotension decrease (b), and SVCmax with SVCDI (c) vs. early intraoperative hypotension decrease.\u003c/p\u003e","description":"","filename":"Figure3WebDisplay.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6444922/v1/3fcf7b4f0e99e1ea48a83a4f.jpg"},{"id":82162905,"identity":"a99179e2-7b6a-49a7-b1fb-3bddc2b107b6","added_by":"auto","created_at":"2025-05-07 08:51:56","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":331478,"visible":true,"origin":"","legend":"\u003cp\u003eReceiver operating characteristics (ROC) curve of IVCmax and IVCCI for predicting post-induction (a) and early intraoperative (b) hypotension; SVCmax with SVCDI (c) for early intraoperative hypotension.\u003c/p\u003e","description":"","filename":"Figure4WebDisplay.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6444922/v1/fe89867cf2e8634f80564be5.jpg"},{"id":90827885,"identity":"a442d5fd-0208-409f-bb40-fccbf90f4f7f","added_by":"auto","created_at":"2025-09-08 16:02:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1955489,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6444922/v1/353264bb-e754-442b-ae79-c91297b86a92.pdf"},{"id":82162366,"identity":"cb4d1e86-95ee-48f8-b433-8b28662703c4","added_by":"auto","created_at":"2025-05-07 08:43:56","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":98690,"visible":true,"origin":"","legend":"","description":"","filename":"BMCSTROBEchecklistv4combinedPlosMedicine.docx","url":"https://assets-eu.researchsquare.com/files/rs-6444922/v1/437940de592802c6a139053d.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Ultrasonography evaluation of the inferior vena cava collapsibility index and the superior vena cava distensibility index for predicting hypotension during general anesthesia in atrial fibrillation patients：a prospective observational study","fulltext":[{"header":"Background","content":"\u003cp\u003eAtrial fibrillation (AF) is one of the most common arrhythmias in adults, with a reported incidence and prevalence of 1.6% in China\u003csup\u003e[1]\u003c/sup\u003e. AF elevates the risk of ischemic stroke and systemic arterial embolism. In recent years, various open and percutaneous left atrial appendage occlusion devices have been developed, and some have shown comparable effectiveness to anticoagulants in preventing strokes in patients with AF\u003csup\u003e[2]\u003c/sup\u003e. Percutaneous left atrial appendage closure, commonly performed under general anesthesia to optimize procedural conditions through patient immobilization and prolonged transesophageal echocardiography (TEE), poses a significant risk of hypotension. This complication is particularly pronounced in elderly patients with pre-existing cardiovascular comorbidities. A decrease in arterial pressure during anesthesia induction can result in perioperative complications, such as acute kidney injury, heart failure, cerebral ischemia, and myocardial infarction\u003csup\u003e[3-6]\u003c/sup\u003e. Factors predicting hypotension include age, a higher American Society of Anesthesiologists (ASA) physical status, use of propofol, dosage of fentanyl, and importantly, volume status\u003csup\u003e[7-8]\u003c/sup\u003e. Patients with AF also face an increased risk of post-induction hypotension (PIH) or\u0026nbsp;early intraoperative hypotension (eIOH) during general anesthesia. Recently recommended dynamic parameters for assessing volume status include ultrasound measurements of the inferior vena cava (IVC) diameter with respiration\u003csup\u003e[9-10]\u003c/sup\u003e. These parameters, such as the maximum diameter of the IVC (IVCmax) at the end of expiration and the collapsibility index (CI), have been suggested as rapid, noninvasive methods to predict anesthesia-related hypotension\u003csup\u003e[11-12]\u003c/sup\u003e. However, patients with AF lack atrial contraction support during left ventricular diastolic filling, which can lead to elevated left atrial pressure and necessitate greater volume management. Additionally, AF may compromise the utility of cardiopulmonary interaction-based volume status measurements, such as stroke volume variation\u003csup\u003e[13]\u003c/sup\u003e. The effectiveness of IVC variability as an indicator in patients with AF has yet to be explored.\u003c/p\u003e\n\u003cp\u003eThis study aims to explore the clinical value of the inferior vena cava collapsibility index and the superior vena cava distensibility index in predicting the occurrence of PIH and eIOH events in atrial fibrillation patients.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003ePatients\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe selected 77 patients with atrial fibrillation (aged 65\u0026ndash;85) who underwent left atrial appendage occlusion under general anesthesia at Shanghai Zhoupu Hospital between June 2022 and January 2023, based on sample size calculations. The study protocol was reviewed and approved by the Institutional Ethics Committee of Shanghai Zhoupu Hospital (Registration number:2022-C-027-E0) and conformed to the ethical standards for medical research involving human subjects, as laid out in the 1964 Declaration of Helsinki and its later amendments. Participants provided written informed consent prior to taking part in the study The trial was registered at http://www.chictr.org.cn (registration number:ChiCTR2300072846) on 27 June 2023. Our reporting adhered to the STROBE guidelines. Participants in this study were at least 65 years old, with a body mass index (BMI) ranging from 18 to 32 kg m\u003csup\u003e-\u003c/sup\u003e\u0026sup2;, an American Society of Anesthesiologists (ASA) physical status of 2 to 3, and scheduled for left atrial appendage occlusion. The exclusion criteria were as follows: emergency surgery, sudden life-threatening changes in vital signs, elevated intra-abdominal pressure, expected airway or mental dysfunction, diseases of the autonomic nervous system, current use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, presence of an implantable pacemaker or cardioverter, peripheral vascular disease, serious cardiovascular conditions, unstable angina, and an ejection fraction (EF) of less than 40%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUpon entering the room, peripheral veins were opened, and lactated Ringer\u0026apos;s solution was administered at a rate of 30 drops per minute, along with a pre-treatment of 0.05 mg kg\u003csup\u003e-1\u003c/sup\u003e of midazolam. Patients were conscious, lying supine, and breathing spontaneously for at least five minutes before the examination. The maximum (IVCmax) and minimum (IVCmin) diameters of the inferior vena cava were measured using ultrasound during one spontaneous respiratory cycle in AF patients, as shown in Fig 1a. The collapsibility index of inferior vena cava (IVCCI) was calculated using the following equation: collapsibility index = (IVCmax-IVCmin)/IVCmax*100\u003csup\u003e[14]\u003c/sup\u003e.\u0026nbsp;The ultrasound measurement of the inferior vena cava was performed as follows: the patient was positioned supine without a pillow, with hands relaxed at the sides, following the method described by the American Society of Echocardiography\u003csup\u003e[15]\u003c/sup\u003e:\u0026nbsp;The subxiphoid approach was used, with a phased-array probe from a\u0026nbsp;Siemens Healthineers ACUSON SC2000 machine\u0026nbsp;placed subxiphoid to display the four-chamber view. The probe was then rotated downward towards the spine, with the orientation marker pointing towards the patient\u0026apos;s head, to show the inferior vena cava entering the right atrium and the hepatic veins joining the inferior vena cava. The diameter of the inferior vena cava was measured 2\u0026nbsp;cm from the right atrial entrance,\u0026nbsp;IVCmax\u0026nbsp;and\u0026nbsp;IVCmin\u0026nbsp;were measured by freezing the ultrasound image at end-expiration and end-inspiration respectively. Each site was measured three times, and the average was taken; measurements differing by more than 2 mm were excluded.\u003c/p\u003e\n\u003cp\u003eAfter anesthesia induction, the maximum (SVCmax) and minimum (SVCmin) diameters of the superior vena cava were measured using a transesophageal ultrasound probe from a Siemens machine over one mechanical ventilation respiratory cycle in AF patients, as shown in Fig 1b. The distensibility index of superior vena cava (SVCDI) was calculated using the following equation: distensibility index = (SVCmax-SVCmin)/SVCmin*100\u003csup\u003e[16]\u003c/sup\u003e. The transesophageal ultrasound measurement of the superior vena cava was performed as follows: after the patient was under general anesthesia and mechanically ventilated, the transesophageal ultrasound was adjusted to a depth of 10 cm based on the mid-esophageal bicaval view. This view clearly displayed the left atrium, right atrium, interatrial septum, superior vena cava, inferior vena cava, partial pulmonary veins, and their connections to the right atrium, from which SVCmax and SVCmin were obtained. Each site was measured three times, and the average was taken; measurements differing by more than 2 mm were excluded. The measurement process did not exceed 3 minutes, and the entire induction period did not exceed 5 minutes. All ultrasound measurements were performed by an experienced anesthesiologist who was blinded to the study.\u003c/p\u003e\n\u003cp\u003eArterial pressure was measured invasively using an arterial line catheter, which was inserted before anesthesia induction. Hemodynamic data were collected both before (baseline) and after induction. Post-induction hypotension (PIH) was defined by a decrease in mean arterial pressure (MAP) of more than 20% from baseline or any recorded period of MAP below 60 mmHg\u003csup\u003e[17]\u003c/sup\u003e. MAP is continuously monitored and recorded within the first 15 minutes after the start of surgery. Early intraoperative hypotension (eIOH) was defined as a MAP below 60 mmHg or a reduction of more than 20% from the baseline level within the first 15 minutes after skin incision\u003csup\u003e[8]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eAnesthesia induction involved a regimen of sufentanil (0.35 \u0026micro;g kg\u003csup\u003e-1\u003c/sup\u003e) and propofol (1.5 mg kg\u003csup\u003e-1\u003c/sup\u003e), followed by tracheal intubation facilitated by cisatracurium (1.5 mg kg\u003csup\u003e-1\u003c/sup\u003e). Anesthesia was maintained with 1.5 vol% inhaled sevoflurane in oxygen-enriched air and remifentanil continuously infused at 6 \u0026micro;g kg\u003csup\u003e-1\u0026nbsp;\u003c/sup\u003eh\u003csup\u003e-1\u003c/sup\u003e. In cases of severe hypotension (MAP \u0026lt; 55 mmHg) or prolonged hypotension episodes (lasting\u0026nbsp;\u0026ge;\u0026nbsp;3 minutes) during the induction phase or early intraoperative period, intravenous ephedrine 6 mg or norepinephrine infusion at 200 \u0026micro;g h\u003csup\u003e-1[18]\u003c/sup\u003e. However, patients who experience severe hypotension requiring pharmacological intervention during the induction phase or early intraoperative period are excluded.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSample size\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe sample size was calculated using PASS15.0 software, commonly utilized in clinical research. Based on a literature review, we used the following parameters: the sensitivity of the IVC to predict intraoperative hypotension is 80%, the specificity is 90%, \u0026alpha;=0.05. The calculation indicated that 70 cases are needed for this study. To account for a potential dropout rate of 10%, 77 AF patients will be included.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eData analysis\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData were compiled and analyzed using Microsoft Excel, for statistical analyses, we employed StataMP16 and PRISM. Continuous variables are presented as means \u0026plusmn; standard deviations if they are normally distributed, as confirmed by the Shapiro-Wilk W test. Non-normally distributed data are displayed as medians and interquartile ranges. For comparisons, we used Student\u0026apos;s two-sample t-test and the Mann-Whitney U test. Categorical variables are shown as percentages and absolute case numbers. The \u0026chi;\u003csup\u003e2\u003c/sup\u003e-test and Fisher\u0026apos;s exact test were used for analyzing contingency tables as appropriate. Two-sided p-values are reported, with a significance threshold set at p \u0026lt;0.05. The pearson correlation coefficient (\u003cem\u003er\u003c/em\u003e) was utilized to evaluate the association between measurements and the percentage decrease in MAP from baseline after the induction of general anesthesia.\u003c/p\u003e\n\u003cp\u003eROC curve analysis was conducted to evaluate the predictive capability of the two ultrasound-derived parameters, IVCCI and SVCDI, for clinically significant of PIH and eIOH. The areas under the curves (AUCs) with 95% confidence intervals were computed. We compared the two ROC curves using the nonparametric method described by DeLong et al\u003csup\u003e[19]\u003c/sup\u003e. Optimal cutoff values were determined by the values that maximize the Youden index (sensitivity+specificity-1). Logistic regression was employed to validate the risk factors for PIH and eIOH in AF patients.\u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 77 AF patients were initially included in this analysis, however, 7 were subsequently excluded due to inadequately visualized IVC in 3 cases and missing data in 4 cases, as shown in Fig 2. Ultimately, 70 AF patients were analyzed. Thirty-four\u0026nbsp;\u003c/p\u003e\n\u003cp\u003epatients were male and 36 were female. Their mean age was 75.2 \u0026plusmn; 6.3 years, mean BMI was 23.9 \u0026plusmn; 3.2 kg m\u003csup\u003e-2\u003c/sup\u003e. Fifteen patients were ASA 2, while 55 were ASA 3.\u0026nbsp;Thirty-two\u0026nbsp;patients developed PIH after induction, 21 patients developed eIOH after skin incision. When comparing AF patients who developed PIH and eIOH with those who did not, we found that there were no significant differences between the two groups as regards sex, BMI, ASA status, baseline MAP or HR.\u0026nbsp;Significant differences\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ewere observed in the IVCmax and IVCCI, where AF patients with PIH had a significantly higher IVCCI (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) and a lower IVCmax (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.005) compared to those who did not.\u0026nbsp;Similarly, patients with\u0026nbsp;AF\u0026nbsp;who developed eIOH, both IVCmax and SVCmax were significantly lower than in the normal blood pressure group, whereas IVCCI and SVCDI were significantly higher\u0026nbsp;(\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001).The demographic characteristics of AF patients are summarized in Table 1.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAfter anesthesia induction, the IVCmax showed a low-degree negative correlation with the percentage decrease in MAP (\u003cem\u003er\u003c/em\u003e＝\u0026minus;0.42, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001). On the other hand, the IVCCI exhibited a significant positive correlation with the decrease in MAP\u003c/p\u003e\n\u003cp\u003e(\u003cem\u003er\u003c/em\u003e＝0.55, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) (Fig.3a). During the early intraoperative period, IVCmax showed a low-degree negative correlation with the percentage decrease in MAP (\u003cem\u003er\u003c/em\u003e＝\u0026minus;0.48, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001), while IVCCI exhibited a low-degree positive correlation (\u003cem\u003er\u003c/em\u003e＝0.45, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) (Fig. 3b). SVCmax demonstrated a significant negative correlation with the percentage decrease in MAP (\u003cem\u003er\u003c/em\u003e＝\u0026minus;0.54, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001), and SVCDI showed a significant positive correlation with the decrease in MAP (\u003cem\u003er\u003c/em\u003e＝\u0026minus;0.54, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) (Fig. 3c).\u003c/p\u003e\n\u003cp\u003eTable 1 Comparison of characteristics of AF patients with post-induction hypotension and early intraoperative hypotension\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDeveloped PIH\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 163px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDeveloped eIOH\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cstrong\u003evariables\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eYes(\u003cem\u003en\u003c/em\u003e=32)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNo(\u003cem\u003en\u003c/em\u003e=38)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eYes(\u003cem\u003en\u003c/em\u003e=21)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eYes(\u003cem\u003en\u003c/em\u003e=21)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eAge(years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e74.7 \u0026plusmn; 5.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e75.6 \u0026plusmn; 7.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e75.7 \u0026plusmn; 5.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e75.0 \u0026plusmn; 6.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e0.68\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eSex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e17（24%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e17（24%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e12（17%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e22（31%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e15（22%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e21（30%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e9（13%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e27（39%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eBMI（%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e18~23.99 Kg m\u003csup\u003e-2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e19（27%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e17（24%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e15（21%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e21（30%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e24~27.99 Kg m\u003csup\u003e-2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e8（12%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e16（23%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e5（8%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e19（27%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e28~32 Kg m\u003csup\u003e-2\u003c/sup\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e5（7%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e5（7%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e1（1%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e9（13%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eASA physical status\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e7（10%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e8（11%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e6（9%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e9（13%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eIII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e25（36%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e30（43%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e15（21%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e15（21%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eMAP（mmHg）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e107.1 \u0026plusmn; 13.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e103.0 \u0026plusmn; 11.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e110.3 \u0026plusmn; 15.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e103.6 \u0026plusmn; 11.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eHR（per/min）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e80.0 \u0026plusmn; 21.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e74.1 \u0026plusmn; 11.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e77.5 \u0026plusmn; 14.4\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e76.5 \u0026plusmn; 17.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e0.83\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eIVCmax(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e18.4 \u0026plusmn; 3.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e21.2 \u0026plusmn; 2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e＜0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e17.5 \u0026plusmn; 3.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e21.0 \u0026plusmn; 2.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e＜0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eIVCCI(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e40.9 \u0026plusmn; 12.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e23.8 \u0026plusmn; 8.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e＜0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e43.0\u0026plusmn; 10.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e26.8\u0026plusmn; 12.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e＜0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eSVCmax(mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e－\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e－\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e15.3 \u0026plusmn; 2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e18.6 \u0026plusmn; 2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e＜0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eSVCDI(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e－\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 86px;\"\u003e\n \u003cp\u003e－\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e26.6 \u0026plusmn; 7.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e16.0 \u0026plusmn; 7.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e＜0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eValues are mean \u0026plusmn; SD, number of patients or number (%). BMI, body mass index; ASA, American Society of Anesthesiologists; MAP, mean artery pressure; HR, heart rate; IVCmax, maximum inferior vena cava diameter; IVCCI, collapsibility index of inferior vena cava; SVCmax, maximum superior vena cava diameter; SVCDI, distensibility index of superior vena cava; PIH, post-induction hypotension; eIOH, early intraoperative hypotension.\u003c/p\u003e\n\u003cp\u003eThe ROC curve analysis showed that AF patients with a\u0026nbsp;AUROC\u0026nbsp;of\u0026nbsp;95% confidence intervals was\u0026nbsp;0.77\u0026nbsp;(\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) for IVCCI and 0.86 (P \u0026lt; 0.001) for IVCmax to predict PIH. The optimal threshold for IVCmax was 19.4 mm (sensitivity 72%, specificity 79%), while for IVCCI it was 34.1% (sensitivity 84%, specificity 92%) (Fig. 4a). AUROC was 0.85 (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) for predicting eIOH using IVCCI, the optimal threshold was 34.1% (sensitivity 91%, specificity 78%) (Fig. 4b); AUROC was 0.86 (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) for predicting eIOH using SVCDI, the optimal threshold was 17.8% (sensitivity 95%, specificity 71%) (Fig. 4c).\u003c/p\u003e\n\u003cp\u003eTable 2 shows that the IVCCI (OR=1.20, 95% CI 1.09-1.31,\u0026nbsp;\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) was associated with the occurrence of PIH in patients with AF,\u0026nbsp;as did the IVCmax\u0026nbsp;(OR=0.55, 95% CI 0.37-0.82,\u0026nbsp;\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001). Other parameters were not associated with the occurrence of PIH.\u003c/p\u003e\n\u003cp\u003eTable 2 Multivariate logistic regression for prediction post-induction hypotension\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"91%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 35px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e95%CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 35px;\"\u003e\n \u003cp\u003eAge(years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18px;\"\u003e\n \u003cp\u003e0.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e0.75~1.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21px;\"\u003e\n \u003cp\u003e0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 35px;\"\u003e\n \u003cp\u003eBMI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18px;\"\u003e\n \u003cp\u003e0.99\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e0.78~1.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21px;\"\u003e\n \u003cp\u003e0.95\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 35px;\"\u003e\n \u003cp\u003eHR（per/min）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18px;\"\u003e\n \u003cp\u003e1.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e0.95~1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21px;\"\u003e\n \u003cp\u003e0.73\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 35px;\"\u003e\n \u003cp\u003eMAP（mmHg）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18px;\"\u003e\n \u003cp\u003e1.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e0.94~1.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21px;\"\u003e\n \u003cp\u003e0.69\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 35px;\"\u003e\n \u003cp\u003eIVCmax（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18px;\"\u003e\n \u003cp\u003e0.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e0.37~0.82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21px;\"\u003e\n \u003cp\u003e＜0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 35px;\"\u003e\n \u003cp\u003eIVCCI（%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18px;\"\u003e\n \u003cp\u003e1.20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e1.09~1.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21px;\"\u003e\n \u003cp\u003e＜0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eBMI, body mass index; HR, heart rate; MAP, mean artery pressure; IVCmax, maximum inferior vena cava diameter; IVCCI, collapsibility index of inferior vena cava; OR, odds ratio;95%CI, 95% confidence interval. .\u003c/p\u003e\n\u003cp\u003eTable 3 shows the results of multivariate linear regression analysis factors predicting eIOH in patients with AF. After adjusting for age, BMI, and baseHR, baseMAP, it was found that IVCCI\u0026nbsp;(OR=1.16,\u0026nbsp;1.06-1.25,\u003cem\u003e\u0026nbsp;P\u003c/em\u003e\u0026lt;0.05)\u0026nbsp;and SVCDI\u0026nbsp;(OR=1.14,\u0026nbsp;1.02-1.27,\u003cem\u003e\u0026nbsp;P\u003c/em\u003e\u0026lt;0.05)\u0026nbsp;were\u0026nbsp;independent predictors\u0026nbsp;of\u0026nbsp;eIOH.\u003c/p\u003e\n\u003cp\u003eTable 3 Unadjusted and adjusted odds ratios for predicting early intraoperative hypotension.\u003c/p\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"563\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" style=\"width: 152px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eUnadjusted analysis\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"6\" style=\"width: 314px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAdjusted analysis\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e95%CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e95%CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e95%CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 39px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003eAge(years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e0.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.80~1.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37px;\"\u003e\n \u003cp\u003e0.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e0.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.81~1.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e0.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e0.98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e0.87~1.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 39px;\"\u003e\n \u003cp\u003e0.74\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003eBMI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e0.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.55~1.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37px;\"\u003e\n \u003cp\u003e0.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e0.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.54~1.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e0.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e0.60~1.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 39px;\"\u003e\n \u003cp\u003e0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003eHR（per/min）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.95~1.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37px;\"\u003e\n \u003cp\u003e0.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e0.99\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.95~1.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e0.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e1.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e0.98~1.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 39px;\"\u003e\n \u003cp\u003e0.44\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" style=\"width: 138px;\"\u003e\n \u003cp\u003eMAP（mmHg）\u0026nbsp; \u0026nbsp; \u0026nbsp;0.98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.88~1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37px;\"\u003e\n \u003cp\u003e0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.92~1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e0.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e0.93~1.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 39px;\"\u003e\n \u003cp\u003e0.95\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" style=\"width: 138px;\"\u003e\n \u003cp\u003eIVCmax（mm）\u0026nbsp; \u0026nbsp; \u0026nbsp;0.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 111px;\"\u003e\n \u003cp\u003e0.36~0.91 \u0026nbsp; \u0026nbsp;＜0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e0.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 120px;\"\u003e\n \u003cp\u003e0.34~0.81 \u0026nbsp; \u0026nbsp; \u0026nbsp;＜0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 39px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003eIVC-CI（%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e1.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 111px;\"\u003e\n \u003cp\u003e1.03~1.26 \u0026nbsp; \u0026nbsp;＜0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e1.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 120px;\"\u003e\n \u003cp\u003e1.06~1.27 \u0026nbsp; \u0026nbsp; \u0026nbsp;＜0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 39px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" style=\"width: 138px;\"\u003e\n \u003cp\u003eSVCmax（mm）\u0026nbsp; \u0026nbsp; 0.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.60~1.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37px;\"\u003e\n \u003cp\u003e0.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e0.64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 109px;\"\u003e\n \u003cp\u003e0.44~0.94 \u0026nbsp; \u0026nbsp;＜0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 97px;\"\u003e\n \u003cp\u003eSVC-DI（%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e1.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e1.00~1.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 37px;\"\u003e\n \u003cp\u003e0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026minus;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003e1.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 109px;\"\u003e\n \u003cp\u003e1.02~1.27 \u0026nbsp; \u0026nbsp;＜0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eBMI, body mass index; HR, heart rate; MAP, mean artery pressure; IVCmax, maximum inferior vena cava diameter; IVCCI, collapsibility index of inferior vena cava; SVCmax, maximum superior vena cava diameter; SVCDI, distensibility index of superior vena cava; OR, odds ratio; 95%CI, 95% confidence interval.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis observational study found that pre-operative ultrasound measurements of\u0026nbsp;IVCCI was an independent predictor of\u0026nbsp;PIH\u0026nbsp;and eIOH\u0026nbsp;(\u003cem\u003eP\u003c/em\u003e\u0026lt;0.001),\u0026nbsp;while\u0026nbsp;SVCDI was an\u0026nbsp;independent predictor of\u0026nbsp;eIOH\u0026nbsp;(\u003cem\u003eP\u003c/em\u003e\u0026lt;0.001). Moreover, patients with AF who developed PIH and eIOH exhibited a higher preoperative IVCCI and SVCDI.\u003c/p\u003e\n\u003cp\u003eIn this study, 46% of AF patients experienced PIH, 30% experienced eIOH. All included patients were aged 65 years or older, suffered from AF, and over half had hypertension. Most were classified as ASA grade II or higher. During anesthesia induction, intravenous administration of drugs such as propofol and sufentanil can induce hypotension\u003csup\u003e[20-21]\u003c/sup\u003e. To minimize the impact of these drugs, induction dosages were calculated based on body weight. The pathophysiological characteristics of AF involve disrupted atrial electrical activity leading to fibrillatory motion instead of effective contraction, resulting in incomplete blood ejection from the atria and stasis, especially in the left atrium\u003csup\u003e[22]\u003c/sup\u003e. Furthermore, decreased vascular reactivity, increased sensitivity to anesthetics, and extended preoperative fasting and preparation times contribute to the inherent susceptibility of AF patients to cardiovascular instability and hypotension.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDuring atrial fibrillation, heart rate and blood pressure exhibit low sensitivity in assessing volume responsiveness, and the unstable ventricular rate also renders many monitoring techniques that are feasible in normal patients unreliable as reference indicators.\u0026nbsp;Perrine Bortolotti et al. reported that both IVCmax and IVCCI can predict fluid responsiveness in patients with arrhythmias in the ICU, with an area under the ROC curve of 0.93 (0.86-1) for both parameters. IVCmax \u0026lt; 11 mm predicted fluid responsiveness with a sensitivity of 83% and a specificity of 88%; an IVC-CI \u0026ge; 39% predicted it with a sensitivity of 93% and a specificity of 88%\u003csup\u003e[23]\u003c/sup\u003e. Our study found that IVCmax predicts PIH in AF patients with an area under the ROC curve of 0.77 (0.65-0.88), a threshold of 19.4 mm, a sensitivity of 79%, and a specificity of 72%; IVCCI predicts PIH with an area under the ROC curve of 0.86 (0.75-0.97), a threshold of 34.1%, a sensitivity of 92%, and a specificity of 84%. Even in the presence of arrhythmias, IVCCI remains a predictive indicator of PIH.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDuring general anesthesia with mechanical ventilation, transesophageal ultrasound assessment of the superior vena cava is relatively straightforward\u003csup\u003e[\u003c/sup\u003e\u003csup\u003e24\u003c/sup\u003e\u003csup\u003e]\u003c/sup\u003e. Compared to conventional ultrasound, transesophageal echocardiography (TEE) performs vascular measurements directly behind the heart through the esophagus. This approach avoids interference from chest structures and pulmonary gas, thereby obtaining clearer images and more challenging views to acquire than standard echocardiograms. Additionally, TEE employs higher-frequency probes, which provide superior resolution in vascular measurements and yield more accurate results\u003csup\u003e[\u003c/sup\u003e\u003csup\u003e25\u003c/sup\u003e\u003csup\u003e]\u003c/sup\u003e. The study found that during mechanical ventilation, the area under the ROC curve for SVCDI in predicting eIOH in AF patients was 0.86 (0.76\u0026ndash;0.95). The cutoff was 17.8%, with a sensitivity of 95% and specificity of 71%, indicating a significant predictive relationship between SVCDI and eIOH. Patients who developed eIOH had higher SVCDI compared to those with early intraoperative normotension among atrial fibrillation patients. In a large cohort study, Vignon P et al. compared several dynamic echocardiographic parameters for predicting fluid responsiveness and reported that the area under the ROC curve of SVC-DI (0.75) was significantly greater than that of IVCmax (0.63) and PPV (0.67) in mechanically ventilated patients\u003csup\u003e[\u003c/sup\u003e\u003csup\u003e26\u003c/sup\u003e\u003csup\u003e]\u003c/sup\u003e. The optimal cutoff for SVC-DI was 21%, with a sensitivity of 61% and specificity of 84%. It has been demonstrated that venous collapsibility in the great veins results from systemic filling pressure-driven venous return, rather than aortic pressure transmission\u003csup\u003e[27\u003c/sup\u003e\u003csup\u003e\u0026ndash;\u003c/sup\u003e\u003csup\u003e29]\u003c/sup\u003e. Charbonneau et al. found that in mechanically ventilated septic patients, the SVC demonstrated higher accuracy than the IVC in predicting fluid responsiveness. The threshold for SVC to predict fluid responsiveness was 29%, with a sensitivity of 54% and a specificity of 89%, while the threshold for IVC was 21%, with a sensitivity of 38% and a specificity of 61%\u003csup\u003e[\u003c/sup\u003e\u003csup\u003e30\u003c/sup\u003e\u003csup\u003e]\u003c/sup\u003e. These results are largely consistent with some of our findings.Consequently, assessing the vena cava collapsibility/distensibility index is clinically valuable for predicting hypotension. Even in the presence of AF, IVC-CI and SVC-DI can still serve as predictive indicators for hypotension during general anesthesia.\u003c/p\u003e\n\u003cp\u003eThere are some limitations of our study. A relatively small number of patients were included, although the estimated power of the study was sufficient to detect significant reliable results. The study participants were elderly patients with relatively unstable hemodynamics. These patients were administered various types of oral medications preoperatively, primarily including ventricular rate-controlling medications and antihypertensive medications, which may have affected the validity of the analysis at the extremes of collapsibility index. The relationship between preoperative oral administration of different medications and the magnitude of blood pressure reduction following induction and during the early intraoperative period requires more diverse clinical settings to validate and further develop the findings of this study.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn AF patients, IVCCI and SVCDI can predict the occurrence of PIH and eIOH, preoperative IVCCI\u0026gt;34.1% indicates a non-invasive predictor of PIH; SVCDI\u0026gt;17.8% suggest reliable predictors of eIOH.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003ePIH: Post-induction hypotension; eIOH: Early intraoperative hypotension; IVCmax: Maximum inferior vena cava diameter; IVCmin: minimum inferior vena cava diameter; SVCmax: Maximum superior vena cava diameter; SVCmin: Minimum superior vena cava diameter; IVC-CI: Collapsibility index of inferior vena cava; SVC-DI: Distensibility index of superior vena cava; ROC: Receiver Operating Characteristics; MAP: Mean artery pressure.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors’ contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eXML: design the project; GSY, SWH, CHZ, collected the data; GSY, JZ analyzed and interpreted the data; XML wrote the manuscript; HJL and JZ critical revised the manuscript; All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study and publication of the manuscript was supported by the Shanghai Medical Innovation \u0026amp; Development Foundation (SMIDF2024-128-4).\u003c/p\u003e\n\u003cp\u003eMedical Application Foundation of Suzhou (SKY2021042).\u003c/p\u003e\n\u003cp\u003ePudong New District Health Commission Key Discipline Cluster for Cardiovascular Diseases Development Program (PWZxq2022-11).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and analyzed during the current study are available from the corresponding author in response to reasonable requests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the\u0026nbsp;Institutional Ethics Committee of Shanghai Zhoupu Hospital (Ethical number: 2022-C-027-E0)\u0026nbsp;and registered in Chinese Clinical Trial Register (registration number:\u0026nbsp;ChiCTR2300072846).\u0026nbsp;The study was also conformed to the ethical standards for medical research involving human subjects, as laid out in the 1964 Declaration of Helsinki and its later amendments.Written informed consent was obtained from each participant.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003ePublisher\u0026rsquo;sNote\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eShi S, Tang Y, Zhao Q, et al. Prevalence and risk of atrial fibrillation in China: a national cross-sectional epidemiological study. Lancet Regional Health-Western Pacific 2022; 100439.\u003c/li\u003e\n\u003cli\u003eMasoudi FA, Calkins H, Kavinsky CJ, et al. 2015 ACC/HRS/SCAI left atrial appendage occlusion device societal overview. J Am Coll Cardiol 2015; 66:1497-513.\u003c/li\u003e\n\u003cli\u003evan Waes JA, van Klei W A, Wijeysundera DN, et al. Association between intraoperative hypotension and myocardial injury after vascular surgery. Anesthesiology 2016; 124:35\u0026ndash;44.\u003c/li\u003e\n\u003cli\u003eBijker JB, van Klei W A, Vergouwe Y, et al. Intraoperative hypotension and 1-year mortality after noncardiac surgery. Anesthesiology 2009; 111:1217\u0026ndash;26.\u003c/li\u003e\n\u003cli\u003eWalsh M, Devereaux PJ, Garg AX, et al. Relationship between intraoperative mean arterial pressure and clinical outcomes after noncardiac surgery: toward an empirical definition of hypotension. Anesthesiology 2013; 119:507\u0026ndash;15.\u003c/li\u003e\n\u003cli\u003eLienhart A, Auroy Y, Pequignot F, et al. Survey of anesthesia-related mortality in France. Anesthesiology 2006; 105:1087\u0026ndash;97.\u003c/li\u003e\n\u003cli\u003eReich DL, Hossain S, Krol M, et al. Predictors of hypotension after induction of general anesthesia. Anesth Analg 2005; 101:622\u0026ndash;6.\u003c/li\u003e\n\u003cli\u003eS\u0026uuml;dfeld S, Brechnitz S, Wagner JY, et al. Post-induction hypotension and early intraoperative hypotension associated with general anaesthesia. Br J Anaesth 2017; 119:57\u0026ndash;64.\u003c/li\u003e\n\u003cli\u003eKalantari K, Chang JN, Ronco C, et al. Assessment of intravascular volume status and volume responsiveness in critically ill patients. Kidney int 2013; 83:1017\u0026ndash;28.\u003c/li\u003e\n\u003cli\u003ePeacock WF, soto KM. Current techniques of fluid status assessment. Contrib Nephrol 2010; 164:128\u0026ndash;42.\u003c/li\u003e\n\u003cli\u003e\u0026Ccedil;elebi Yamanoğlu NG, Yamanoğlu A, Parlak İ, et al. The role of inferior vena cava diameter in volume status monitoring; the best sonographic measurement method. Am J Emerg Med 2015; 33(3): 433-8.\u003c/li\u003e\n\u003cli\u003eZhang J, Critchley LA. Inferior Vena Cava Ultrasnography before General Anesthesia Can Predict Hypotension after Induction. Anesthesiology 2016; 124(3): 580-9.\u003c/li\u003e\n\u003cli\u003eEysenck W, Ammar A, Kanthasamy V, et al. A trial of three non-invasive blood pressure monitors compared with invasive blood pressure assessment in atrial fibrillation and sinus rhythm. Int J Clin Pract 2019; 13410.\u003c/li\u003e\n\u003cli\u003eZhang J, Critchley LA. Inferior vena cava ultrasonography before general anesthesia can predict hypotension after induction. Anesthesiology 2016; 124:580-9.\u003c/li\u003e\n\u003cli\u003eMitchell C, Rahko PS, Blauwet LA, et al. Guidelines for Performing a Comprehensive Transthoracic Echocardiographic Examination in Adults: Recommendations from the American Society of Echocardiography. American Society Echocardiogrphy 2019; 32:1-64.\u003c/li\u003e\n\u003cli\u003eMantovani MM, Fantoni DT, Gimenes AM, et al. Clinical monitoring of cardiac output assessed by transoesophageal echocardiography in anesthetised dogs: a comparison with the thermodilution technique. Biomedical Chromatogaphy 2017; 13(1):325.\u003c/li\u003e\n\u003cli\u003eFutier E, Lefrant JY, Guinot PG, et al. Effect of individualized vs standard blood pressure management strategies on postoperative organ dysfunction among high-risk patients undergoing major surgery: A Randomized Clinical Trial. JAMA. 2017, 318(14): 1346-57.\u003c/li\u003e\n\u003cli\u003eTuran A, Chang C, Cohen B, et al. Incidence, severity, and detection of blood pressure perturbations after abdominal surgery: A prospective blinded observational study. Anesthesiology 2019; 130(4):550-9.\u003c/li\u003e\n\u003cli\u003eDeLong eR, DeLong DM, Clarke-Pearson DL. Comparing the areas under two or more correlated receiver operating characteristic curves: A nonparametric approach. Biometrics 1988; 44:837\u0026ndash;45.\u003c/li\u003e\n\u003cli\u003eM\u0026ouml;ller Petrun A, Kamenik M. Bispectral index-guided induction of general anesthesia in patients undergoing major abdominal surgery using propofol or etomidate: a double-blind, randomized, clinical trial. British Journal of Anesthesia 2013; 110(3): 388-96.\u003c/li\u003e\n\u003cli\u003eGreen RS, Butler MB. Post-intubation hypotension in general anesthesia: A retrospective analysis. Journal Intensive Care Medicine 2016; 31(10): 667-75.\u003c/li\u003e\n\u003cli\u003eEichenlaub M, Mueller-Edenborn B, Minners J, et al. Left atrial hypertension, electrical conduction slowing, and mechanical dysfunction: The pathophysiological triad in atrial fibrillation-associated atrial cardiomyopathy. Front Physiol 2021; 12: 670527.\u003c/li\u003e\n\u003cli\u003eBortolotti P, Colling D, Colas V, et al. Respiratory changes of the inferior vena cava diameter predict fluid responsiveness in spontaneously breathing patients with cardiac arrhythmias. Annals of Intensive Care 2018; 8(1): 79. \u003c/li\u003e\n\u003cli\u003eCowie BS, Kluger R, Rex S, et al. The relationship between superior vena cava diameter and collapsibility and central venous pressure. Anesthesia Intensive Care 2015; 43(3): 357-60.\u003c/li\u003e\n\u003cli\u003eCioccari L, Baur HR, Berger D, et al. Hemodynamic assessment of critically ill patients using a miniaturized transesophageal echocardiography probe. Critical Care 2013; 17(3):121.\u003c/li\u003e\n\u003cli\u003eVignon P, Repess\u0026eacute; X, B\u0026eacute;got E, et al. Comparison of echocardiographic indices used to predict fluid responsiveness in ventilated patients. American Journal of Respiratory Critical Care Medicine 2017; 195:1022-32.\u003c/li\u003e\n\u003cli\u003eNakamura K, Tomida M, Ando T, et al. Cardiac variation of inferior vena cava: new concept in the evaluation of intravascular blood volume. Journal Medical Ultrasonics 2013; 40:205-9.\u003c/li\u003e\n\u003cli\u003eNakamura K, Qian K, Ando T, et al. Cardiac variation of internal jugular vein for the evaluation of hemodynamics. Ultrasound In Medicine and Biology 2016; 42: 1764-70. \u003c/li\u003e\n\u003cli\u003eDeng Y, Dong J, Zhou J, et al. Dynamic assessment of the central vein throughout the cardiac cycle in adults with no right heart disease by cardiac CT. Clinical Imaging 2021; 69:120-5.\u003c/li\u003e\n\u003cli\u003eCharbonneau H, Riu B, Faron M, et al. Predicting preload responsiveness using simultaneous recordings of inferior and superior vena cava diameters. Critical Care 2014; 18(5):473.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"IVC-CI, SVC-DI, atrial fibrillation, post-induction hypotension, early intraoperative hypotension ","lastPublishedDoi":"10.21203/rs.3.rs-6444922/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6444922/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eAtrial fibrillation (AF) is a prevalent arrhythmia, the ineffective contraction of the atria leads to a decrease in effective cardiac output. AF patients are prone to hypotension during anesthesia, especially in the early stages of general anesthesia. We explored whether the inferior vena cava collapsibility index (IVCCI) or the superior vena cava distensibility index (SVCDI) could predict the occurrence of post-induction hypotension (PIH) and early intraoperative hypotension (eIOH) in AF patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eA total of 77 AF patients undergoing left atrial appendage occlusion under general anesthesia were included in this study. The inferior vena cava was measured before induction and the superior vena cava after induction. The main outcome was the ultrasound measurements of IVCCI and SVCDI in AF patients and theirassociation with hypotension during general anesthesia. Hypotension was classified as the mean arterial pressure (MAP) below 60 mmHg or more than 20% below the baseline level. The correlation between IVC-CI, SVC-DI and the percentage decrease in MAP was assessed. Receiver operating characteristic (ROC) curves of IVC-CI, SVC-DI were separately generated to predict PIH and eIOH. Logistic regression was employed to validate the risk factors for PIH and eIOH in AF patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eAF patients who developed PIH had a significantly higher IVCCI (P\u0026lt;0.001) and developed eIOH had a significantly higher SVCDI (P\u0026lt;0.001). ROC curve analysis showed that IVCCI had an accuracy of 85% to predict PIH at a cut-off point more than 34.1% (P\u0026lt;0.001). SVCDI had an accuracy of 86% to predict eIOH at a cut-off point more than 17.8% (P\u0026lt;0.001). After adjusting for confounding variables, IVCCI was an independent predictor of PIH (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.001), while SVCDI was an independent predictor of eIOH (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e Preoperative IVCCI\u0026gt;34.1% indicates a non-invasive predictor of PIH in AF patients; SVCDI\u0026gt;17.8% suggest a reliable predictor of eIOH in AF patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration: \u003c/strong\u003eThis trial was registered on June 27, 2023 at the China Clinical Trial Center (http://www.chictr.org.cn; No. ChiCTR2300072846).\u003c/p\u003e","manuscriptTitle":"Ultrasonography evaluation of the inferior vena cava collapsibility index and the superior vena cava distensibility index for predicting hypotension during general anesthesia in atrial fibrillation patients：a prospective observational study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-07 08:43:52","doi":"10.21203/rs.3.rs-6444922/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-07-07T09:13:24+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-05T18:10:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"17820747075627493752213391368666871712","date":"2025-07-04T03:32:20+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"293961133858662116739896960692631355643","date":"2025-07-02T10:02:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"120999677569580286856146033237009532343","date":"2025-07-02T04:23:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"12711091356182379482580415640201835285","date":"2025-06-12T10:41:20+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-27T02:34:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"164241715243361035970722588323214054901","date":"2025-05-21T01:37:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"45464731061919017795965496733185900426","date":"2025-04-30T16:35:18+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-29T06:49:28+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-29T06:46:46+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-04-28T04:46:56+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-28T01:22:04+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Anesthesiology","date":"2025-04-28T01:20:57+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8e00c4de-a730-49e2-b417-40102798e0ed","owner":[],"postedDate":"May 7th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-09-08T15:58:40+00:00","versionOfRecord":{"articleIdentity":"rs-6444922","link":"https://doi.org/10.1186/s12871-025-03295-5","journal":{"identity":"bmc-anesthesiology","isVorOnly":false,"title":"BMC Anesthesiology"},"publishedOn":"2025-09-01 15:57:01","publishedOnDateReadable":"September 1st, 2025"},"versionCreatedAt":"2025-05-07 08:43:52","video":"","vorDoi":"10.1186/s12871-025-03295-5","vorDoiUrl":"https://doi.org/10.1186/s12871-025-03295-5","workflowStages":[]},"version":"v1","identity":"rs-6444922","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6444922","identity":"rs-6444922","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}