The Correlation Between Myocardial Dysfunction and Age in Duchenne Muscular Dystrophy: Assessed by Cardiac Magnetic Resonance Tissue Tracking

The Correlation Between Myocardial Dysfunction and Age in Duchenne Muscular Dystrophy: Assessed by Cardiac Magnetic Resonance Tissue Tracking | 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 The Correlation Between Myocardial Dysfunction and Age in Duchenne Muscular Dystrophy: Assessed by Cardiac Magnetic Resonance Tissue Tracking Hui Liu, Hua-yan Xu, Hang Fu, Rong Xu, Liang-geng Gong, Ying-kun Guo This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7231467/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Backgro und: Duchenne muscular dystrophy (DMD) is a progressive disorder affecting skeletal muscles, the heart, the respiratory system, and the nervous system, with cardiovascular complications emerging as the primary cause of mortality in DMD patients. Objectives: This study aims to quantitatively assess myocardial strain in patients with DMD using cardiac magnetic resonance (CMR) tissue tracking technology. The study seeks to evaluate subclinical cardiac dysfunction and investigate variations in myocardial dysfunction across different age groups. Additionally, it aims to explore the correlation between myocardial strain parameters and myocardial fibrosis. Methods : Between August 2018 and January 2020, 110 DMD patients diagnosed at a pediatric neurology outpatient department were included in the study. The patients were categorized into three age groups: 1-6 years, 7-10 years, and 11-14 years. Based on left ventricular ejection fraction (LVEF), the patients were further divided into a normal LVEF group (LVEF ≥ 55%) and a decreased LVEF group (LVEF < 55%). Furthermore, based on the presence of delayed enhancement, patients were classified into late gadolinium enhancement (LGE) positive and LGE negative groups. Additionally, 69 healthy volunteers were recruited for comparison. In conclusion, parameters of left ventricular (LV) function, along with global and local myocardial strain parameters of the left ventricle, were assessed. These included radial, circumferential, and longitudinal peak strains at the base, middle, and apex of the left ventricle. Statistical analyses were conducted using the T-test. Results: In comparison to the control group (n = 21), the cardiac function and myocardial strain of patients aged 3-6 years (n = 15) did not exhibit any decline. LVEF (59.58 ± 7.09 vs 63.39 ± 5.27), left ventricular global radial (37.34 ± 9.78 vs 42.95 ± 9.22), circumferential (- 20.75 ± 3.77 vs -22.09 ± 2.46) and longitudinal (- 13.91 ± 2.81 vs -15.69 ± 2.52) strain and local strain parameters of DMD patients (n = 63) at the age of 7-10 years were lower than that of normal volunteers(n = 18) . With the increase of age, compared with normal volunteers(n = 22), patients with DMD at the age of 11-14 years old(n = 21) further expanded the range of local strain reduction in the left ventricle than those in the age group of 7-10 years, except for the reduction of LVEF (59.61 ± 9.27 vs 62.22 ± 3.93), left ventricular global radial (36.48 ± 10.22 vs 41.82 ± 8.38), circumferential (- 19.49 ± 4.13 vs -21.97 ± 2.37) and longitudinal (- 12.59 ± 2.38 vs -14.51 ± 2.16) were all decreased. The number of the decreased local strain parameters were more than 7-10 years patients. For patients in LVEF preserved group(n = 77), even if there was no significant difference in cardiac function between LVEF preserved group and normal control group (61.37 ± 6.06 vs 62.74 ± 4.48), the global and local myocardial strain of left ventricle had decreased in different degree. LGE negative patients (n = 51)showed a decrease in global and local myocardial strain without a decrease in cardiac function (60.89 ± 6.42 vs 62.74 ± 4.48). Conclusions: In patients with DMD, myocardial dysfunction predominantly manifests in children older than seven years, exhibiting a subtle progression that exacerbates with advancing age. The myocardial injury tends to develop from the basal epicardium towards the apical and endocardial regions. CMR tissue tracking offers an earlier assessment of cardiac dysfunction in DMD patients compared to traditional parameters such as LVEF and LGE. Duchenne Muscular Dystrophy Magnetic Resonance Imaging Tissue tracking Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Duchenne muscular dystrophy (DMD) is a disorder that affects the skeletal muscles, heart, respiratory, and nervous systems. It is the most prevalent and severe form of progressive muscular dystrophy. Epidemiological data indicate that approximately one in every 3,500 to 5,000 males globally is affected by DMD [ 1 ]. The life expectancy for most individuals with DMD is limited to 20–30 years, with cardiovascular complications being the leading cause of mortality [ 2 ]. The assessment of myocardial injury is challenging due to the absence of validated cardiac imaging biomarkers. Furthermore, evaluating cardiac function using traditional New York Heart Association (NYHA) classifications is problematic, as patients exhibit significantly reduced motor function, and the symptoms and signs of heart failure are often subtle [ 3 ]. Currently, there is a paucity of effective methods for the early detection of cardiac dysfunction and myocardial injury in DMD. Echocardiography and cardiac magnetic resonance (CMR) are the primary imaging modalities recommended by clinical guidelines for the detection of cardiac complications. Although echocardiography is a simple, rapid, and widely utilized technique, it is susceptible to limitations related to the acoustic window and operator dependency. Simultaneously, patients with DMD frequently exhibit chest wall abnormalities and scoliosis, complicating echocardiographic diagnosis due to challenges related to acoustic windows and body positioning [ 4 ]. CMR tissue tracking, also referred to as myocardial strain analysis, leverages existing cardiac cine sequences for advanced post-processing beyond conventional cardiac function assessments, such as ejection fraction, thereby providing additional parameters for evaluating cardiac function. The myocardial strain assessed via tissue tracking technology encompasses three directions: longitudinal, radial, and circumferential, corresponding to the movement of the sub-endocardial, mid-myocardial, and sub-epicardial layers, respectively. This technique allows for the simultaneous evaluation of both local and global myocardial deformation, thereby facilitating the detection of subclinical cardiac dysfunction [ 5 ]. In recent years, tissue tracking technology has been applied to both ischemic cardiomyopathy [ 6 ][ 7 ] and non-ischemic cardiomyopathies, including hypertrophic cardiomyopathy [ 8 ], dilated cardiomyopathy [ 9 ], restrictive cardiomyopathy [ 10 ], right ventricular arrhythmogenic cardiomyopathy [ 11 ], and neuromuscular diseases [ 12 ]. In the initial stages of research, certain scholars employed CMR tissue tracking technology to investigate myocardial strain in patients with DMD. Siegel et al reported that myocardial strain in DMD patients was significantly reduced compared to a normal control group, and that myocardial strain in patients with myocardial fibrosis was markedly lower than in those without fibrosis [ 13 ]. Myocardial fibrosis represents an advanced stage of disease progression, which is challenging to reverse once it has developed. Consequently, it is crucial to detect subclinical myocardial injury prior to the onset of myocardial fibrosis through the use of tissue tracking technology. This study aims to quantitatively assess myocardial strain in DMD patients at an early stage of the disease using CMR tissue tracking technology. It seeks to evaluate subclinical cardiac dysfunction and investigate the variations in myocardial dysfunction across different age groups of patients for the first time. Additionally, the study intends to explore the myocardial strain parameters in relation to myocardial fibrosis. Methods Study population Between August 2018 and January 2020, a total of 110 cases of DMD were identified in the pediatric neurology outpatient department. All patients included in the study satisfied the diagnostic criteria established by the 2010 American Duchenne Muscular Dystrophy Nursing Attention Working Group [ 14 ]. The screening process involved children who met at least one of the following three criteria: (1) abnormal muscle function in male children, irrespective of family history; (2) significantly elevated serum creatine kinase levels, with other related diseases ruled out; and (3) elevated levels of transaminases, specifically aspartate transaminase and alanine transaminase. Confirmation of DMD was achieved through the detection of mutations or deletions in the DMD gene via blood cell genetic analysis. The exclusion criteria encompassed the presence of other cardiovascular diseases (such as congenital heart disease or cardiomyopathy) (n = 0), contraindications for CMR examination (n = 0), and poor image quality (n = 11).Ultimately, 99 patients were included in the final analysis. The patients were categorized into three age groups: 3–6 years, 7–10 years, and 11–14 years. Based on left ventricular ejection fraction (LVEF), DMD were classified into two groups: the LVEF normal group (LVEF ≥ 55%) and the LVEF decreased group (LVEF < 55%). Furthermore, patients were divided into two groups based on the presence of delayed enhancement: the Late gadolinium enhancement (LGE) positive group and the LGE negative group. A total of 69 normal volunteers were recruited. For children unable to cooperate, chloral hydrate was administered, with guardian consent, to induce a sleep state for examination. Inclusion criteria for the study were as follows: male children aged 3–14 years, absence of cardiac symptoms, no history of heart disease or other chronic illnesses, and no congenital, hereditary, or acquired neuromuscular disorders. Exclusion criteria for normal volunteers included contraindications (n = 0) and poor quality of CMR imaging (n = 9). Finally, 60 normal volunteers were included. This study was approved by China registered clinical trial Ethics Committee (chierct-20180107) and registered in China clinical trial registry (chictr180018340). All legal guardians of the subjects have signed informed consent forms. Biomarkers Age, height, weight, body surface area and body mass index were recorded. The results of electrocardiogram and gene detection were recorded. Venous blood was collected from patients with DMD to obtain the results of creatine kinase myocardial isoenzyme, creatine phosphokinase, troponin I and myoglobin . CMR imaging protocol The patients with DMD and the control group were scanned with 3.0T MRI (skyra, Siemens Medical Solutions, Erlangen, Germany).The contraindications of patients and healthy volunteers were excluded before scanning: 1) Ferromagnetic metal foreign bodies in the body; 2) Patients with claustrophobia, allergic constitution or recent allergic diseases such as measles and allergic dermatitis; 3) Contraindications of gadolinium contrast agent: estimated glomerular filtration rate (eGFR) < 30 ml / min / 1.73 m2. At the same time, patients and volunteers were given breathing training to obtain good image quality. Patients in a state of sleep were examined while breathing naturally. The head advanced scanning mode was adopted. The children were lying on the scan bed with 18 channel body coil. Electrocardiogramelectrode was connected and electrocardiogramgated touch was used to send acquisition signal. During the examination, electrocardiogramand respiratory gating were used to observe the patient's condition. Firstly, the two chamber, four chamber and three chamber images of the heart were obtained by automatic scanning. Based on the location image, bSSFP sequence (TR 3.42 ms,TE1.48 ms, FA 34 °, slice thickness 6 mm, FOV 300 × 241 mm 2 , matrix size 224 × 126) was used to collect the cardiac cine imaging. The scanning range completely covers the left ventricular. A total of 11–12 short axis, four and two cavity heart cine images are scanned simultaneously, each layer contains 25 phases. Gadolinium-enhanced images were acquired in the same sections as the cine images 10 minutes after intravenous injection of gadopentetate dimeglumine (dose: 0.1 ml/kg body weight, flow rate:1.0–2.0 ml/s, MultiHance 0.5 mmol/ml; Bracco, Milan, Italy) using an inversion recovery True FISP sequence (TR/TE700/1.31 ms, flip angle 20°, FOV 320 mm × 270 mm 2 , and slice thickness 6 mm). All healthy volunteers did not undergo enhanced scanning. Imaging analysis The myocardial strain images were processed and analyzed using the Cvi42 (cmr42, Circle Cardiovascular Imaging Inc., California, Canada) software. The procedure was as follows: the short-axis cine images were imported into the short-3D module. Experienced radiologists manually delineated the endocardial and epicardial borders at end-systole and end-diastole. The software then computed left ventricular functional parameters, including left ventricular end-systolic volume, left ventricular end-diastolic volume, LVEF, left ventricular mass, and other measurement parameters. Subsequently, the short-axis, four-chamber, and two-chamber cine sequences were imported into the tissue tracking module. The endocardium and epicardium at end-systole and end-diastole of the short axis were manually delineated layer by layer. Positioning points were placed at the insertion points of the interventricular septum for segmental positioning and voxel point calibration (Fig. 1 ). Subsequently, the end-diastolic epicardium and epicardium of both four-chamber and two-chamber heart views were delineated, with the positioning line extending from the mitral orifice to the apex. The global and regional myocardial strain parameters of the left ventricle were then assessed, encompassing the radial, circumferential, and longitudinal peak strains at the base, mid, and apical segments of the left ventricle(Fig. 2 ). In this analysis, the end-diastolic myocardial voxel position serves as the reference point, with peak displacement indicating the maximum percentage distance traversed by left ventricular myocardial pixels throughout the cardiac cycle, expressed as a percentage. Ventricular wall thickening is denoted as positive, while myocardial shortening is indicated as negative [ 15 ]. Radial strain is assigned a positive value, whereas circumferential and longitudinal strains are assigned negative values. The presence of delayed enhancement is evaluated by one intermediate and one senior physician. In cases of disagreement, a third senior physician provides confirmation. Statistics analysis SPSS (version 25.0, IBM SPSS Inc., Chicago, IL, USA) and R Studio (version Version 1.3.959) were used for analysis. Kolmogorov – Smirnov test was used to test whether the parameters were normal distribution.The data are expressed as mean and standard deviation (SD) or median and interquartile range (IQR, 25% – 75%). Levene's test was used to test the homogeneity of variance. T test was used when the parameters of DMD patients and volunteers conformed to the normal distribution and the variance was homogeneous. If not, the non-parametric test was used. P < 0.05 showed that the difference was statistically significant. Result Baseline data and cardiac function According to the inclusion and exclusion criteria, 99 DMD patients (8 ± 2 years old) and 61 healthy volunteers (8 ± 3years old)were included (Table 1 ). There was no significant difference in age and body mass index between DMD patients and normal control group, but the heart rate of DMD patients was significantly higher than that of normal control group. Among 99 patients with DMD, 84 (84.8%) belonged to DMD gene fragment deletion, 11 (11.1%) belonged to DMD gene repeat mutation, and 4 (4.1%) belonged to DMD gene point mutation. Among them, 7 patients lost walking ability completely. All patients were treated with glucocorticoids. In terms of cardiac function, the LVEF, the global radial (37.05 ± 10.14 vs 40.37 ± 8.52), circumferential (-20.30 ± 5.85 vs -21.37 ± 3.56) and longitudinal (− 13.57 ± 2.81 vs-14.86 ± 2.34) strain of the left ventricle decreased significantly (Fig. 3 ). According to segmental analysis of left ventricular strain, we found that radial (46.93 ± 13.47 vs 55.43 ± 13.13) and circumferential (− 16.18 ± 3.15 vs-18.08 ± 1.96) strain at the base of the left ventricle decreased significantly. The radial (35.37 ± 11.36 vs 40.23 ± 10.93), circumferential (− 20.48 ± 3.89 vs-22.08 ± 2.83) and longitudinal (− 12.39 ± 3.38 vs-14.09 ± 2.83) strain at the middle all decreased significantly. The circumferential (− 12.39 ± 3.38 vs-14.09 ± 2.83) strain (-23.70 ± 5.85 vs -25.37 ± 3.65) and longitudinal (− 16.61 ± 2.46 vs-17.97 ± 2.05) strain at the apex decreased significantly (Table 1 ). Table 1 Baseline characteristics and CMR parameters of study population Healthy group (N = 61) DMD group (N = 99) Age 8 ± 3 8 ± 2 Male 61 99 Body mass index(kg/m 2 ) 17.92 ± 5.15 17.77 ± 3.83 Heart rate 86 ± 14 98 ± 16* Genetics Mutation - 4 Repetition - 11 Deletion - 84 Myocardial enzyme - Creatine kinase increased - 99 Creatine kinase isoenzyme increased - 99 Myoglobin increased - 99 Cardiac troponin increased - 25 Wheelchair - 7 Glucocorticoids - 99 LV function LV ejection fraction(%) 62.74 ± 4.48 58.73 ± 7.00* LV end-diastolic volume index (ml/m 2 ) 75.03 ± 12.63 73.27 ± 13.11 LV end-systolic volume index (ml/m 2 ) 29.81 ± 10.48 29.86 ± 13.03 LV stroke volume index (ml/m 2 ) 50.05 ± 17.28 43.29 ± 13.93* LV mass index (g/m 2 ) 0.56 ± 0.21 0.54 ± 0.11 RV function RV ejection fraction(%) 54.11 ± 6.01 51.93 ± 10.35 RV end-diastolic volume index (ml/m 2 ) 73.37 ± 15.34 62.32 ± 13.74* RV end-systolic volume index (ml/m 2 ) 34.62 ± 8.58 30.61 ± 7.72* Global Strain Global radial peak strain(%) 40.37 ± 8.52 37.05 ± 10.14* Global circumferential peak strain(%) -21.37 ± 3.56 -20.30 ± 5.85* Global longitudinal peak strain(%) -14.86 ± 2.34 -13.57 ± 2.81* Segment strain Basal radial peak strain(%) 55.43 ± 13.13 46.93 ± 13.47* Basal circumferential peak strain(%) -18.08 ± 1.96 -16.18 ± 3.15* Basal longitudinal peak strain(%) -11.38 ± 4.31 -12.14 ± 4.08 Middle radial peak strain(%) 40.23 ± 10.93 35.37 ± 11.36* Middle circumferential peak strain(%) -22.08 ± 2.83 -20.48 ± 3.89* Middle longitudinal peak strain(%) -14.09 ± 2.83 -12.39 ± 3.38* Apical radial peak strain(%) 32.66 ± 10.48 34.72 ± 16.77 Apical circumferential peak strain(%) -25.37 ± 3.65 -23.70 ± 5.85* Apical longitudinal peak strain(%) -17.97 ± 2.05 -16.61 ± 2.46* CMR: cardiac magnetic resonance, DMD:duchenne muscular dystrophy, *:P < 0.05. Comparison of left ventricular function, global and local myocardial strain at different age As shown in Table 2 , there was no significant difference in age, body mass index, LVEF, left ventricular end-diastolic volume index, left ventricular mass index, left ventricular global and local strain between 3-6-year-old DMD patients (n = 15) and normal volunteers (n = 21). Though there was no significant difference in age, BMI, left ventricular end-diastolic volume index, and left ventricular mass index between DMD patients (n = 63) and normal volunteers (n = 18) at the age of 7–10 years, LVEF (59.58 ± 7.09 vs 63.39 ± 5.27), left ventricular global radial (37.34 ± 9.78 vs 42.95 ± 9.22), circumferential (− 20.75 ± 3.77 vs -22.09 ± 2.46) and longitudinal (− 13.91 ± 2.81 vs -15.69 ± 2.52) strain was also lower than that of normal volunteers. Analyzing the local strain changes (Fig. 4 ), we found that the radial (47.82 ± 13.63 vs 60.08 ± 48.37) and circumferential strain (− 16.03 ± 2.78 vs -18.31 ± 1.37) of left ventricular basal segment, radial (36.24 ± 11.24 vs 43.40 ± 11.63), circumferential (− 20.75 ± 3.37 vs -22.65 ± 3.01) and longitudinal strain (− 12.48 ± 3.32 vs -15.41 ± 2.77) of left ventricular middle were significantly lower than those of normal control group. There was no decrease in three directions of apical segment. With the increase of age, compared with normal volunteers, patients with DMD at the age of 11–14 years old further expanded the range of local strain reduction in the left ventricle than those in the age group of 7–10 years, except for the reduction of LVEF (59.61 ± 9.27 vs 62.22 ± 3.93), left ventricular global radial (36.48 ± 10.22 vs 41.82 ± 8.38), circumferential (− 19.49 ± 4.13 vs -21.97 ± 2.37) and longitudinal (− 12.59 ± 2.38 vs -14.51 ± 2.16) were all decreased. Among the segments, the radial (43.84 ± 10.71 vs 55.64 ± 12.17) and circumferential (− 16.61 ± 3.17 vs -18.55 ± 1.41) strain at the left ventricular basal segment, the radial (32.46 ± 12.71 vs 42.43 ± 11.13) and circumferential (− 19.46 ± 4.51 vs -22.45 ± 2.34) strain at the middle segment, circumferential (− 22.80 ± 5.99 vs -25.99 ± 3.19) and longitudinal (− 15.54 ± 1.95 vs -17.98 ± 1.66) strain at the apical segment were all significantly reduced. Table 2 Comparison of CMR parameters between different age DMD groups Group 3–6 year 7–10 year 11–14 year Healthy group (N = 21) DMD group (N = 15) Healthy group (N = 18) DMD group (N = 63) Healthy group (N = 22) DMD group (N = 21) Age 5 ± 2 6 ± 1 8 ± 1 8 ± 1 12 ± 2 12 ± 1 Body mass index(kg/m 2 ) 16.45 ± 4.87 16.29 ± 1.39 18.66 ± 7.54 17.13 ± 3.38 18.71 ± 1.95 21.34 ± 4.80 LV function LV ejection fraction(%) 62.72 ± 4.46 59.60 ± 5.05 63.39 ± 5.27 59.58 ± 7.09* 62.22 ± 3.93 59.61 ± 9.27* LV end-diastolic volume index (ml/m 2 ) 73.37 ± 12.07 71.65 ± 10.19 71.49 ± 11.90 73.21 ± 14.19 79.51 ± 12.96 74.59 ± 11.88 LV end-systolic volume index (ml/m 2 ) 28.24 ± 5.62 29.48 ± 4.68 25.73 ± 5.68 30.37 ± 8.84 30.02 ± 5.95 32.23 ± 10.81 LV stroke volume index (ml/m 2 ) 33.91 ± 9.37 35.17 ± 7.44 49.17 ± 4.46 44.09 ± 13.90* 66.18 ± 12.40 52.70 ± 12.89* LV mass index (g/m 2 ) 1.06 ± 0.28 0.98 ± 0.20 0.55 ± 0.12 0.55 ± 0.89 0.60 ± 0.12 0.59 ± 0.15 Heart rate 92 ± 13 98 ± 10 88 ± 15 99 ± 17* 80 ± 13 93 ± 16* RV function RV ejection fraction(%) 53.03 ± 4.88 49.28 ± 9.71 56.15 ± 6.31 52.95 ± 11.54 53.48 ± 6.56 50.78 ± 6.12 RV end-diastolic volume index (ml/m 2 ) 67.67 ± 13.03 60.26 ± 12.07 70.77 ± 14.45 63.85 ± 13.48 80.93 ± 15.61 59.16 ± 15.44* RV end-systolic volume index (ml/m 2 ) 33.45 ± 8.37 31.06 ± 10.23 33.06 ± 6.54 30.62 ± 7.65 38.74 ± 9.16 30.23 ± 6.01* Global Strain Global radial peak strain(%) 36.63 ± 6.98 36.58 ± 9.02 42.95 ± 9.22 37.34 ± 9.78* 41.82 ± 8.38 36.48 ± 10.22* Global circumferential peak strain(%) -20.87 ± 2.70 -20.28 ± 3.61 -22.09 ± 2.46 -20.75 ± 3.77* -21.97 ± 2.37 -19.49 ± 4.13* Global longitudinal peak strain(%) -14.55 ± 2.28 -13.50 ± 3.24 -15.69 ± 2.52 -13.91 ± 2.81* -14.51 ± 2.16 -12.59 ± 2.38* Segment strain Basal radial peak strain(%) 51.21 ± 10.51 47.50 ± 16.30 60.08 ± 48.37 47.82 ± 13.63* 55.64 ± 12.17 43.84 ± 10.71* Basal circumferential peak strain(%) -17.39 ± 2.66 -16.19 ± 4.52 -18.31 ± 1.37 -16.03 ± 2.78* -18.55 ± 1.41 -16.61 ± 3.17* Basal longitudinal peak strain(%) -12.14 ± 3.94 -10.55 ± 5.67 -15.69 ± 2.52 -12.00 ± 4.22 -11.47 ± 4.56 -10.11 ± 3.14 Middle radial peak strain(%) 35.24 ± 8.54 35.74 ± 9.82 43.40 ± 11.63 36.24 ± 11.24* 42.43 ± 11.13 32.46 ± 12.71* Middle circumferential peak strain(%) -21.19 ± 3.05 -20.72 ± 3.39 -22.65 ± 3.01 -20.75 ± 3.37* -22.45 ± 2.34 -19.46 ± 4.51* Middle longitudinal peak strain(%) -13.62 ± 2.60 -12.68 ± 3.96 -15.41 ± 2.77 -12.48 ± 3.32* -13.45 ± 2.82 -11.89 ± 3.20 Apical radial peak strain(%) 30.04 ± 9.01 31.78 ± 11.31 32.92 ± 9.97 33.66 ± 15.42 34.93 ± 11.98 40.02 ± 22.61 Apical circumferential peak strain(%) -24.78 ± 3.34 -24.22 ± 4.08 -25.30 ± 4.26 -23.90 ± 6.20 -25.99 ± 3.19 -22.80 ± 5.99* Apical longitudinal peak strain(%) -17.62 ± 1.71 -16.51 ± 2.39 -18.36 ± 2.77 -16.98 ± 2.56 -17.98 ± 1.66 -15.54 ± 1.95* CMR: cardiac magnetic resonance, DMD:duchenne muscular dystrophy, *:Compared to healthy group of the same age group P < 0.05. Comparison of global and local myocardial strain in control group, LVEF preserved group and LVEF reduced group Of the 99 patients, 22 (22%) had decreased LVEF, and 77(78%) had preserved LVEF. Table 3 shows the comparison of left ventricular global and local myocardial strain among normal control group (mean age 8 ± 3 years), DMD patients in LVEF preserved group (mean age 8 ± 2 years) and DMD patients in LVEF declined group (mean age 9 ± 2 years). For patients in LVEF preserved group, even if there was no significant difference in cardiac function between LVEF preserved group and normal control group (61.37 ± 6.06 vs 62.74 ± 4.48), the global and local myocardial strain of left ventricle had decreased in different degree. The global longitudinal strain of left ventricle (− 13.74 ± 2.83 vs -14.86 ± 2.34) decreased significantly compared with the normal control group. For the left ventricular segments, radial (49.42 ± 13.67 vs 55.43 ± 13.13) and circumferential (− 16.50 ± 3.23 vs -18.08 ± 1.96) strain of left ventricular basal segment, longitudinal strain in the middle (− 12.41 ± 3.46 vs -14.09 ± 2.83) and apical (− 16.96 ± 2.37 vs -17.97 ± 2.05) segments decreased significantly in the LVEF preserved group. For patients with decreased LVEF, the global and local strain of left ventricle were further reduced than those with preserved LVEF. The global strain in three directions in the LVEF decreased group was significantly lower than that in the normal control group. Furthermore, the global radial strain in the LVEF decreased group was significantly lower than that in the preserved LVEF group. In segmental analysis, it was found that the radial (38.20 ± 8.29 vs 49.42 ± 13.67) and circumferential (− 15.06 ± 2.62 vs -16.50 ± 3.23) strain of basal segments, longitudinal strain of apical segment(− 16.36 ± 2.46 vs -16.96 ± 2.37) in LVEF decreased group were further lower than those in LVEF preserved group. Table 3 Comparison of CMR parameters between healthy, LVEF ≥ 55% DMD group and LVEF < 55% DMD group Healthy group (N = 61) LVEF ≥ 55% DMD group (N = 77) LVEF < 55% DMD group (N = 22) Age 8 ± 3 8 ± 2 9 ± 2* Body mass index(kg/m 2 ) 17.92 ± 5.15 17.82 ± 3.82 17.62 ± 3.95 LV function LV ejection fraction(%) 62.74 ± 4.48 61.37 ± 6.06 53.34 ± 7.84*# LV end-diastolic volume index (ml/m 2 ) 75.03 ± 12.63 71.82 ± 12.20 78.34 ± 15.13 LV end-systolic volume index (ml/m 2 ) 29.81 ± 10.48 26.73 ± 7.82 40.80 ± 20.25*# LV stroke volume index (ml/m 2 ) 50.05 ± 17.28 42.84 ± 13.49 44.91 ± 15.60 LV mass index (g/m 2 ) 0.56 ± 0.21 0.58 ± 0.14 0.53 ± 0.14 Heart Rate 86 ± 14 98 ± 17* 96 ± 16* RV function RV ejection fraction(%) 54.11 ± 6.01 53.49 ± 10.13 46.49 ± 9.45* RV end-diastolic volume index (ml/m 2 ) 73.37 ± 15.34 63.11 ± 13.40 59.51 ± 14.88* RV end-systolic volume index (ml/m 2 ) 34.62 ± 8.58 29.76 ± 7.22* 33.57 ± 8.83 Global Strain Global radial peak strain(%) 40.37 ± 8.52 39.01 ± 9.63 30.20 ± 9.00*# Global circumferential peak strain(%) -25.37 ± 3.56 -20.76 ± 3.05 -17.83 ± 3.74* Global longitudinal peak strain(%) -14.86 ± 2.34 -13.74 ± 2.83* -12.97 ± 2.75* Segment strain Basal radial peak strain(%) 55.43 ± 13.13 49.42 ± 13.67* 38.20 ± 8.29*# Basal circumferential peak strain(%) -18.08 ± 1.96 -16.50 ± 3.23* -15.06 ± 2.62*# Basal longitudinal peak strain(%) -11.38 ± 4.31 -11.44 ± 4.42 -11.16 ± 3.97 Middle radial peak strain(%) 40.23 ± 10.93 37.72 ± 10.83 27.15 ± 9.29* Middle circumferential peak strain(%) -22.08 ± 2.83 -21.19 ± 3.41 -17.97 ± 4.47* Middle longitudinal peak strain(%) -14.09 ± 2.83 -12.41 ± 3.46* -12.32 ± 3.14* Apical radial peak strain(%) 32.66 ± 10.48 35.47 ± 15.36 32.13 ± 21.18 Apical circumferential peak strain(%) -25.37 ± 3.65 -24.77 ± 4.29 -19.95 ± 8.64* Apical longitudinal peak strain(%) -17.97 ± 2.05 -16.96 ± 2.37* -16.36 ± 2.46*# CMR: cardiac magnetic resonance, DMD:duchenne muscular dystrophy, *:Compared to healthy volunteers P < 0.05, #: Compared to patients with LVEF ≥ 55. The difference in myocardial strain between LGE positive and LGE negative DMD patients As shown in Table 4 , 51 (52%) of 99 patients were found to be LGE positive by magnetic resonance delayed enhancement image. The average age of LGE positive patients was 9 ± 2 years old and that of LGE negative patients was 7 ± 2 years old. LGE positive patients were older than LGE negative patients (p < 0.05). The comparative study found that there was no significant difference in age between LGE negative patients and normal volunteers. LGE negative patients showed a decrease in global and local myocardial strain than normal group without a decrease in cardiac function (60.89 ± 6.42 vs 62.74 ± 4.48). The global longitudinal strain (− 13.64 ± 3.01 vs -14.86 ± 2.34), radial (48.52 ± 13.05 vs -55.43 ± 13.13) and circumferential (− 16.24 ± 3.42 vs -18.08 ± 1.96) strain of left ventricular basal segment, longitudinal strain of middle (− 12.43 ± 3.54 vs -14.09 ± 2.83) and apical (− 16.62 ± 2.57 vs -17.97 ± 2.05) segments were significantly lower than those of normal volunteers. Meanwhile, the LVEF of LGE positive patients was significantly lower than that of normal volunteers (58.19 ± 7.92 vs 60.89 ± 6.42) or LGE negative patients (58.19 ± 7.92 vs 62.74 ± 4.48). In terms of myocardial strain, LGE positive patients had more segments with reduced myocardial strain compared with controls. However, there was no significant difference in global and segments strain between LGE negative and LGE positive patients. Table 4 Comparison of CMR parameters between healthy, LGE negative DMD and LGE positive DMD group Healthy group (N = 61) LGE negative DMD group (N = 51) LGE positive DMD group(N = 48) Age 8 ± 3 7 ± 2 9 ± 2* Body mass index(kg/m 2 ) 17.92 ± 5.15 16.46 ± 2.66 19.15 ± 4.38# LV function LV ejection fraction(%) 62.74 ± 4.48 60.89 ± 6.42 58.19 ± 7.92*# LV end-diastolic volume index (ml/m 2 ) 75.03 ± 12.63 72.19 ± 11.54 74.42 ± 14.63 LV end-systolic volume index (ml/m 2 ) 29.81 ± 10.48 29.77 ± 6.36 26.93 ± 5.77 LV stroke volume index (ml/m 2 ) 50.05 ± 17.28 41.47 ± 15.38 45.24 ± 12.05 LV mass index (g/m 2 ) 0.56 ± 0.21 0.53 ± 0.11 0.57 ± 0.11 Heart Rate 86 ± 14 96 ± 15* 99 ± 18* RV function RV ejection fraction(%) 54.11 ± 6.01 53.07 ± 12.01 50.72 ± 8.21 RV end-diastolic volume index (ml/m 2 ) 73.37 ± 15.34 62.74 ± 13.24* 61.86 ± 14.37* RV end-systolic volume index (ml/m 2 ) 34.62 ± 8.58 30.48 ± 8.76* 30.75 ± 6.54* Global Strain Global radial peak strain(%) 40.37 ± 8.52 37.23 ± 10.43 36.86 ± 9.93 Global circumferential peak strain(%) -25.37 ± 3.56 -20.33 ± 3.10 -19.88 ± 3.75* Global longitudinal peak strain(%) -14.86 ± 2.34 -13.64 ± 3.01* -13.49 ± 2.62* Segment strain Basal radial peak strain(%) 55.43 ± 13.13 48.52 ± 13.05* 45.24 ± 13.85* Basal circumferential peak strain(%) -18.08 ± 1.96 -16.24 ± 3.42* -16.13 ± 2.88* Basal longitudinal peak strain(%) -11.38 ± 4.31 -11.42 ± 4.67 -11.34 ± 3.93 Middle radial peak strain(%) 40.23 ± 10.93 36.17 ± 11.22 34.52 ± 11.56* Middle circumferential peak strain(%) -22.08 ± 2.83 -20.81 ± 3.39 -20.18 ± 4.36* Middle longitudinal peak strain(%) -14.09 ± 2.83 -12.43 ± 3.54* -12.34 ± 3.23* Apical radial peak strain(%) 32.66 ± 10.48 32.65 ± 16.14 36.93 ± 17.30 Apical circumferential peak strain(%) -25.37 ± 3.65 -24.16 ± 4.00 -23.22 ± 7.35 Apical longitudinal peak strain(%) -17.97 ± 2.05 -16.62 ± 2.57* -16.59 ± 2.37* CMR: cardiac magnetic resonance, DMD:duchenne muscular dystrophy, LGE:late gadolinium enhancement, *:Compared to healthy volunteers P < 0.05, #: Compared to patients with negative LGE. Discussion In patients with DMD, gene mutations result in reduced synthesis of myotrophin, decreased stability of the dystrophin glycoprotein complex junction structure, increased fragility of cardiomyocyte myomembranes, significantly elevated intracellular calcium levels, damage to the myofiber membrane, and degeneration of myofibers [ 16 ], ultimately leading to myocardial systolic dysfunction. Our findings regarding myocardial systolic dysfunction are as follows: 1) In DMD children aged 1–6 years, there is no observed decrease in myocardial strain. However, in patients aged 7–10 years and 11–14 years, both global and regional myocardial strain of the left ventricle exhibit varying degrees of reduction, with a progression from the basal epicardium to the apical and endocardium. 2) We also conducted an analysis of the overall and regional myocardial strain in patients with both preserved and decreased LVEF. The results showed that the overall and local myocardial strain in patients with preserved LVEF was significantly lower than that in normal control group. 3) Among patients who are negative for LGE, there is no significant difference in LVEF compared to the control group. Nevertheless, the radial and circumferential strains at the base of the left ventricle, as well as the global longitudinal strain at the middle and apex, are significantly lower than those in normal controls. Research has demonstrated that as the disease progresses, extensive myocardial cell necrosis occurs, along with myocardial fat infiltration and fibrosis replacement, which contribute to cardiac remodeling and dysfunction [ 17 ]. This progression often culminates in late-stage heart failure, accompanied by life-threatening arrhythmias, ultimately resulting in cardiac death [ 18 ] [ 19 ]. The U.S. working group on nursing care for Duchenne muscular dystrophy has explicitly recommended proactive treatment for patients exhibiting reduced cardiac function or myocardial fibrosis. The guidelines further emphasize that interventions initiated only after clear evidence of myocardial injury are insufficient [ 3 ] [ 20 ]. Consequently, there is a pressing need for effective methods to detect myocardial injury early in pediatric patients. As early as 2005, researchers employed 1.5T magnetic resonance tagging technology to conduct cardiac imaging in a cohort of 13 patients with Duchenne muscular dystrophy, with an average age of 10.6 ± 3.01 years. The study revealed that, although the left ventricular volume and ejection fraction in patients with DMD were within normal ranges compared to the control group, there was a significant reduction in the overall circumferential strain of the ventricular base and middle layer [ 21 ]. Batra et al. also demonstrated a decline in circumferential strain in dystrophic myocardium, underscoring the importance of early and longitudinal cardiac function assessments in DMD to identify early biomarkers of cardiac dysfunction, which could inform the design of clinical trials aimed at mitigating cardiac pathology [ 22 ]. Consequently, it has been recognized that myocardial damage occurs much earlier than previously detected. However, the precise onset time in patients remains unclear. Building on the aforementioned research, we expanded the sample size and conducted a stratified analysis based on different age groups of children. Our findings indicated that children aged 3–6 years did not exhibit significant cardiac dysfunction. In contrast, children aged 7–10 years and 11–14 years showed varying degrees of reduction in overall and regional left ventricular strain. This discovery could enhance clinicians' ability to diagnose myocardial damage in DMD patients over the age of 7 years.This study significantly contributes to enhancing the diagnostic acumen of clinicians regarding myocardial damage in DMD patients over the age of seven. It offers a nuanced understanding of myocardial damage across various pediatric age groups and is anticipated to inform future expert consensus guidelines. The findings indicate that myocardial dysfunction in the basal region of the left ventricle among children aged 7–10 years is predominantly characterized by impaired radial and circumferential motion, suggesting subepicardial and intermediate myocardial injury in this region. This observation aligns with the myocardial fibrosis patterns identified through LGE imaging [ 23 ]. In patients aged 11–14, there is a noted decline in myocardial strain in both the basal and middle regions, accompanied by a reduction in longitudinal strain at the apex. This suggests a progression of myocardial dysfunction from the basal epicardium towards the apical and endocardial regions. Consistent with the findings of Lang et al [ 24 ], who reported severe cardiac dysfunction (LVEF < 55%) in approximately 18% of DMD patients, our study found that 22 out of 99 patients (22%) exhibited an LVEF below 55%. However, even among patients without overt cardiac dysfunction, myocardial strain abnormalities were evident. Hor et al. and Liu et al. have demonstrated that myocardial strain in patients with DMD who exhibit normal LVEF and negative LGE is significantly reduced compared to a control group [ 25 ][ 26 ]. In the present study, we have corroborated this finding through extensive research. These results underscore the limitations of relying solely on traditional indices, such as LVEF < 55% and positive LGE, to assess cardiac damage in DMD patients. CMR tissue tracking serves as a valuable adjunct to LVEF and LGE, facilitating the quantitative assessment of cardiac dysfunction and providing a robust foundation for early clinical intervention. However, this study has certain limitations. Firstly, the duration of the study was relatively short, and there was no long-term follow-up of the participants. Secondly, as a single-center study, the findings may not be entirely representative of data from other centers, although it is acknowledged that DMD is a rare condition. Nonetheless, the study's large sample size offers a significant advantage over many other studies, partially mitigating this limitation. Conclusion In patients with DMD, myocardial dysfunction predominantly manifests in children older than seven years, demonstrating progression and exacerbation with advancing age. The myocardial injury typically progresses from the basal epicardium towards the apical and endocardial regions. CMR tissue tracking offers an early assessment of cardiac dysfunction in DMD patients, providing earlier detection compared to conventional measures such as LVEF and LGE. Declarations Author Contribution Conception and design: H.L ,Y. G and L.Gong. Provision of study materials or patients: R. X, H. F.Collection and assembly of data: H.L and H. X.Data analysis and interpretation: H.L, R.X and H.F. Manuscript writing: H. L, Y.G and L. G. All authors contributed to the article and approved the submitted version. References Kamdar F, Garry DJ (2016) Dystrophin-Deficient Cardiomyopathy. J Am Coll Cardiol 67(21):2533–2546 Birnkrant DJ, Bushby K, Bann CM, DMD Care Considerations Working Group (2018) Diagnosis and management of Duchenne muscular dystrophy, part 1: diagnosis, and neuromuscular, rehabilitation, endocrine, and gastrointestinal and nutritional management. Lancet Neurol 17:251–267 McNally EM, Kaltman JR, Benson DW et al (2015) Contemporary cardiac issues in Duchenne muscular dystrophy. Working Group of the National Heart, Lung, and Blood Institute in collaboration with Parent Project Muscular Dystrophy. Circulation 131:1590–1598 Markham LW, Kinnett K, Wong BL et al (2008) Corticosteroid treatment retards development of ventricular dysfunction in Duchenne muscular dystrophy. Neuromuscul Disord 18:365–370 Claus P, Omar AMS, Pedrizzetti G et al (2015) Tissue tracking technology for assessing cardiac mechanics: principles, normal values, and clinical applications. JACC Cardiovasc Imaging 8(12):1444–1460 Schneeweis C, Qiu J, Schnackenburg B et al (2014) Value of additional strain analysis with feature tracking in dobutamine stress cardiovascular magnetic resonance for detecting coronary artery disease. J Cardiovasc Magn Reson 16:72 Brown J, Jenkins C, Marwick TH (2009) Use of myocardial strain to assess global left ventricular function: a comparison with cardiac magnetic resonance and 3-dimensional echocardiography. Am Heart J 157(1):1021–1025 Xu HY, Chen J, Yang ZG et al (2017) Early marker of regional left ventricular deformation in patients with hypertrophic cardiomyopathy evaluated by MRI tissue tracking: The effects of myocardial hypertrophy and fibrosis. J Magn Reson Imaging 46(5):1368–1376 Buss SJ, Breuninger K, Lehrke S et al (2015) Assessment of myocardial deformation with cardiac magnetic resonance strain imaging improves risk stratification in patients with dilated cardiomyopathy. Eur Heart J Cardiovasc Imaging 16(3):307–315 Dorbala S, Vangala D, Bruyere J et al (2014) Coronary microvascular dysfunction is related to abnormalities in myocardial structure and function in cardiac amyloidosis. JACC Heart Fail 2(4):358–367 Heermann P, Hedderich DM, Paul M et al (2014) Biventricular myocardial strain analysis in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) using cardiovascular magnetic resonance feature tracking. J Cardiovasc Magn Reson 16(1):75 Azzu A, Antonopoulos AS, Krupickova S et al (2023) Myocardial strain analysis by cardiac magnetic resonance 3D feature-tracking identifies subclinical abnormalities in patients with neuromuscular disease and no overt cardiac involvement. Eur Heart J Cardiovasc Imaging 24(4):503–511 Siegel B, Olivieri L, Gordish-Dressman H et al (2018) Myocardial Strain Using Cardiac MR Feature Tracking and Speckle Tracking Echocardiography in Duchenne Muscular Dystrophy Patients. Pediatr Cardiol 39(3):478–483 Bushby K, Finkel R, Birnkrant DJ et al (2010) Diagnosis and management of Duchenne muscular dystrophy, part 1: diagnosis, and pharmacological and psychosocial management. Lancet Neurol 9(1):77–93 Amaki M, Savino J, Ain DL et al (2014) Diagnostic concordance of echocardiography and cardiac magnetic resonance-based tissue tracking for differentiating constrictive pericarditis from restrictive cardiomyopathy. Circ Cardiovasc Imaging 7(5):819–827 Deconinck N, Dan B (2007) Pathophysiology of duchenne muscular dystrophy: current hypotheses. Pediatr Neurol 36(1):1–7 Starnes Joseph R, Weiner Jeffrey G, George-Durrett, Kristen et al (2024) Boys With Duchenne Muscular Dystrophy Have Diastolic Dysfunction Based on CMR.Circulation-Cardiovascular. Imaging 17(12):e017287. 10.1161/CIRCIMAGING.124.017287 Chenard AA, Becane HM, Tertrain F et al (1993) Ventricular arrhythmia in Duchenne muscular dystrophy: prevalence, significance and prognosis. Neuromuscul Disord 3:201–206 James KA, Gralla J, Ridall LA et al (2020) Left ventricular dysfunction in Duchenne muscular dystrophy. Cardiol Young :1–6 Duboc D, Meune C, Lerebours G et al (2005) Effect of perindopril on the onset and progression of left ventricular dysfunction in Duchenne muscular dystrophy. J Am Coll Cardiol 45:855–857 Ashford MW, Liu W, Lin SJ et al (2005) Occult cardiac contractile dysfunction in dystrophin-deficient children revealed by cardiac magnetic resonance strain imaging. Circulation 112(16):2462–2467 (25) Batra A, Barnard et al (2022) Longitudinal changes in cardiac function in Duchenne muscular dystrophy population as measured by magnetic resonance imaging. BMC Cardiovasc Disord 22(1):260. 10.1186/s12872-022-02688-5 Xu R, Xu H, Liu H et al (2020) The prevalence and natural progress of myocardial fibrosis in Duchenne muscular dystrophy patients. Eur Heart J 41(Supple2). 10.1093/ehjci/ehaa946.0214 Lang SM, Shugh S, Mazur W (2015) Myocardial Fibrosis and Left Ventricular Dysfunction in Duchenne Muscular Dystrophy Carriers Using Cardiac Magnetic Resonance Imaging. Pediatr Cardiol 36(7):1495–1501 Hor KN, Wansapura J, Markham LW et al (2009) Circumferential strain analysis identifies strata of cardiomyopathy in Duchenne muscular dystrophy: a cardiac magnetic resonance tagging study. J Am Coll Cardiol 53(14):1204–1210 Liu Z-Q, Maforo, Nyasha G et al (2024) MRI-Based Circumferential Strain in Boys with Early Duchenne Muscular Dystrophy Cardiomyopathy. Diagnostics 14(23). 10.3390/diagnostics14232673 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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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-7231467","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":494795874,"identity":"38231218-91aa-468a-9375-c1cdb3875ac6","order_by":0,"name":"Hui Liu","email":"","orcid":"","institution":"Second Affiliated Hospital of Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Hui","middleName":"","lastName":"Liu","suffix":""},{"id":494795875,"identity":"995f1129-78b7-4bf3-ba96-360ca78ea87b","order_by":1,"name":"Hua-yan Xu","email":"","orcid":"","institution":"West China Second University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hua-yan","middleName":"","lastName":"Xu","suffix":""},{"id":494795876,"identity":"82ebcee0-4225-4ac4-9c1e-368ccd52d0f3","order_by":2,"name":"Hang Fu","email":"","orcid":"","institution":"West China Second University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hang","middleName":"","lastName":"Fu","suffix":""},{"id":494795877,"identity":"d051e61c-cd7c-4b8e-a313-52ae90e444b8","order_by":3,"name":"Rong Xu","email":"","orcid":"","institution":"West China Second University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Rong","middleName":"","lastName":"Xu","suffix":""},{"id":494795878,"identity":"58f0258f-eeb0-4230-9765-ea6fb1b36538","order_by":4,"name":"Liang-geng Gong","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA10lEQVRIiWNgGAWjYLCCBAMJOX725gMHPlQQq+VBgYWxZM+xxIMzzhCpg/HBh4rEDTdyjA/zthChXN699/ALoMNAWj4c4G1gkOcXO4Bfi+GZc2kWQC3GM8+83XBAcgeD4czZCQS0zMgxMwBqke07nrvhgOEZYFDcJlILY8OBnAcHEtuI0CIvkWP8AKhFccKJHIYDB4nRYsBzxgwUL6BANjjYcEaCsF/k23uMP/74UweKysef/1TYyPNLE7LlAAObBBJfAqdKhC0NDMwfCCsbBaNgFIyCEQ0AgjZPRqQFEjYAAAAASUVORK5CYII=","orcid":"","institution":"Second Affiliated Hospital of Nanchang University","correspondingAuthor":true,"prefix":"","firstName":"Liang-geng","middleName":"","lastName":"Gong","suffix":""},{"id":494795879,"identity":"8b06e821-04ba-4e27-8259-6b8ce8a2af10","order_by":5,"name":"Ying-kun Guo","email":"","orcid":"","institution":"West China Second University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Ying-kun","middleName":"","lastName":"Guo","suffix":""}],"badges":[],"createdAt":"2025-07-28 08:23:45","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7231467/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7231467/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88409568,"identity":"de631666-8372-4599-bd33-875b69afc587","added_by":"auto","created_at":"2025-08-06 08:19:41","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1283573,"visible":true,"origin":"","legend":"\u003cp\u003eA schematic representation of myocardial strain analysis is presented. On the left, the operational interface of the analysis software is depicted. Myocardial strain parameters are derived by delineating the left ventricular endocardium and epicardium of the entire heart and identifying the insertion points of the anterior and posterior ventricular septum. The upper right illustration displays the strain parameters for each myocardial segment, while the lower right illustration shows the curve of longitudinal strain of the left ventricle throughout the cardiac cycle.\u003c/p\u003e","description":"","filename":"figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-7231467/v1/8c7b278a5e396626610f7aec.png"},{"id":88409565,"identity":"627b7591-1453-49e9-8577-58d5defd43a3","added_by":"auto","created_at":"2025-08-06 08:19:41","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":160910,"visible":true,"origin":"","legend":"\u003cp\u003eThe curve is a demonstration diagram of circumferential strain, including both global and local strain. The curve in the upper figure represents the time-strain curve of the global circumferential strain, while the curve in the lower figure represents the time-strain curves of different segments (basal, mid, and apical segments). The data at the bottom is a table generated by the system including global and local strain.\u003c/p\u003e","description":"","filename":"figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-7231467/v1/ffcd388dacf966096d103ab6.png"},{"id":88409569,"identity":"6407480f-2442-4e82-a2f2-14cc27d851f6","added_by":"auto","created_at":"2025-08-06 08:19:41","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1128604,"visible":true,"origin":"","legend":"\u003cp\u003eThe figure presented above illustrates the scatter plot distribution of global strain across radial, circumferential, and longitudinal directions, stratified by age groups. In contrast, the bar chart below provides a comparative analysis of global strain in these three directional components between healthy volunteers and patients with Duchenne Muscular Dystrophy (DMD). A red asterisk denotes a statistically significant difference between the two cohorts. Abbreviations used include GPSR for global longitudinal peak strain, GPSC for global radial peak strain, and GPSR for global circumferential peak strain.\u003c/p\u003e","description":"","filename":"figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-7231467/v1/fd298c9396ea32717514b315.png"},{"id":88411828,"identity":"93bf1b8f-1224-4f85-8e61-2676b2eca740","added_by":"auto","created_at":"2025-08-06 08:27:41","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1276384,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of strain parameters in three directions (radial, circumferential, and longitudinal direction) between healthy volunteers and DMD patients of different age groups and cardiac segments. PSL: longitudinal peak strain, PSC: radial peak strain, PSR:circumferential peak strain.\u003c/p\u003e","description":"","filename":"figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-7231467/v1/668a9a7d6487a5584787ee09.png"},{"id":91042498,"identity":"2afd0565-4967-4726-a48e-f1f69f2d98e2","added_by":"auto","created_at":"2025-09-11 04:31:42","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3947161,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7231467/v1/c3e10090-9a14-4923-bf12-e790e8db89b5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Correlation Between Myocardial Dysfunction and Age in Duchenne Muscular Dystrophy: Assessed by Cardiac Magnetic Resonance Tissue Tracking","fulltext":[{"header":"Introduction","content":"\u003cp\u003eDuchenne muscular dystrophy (DMD) is a disorder that affects the skeletal muscles, heart, respiratory, and nervous systems. It is the most prevalent and severe form of progressive muscular dystrophy. Epidemiological data indicate that approximately one in every 3,500 to 5,000 males globally is affected by DMD [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The life expectancy for most individuals with DMD is limited to 20–30 years, with cardiovascular complications being the leading cause of mortality [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The assessment of myocardial injury is challenging due to the absence of validated cardiac imaging biomarkers. Furthermore, evaluating cardiac function using traditional New York Heart Association (NYHA) classifications is problematic, as patients exhibit significantly reduced motor function, and the symptoms and signs of heart failure are often subtle [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Currently, there is a paucity of effective methods for the early detection of cardiac dysfunction and myocardial injury in DMD. Echocardiography and cardiac magnetic resonance (CMR) are the primary imaging modalities recommended by clinical guidelines for the detection of cardiac complications. Although echocardiography is a simple, rapid, and widely utilized technique, it is susceptible to limitations related to the acoustic window and operator dependency. Simultaneously, patients with DMD frequently exhibit chest wall abnormalities and scoliosis, complicating echocardiographic diagnosis due to challenges related to acoustic windows and body positioning [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. CMR tissue tracking, also referred to as myocardial strain analysis, leverages existing cardiac cine sequences for advanced post-processing beyond conventional cardiac function assessments, such as ejection fraction, thereby providing additional parameters for evaluating cardiac function. The myocardial strain assessed via tissue tracking technology encompasses three directions: longitudinal, radial, and circumferential, corresponding to the movement of the sub-endocardial, mid-myocardial, and sub-epicardial layers, respectively. This technique allows for the simultaneous evaluation of both local and global myocardial deformation, thereby facilitating the detection of subclinical cardiac dysfunction [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. In recent years, tissue tracking technology has been applied to both ischemic cardiomyopathy [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e][\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] and non-ischemic cardiomyopathies, including hypertrophic cardiomyopathy [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], dilated cardiomyopathy [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], restrictive cardiomyopathy [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], right ventricular arrhythmogenic cardiomyopathy [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], and neuromuscular diseases [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. In the initial stages of research, certain scholars employed CMR tissue tracking technology to investigate myocardial strain in patients with DMD. Siegel et al reported that myocardial strain in DMD patients was significantly reduced compared to a normal control group, and that myocardial strain in patients with myocardial fibrosis was markedly lower than in those without fibrosis [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Myocardial fibrosis represents an advanced stage of disease progression, which is challenging to reverse once it has developed. Consequently, it is crucial to detect subclinical myocardial injury prior to the onset of myocardial fibrosis through the use of tissue tracking technology. This study aims to quantitatively assess myocardial strain in DMD patients at an early stage of the disease using CMR tissue tracking technology. It seeks to evaluate subclinical cardiac dysfunction and investigate the variations in myocardial dysfunction across different age groups of patients for the first time. Additionally, the study intends to explore the myocardial strain parameters in relation to myocardial fibrosis.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cb\u003eStudy population\u003c/b\u003e\u003c/p\u003e\u003cp\u003eBetween August 2018 and January 2020, a total of 110 cases of DMD were identified in the pediatric neurology outpatient department. All patients included in the study satisfied the diagnostic criteria established by the 2010 American Duchenne Muscular Dystrophy Nursing Attention Working Group [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The screening process involved children who met at least one of the following three criteria: (1) abnormal muscle function in male children, irrespective of family history; (2) significantly elevated serum creatine kinase levels, with other related diseases ruled out; and (3) elevated levels of transaminases, specifically aspartate transaminase and alanine transaminase. Confirmation of DMD was achieved through the detection of mutations or deletions in the DMD gene via blood cell genetic analysis. The exclusion criteria encompassed the presence of other cardiovascular diseases (such as congenital heart disease or cardiomyopathy) (n = 0), contraindications for CMR examination (n = 0), and poor image quality (n = 11).Ultimately, 99 patients were included in the final analysis. The patients were categorized into three age groups: 3–6 years, 7–10 years, and 11–14 years. Based on left ventricular ejection fraction (LVEF), DMD were classified into two groups: the LVEF normal group (LVEF ≥ 55%) and the LVEF decreased group (LVEF \u0026lt; 55%). Furthermore, patients were divided into two groups based on the presence of delayed enhancement: the Late gadolinium enhancement (LGE) positive group and the LGE negative group. A total of 69 normal volunteers were recruited. For children unable to cooperate, chloral hydrate was administered, with guardian consent, to induce a sleep state for examination. Inclusion criteria for the study were as follows: male children aged 3–14 years, absence of cardiac symptoms, no history of heart disease or other chronic illnesses, and no congenital, hereditary, or acquired neuromuscular disorders. Exclusion criteria for normal volunteers included contraindications (n = 0) and poor quality of CMR imaging (n = 9).\u003c/p\u003e\u003cp\u003eFinally, 60 normal volunteers were included. This study was approved by China registered clinical trial Ethics Committee (chierct-20180107) and registered in China clinical trial registry (chictr180018340). All legal guardians of the subjects have signed informed consent forms.\u003c/p\u003e\u003cp\u003e\u003cb\u003eBiomarkers\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAge, height, weight, body surface area and body mass index were recorded. The results of electrocardiogram and gene detection were recorded. Venous blood was collected from patients with DMD to obtain the results of creatine kinase myocardial isoenzyme, creatine phosphokinase, troponin I and myoglobin .\u003c/p\u003e\u003cp\u003e\u003cb\u003eCMR imaging protocol\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe patients with DMD and the control group were scanned with 3.0T MRI (skyra, Siemens Medical Solutions, Erlangen, Germany).The contraindications of patients and healthy volunteers were excluded before scanning: 1) Ferromagnetic metal foreign bodies in the body; 2) Patients with claustrophobia, allergic constitution or recent allergic diseases such as measles and allergic dermatitis; 3) Contraindications of gadolinium contrast agent: estimated glomerular filtration rate (eGFR) \u0026lt; 30 ml / min / 1.73 m2. At the same time, patients and volunteers were given breathing training to obtain good image quality. Patients in a state of sleep were examined while breathing naturally. The head advanced scanning mode was adopted. The children were lying on the scan bed with 18 channel body coil. Electrocardiogramelectrode was connected and electrocardiogramgated touch was used to send acquisition signal. During the examination, electrocardiogramand respiratory gating were used to observe the patient's condition. Firstly, the two chamber, four chamber and three chamber images of the heart were obtained by automatic scanning. Based on the location image, bSSFP sequence (TR 3.42 ms,TE1.48 ms, FA 34 °, slice thickness 6 mm, FOV 300 × 241 mm\u003csup\u003e2\u003c/sup\u003e, matrix size 224 × 126) was used to collect the cardiac cine imaging. The scanning range completely covers the left ventricular. A total of 11–12 short axis, four and two cavity heart cine images are scanned simultaneously, each layer contains 25 phases. Gadolinium-enhanced images were acquired in the same sections as the cine images 10 minutes after intravenous injection of gadopentetate dimeglumine (dose: 0.1 ml/kg body weight, flow rate:1.0–2.0 ml/s, MultiHance 0.5 mmol/ml; Bracco, Milan, Italy) using an inversion recovery True FISP sequence (TR/TE700/1.31 ms, flip angle 20°, FOV 320 mm × 270 mm\u003csup\u003e2\u003c/sup\u003e, and slice thickness 6 mm). All healthy volunteers did not undergo enhanced scanning.\u003c/p\u003e\u003cp\u003e\u003cb\u003eImaging analysis\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe myocardial strain images were processed and analyzed using the Cvi42 (cmr42, Circle Cardiovascular Imaging Inc., California, Canada) software. The procedure was as follows: the short-axis cine images were imported into the short-3D module. Experienced radiologists manually delineated the endocardial and epicardial borders at end-systole and end-diastole. The software then computed left ventricular functional parameters, including left ventricular end-systolic volume, left ventricular end-diastolic volume, LVEF, left ventricular mass, and other measurement parameters. Subsequently, the short-axis, four-chamber, and two-chamber cine sequences were imported into the tissue tracking module. The endocardium and epicardium at end-systole and end-diastole of the short axis were manually delineated layer by layer. Positioning points were placed at the insertion points of the interventricular septum for segmental positioning and voxel point calibration (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eSubsequently, the end-diastolic epicardium and epicardium of both four-chamber and two-chamber heart views were delineated, with the positioning line extending from the mitral orifice to the apex. The global and regional myocardial strain parameters of the left ventricle were then assessed, encompassing the radial, circumferential, and longitudinal peak strains at the base, mid, and apical segments of the left ventricle(Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). In this analysis, the end-diastolic myocardial voxel position serves as the reference point, with peak displacement indicating the maximum percentage distance traversed by left ventricular myocardial pixels throughout the cardiac cycle, expressed as a percentage. Ventricular wall thickening is denoted as positive, while myocardial shortening is indicated as negative [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Radial strain is assigned a positive value, whereas circumferential and longitudinal strains are assigned negative values. The presence of delayed enhancement is evaluated by one intermediate and one senior physician. In cases of disagreement, a third senior physician provides confirmation.\u003c/p\u003e\u003cp\u003e\u003cb\u003eStatistics analysis\u003c/b\u003e\u003c/p\u003e\u003cp\u003eSPSS (version 25.0, IBM SPSS Inc., Chicago, IL, USA) and R Studio (version Version 1.3.959) were used for analysis. Kolmogorov – Smirnov test was used to test whether the parameters were normal distribution.The data are expressed as mean and standard deviation (SD) or median and interquartile range (IQR, 25% – 75%). Levene's test was used to test the homogeneity of variance. T test was used when the parameters of DMD patients and volunteers conformed to the normal distribution and the variance was homogeneous. If not, the non-parametric test was used. P \u0026lt; 0.05 showed that the difference was statistically significant.\u003c/p\u003e"},{"header":"Result","content":"\u003cp\u003e\u003cb\u003eBaseline data and cardiac function\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAccording to the inclusion and exclusion criteria, 99 DMD patients (8 ± 2 years old) and 61 healthy volunteers (8 ± 3years old)were included (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). There was no significant difference in age and body mass index between DMD patients and normal control group, but the heart rate of DMD patients was significantly higher than that of normal control group. Among 99 patients with DMD, 84 (84.8%) belonged to DMD gene fragment deletion, 11 (11.1%) belonged to DMD gene repeat mutation, and 4 (4.1%) belonged to DMD gene point mutation. Among them, 7 patients lost walking ability completely. All patients were treated with glucocorticoids. In terms of cardiac function, the LVEF, the global radial (37.05 ± 10.14 vs 40.37 ± 8.52), circumferential (-20.30 ± 5.85 vs -21.37 ± 3.56) and longitudinal (− 13.57 ± 2.81 vs-14.86 ± 2.34) strain of the left ventricle decreased significantly (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). According to segmental analysis of left ventricular strain, we found that radial (46.93 ± 13.47 vs 55.43 ± 13.13) and circumferential (− 16.18 ± 3.15 vs-18.08 ± 1.96) strain at the base of the left ventricle decreased significantly. The radial (35.37 ± 11.36 vs 40.23 ± 10.93), circumferential (− 20.48 ± 3.89 vs-22.08 ± 2.83) and longitudinal (− 12.39 ± 3.38 vs-14.09 ± 2.83) strain at the middle all decreased significantly. The circumferential (− 12.39 ± 3.38 vs-14.09 ± 2.83) strain (-23.70 ± 5.85 vs -25.37 ± 3.65) and longitudinal (− 16.61 ± 2.46 vs-17.97 ± 2.05) strain at the apex decreased significantly (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBaseline characteristics and CMR parameters of study population\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHealthy group (N = 61)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDMD group (N = 99)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8 ± 3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8 ± 2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody mass index(kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e17.92 ± 5.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17.77 ± 3.83\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeart rate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e86 ± 14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e98 ± 16*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGenetics\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMutation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRepetition\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDeletion\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e84\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMyocardial enzyme\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCreatine kinase increased\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCreatine kinase isoenzyme increased\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMyoglobin increased\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCardiac troponin increased\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e25\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWheelchair\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlucocorticoids\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV function\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV ejection fraction(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e62.74 ± 4.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e58.73 ± 7.00*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV end-diastolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e75.03 ± 12.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e73.27 ± 13.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV end-systolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e29.81 ± 10.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e29.86 ± 13.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV stroke volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50.05 ± 17.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e43.29 ± 13.93*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV mass index (g/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.56 ± 0.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.54 ± 0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV function\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV ejection fraction(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e54.11 ± 6.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e51.93 ± 10.35\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV end-diastolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e73.37 ± 15.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e62.32 ± 13.74*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV end-systolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.62 ± 8.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30.61 ± 7.72*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eGlobal Strain\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e40.37 ± 8.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e37.05 ± 10.14*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-21.37 ± 3.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-20.30 ± 5.85*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-14.86 ± 2.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-13.57 ± 2.81*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSegment strain\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55.43 ± 13.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e46.93 ± 13.47*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-18.08 ± 1.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-16.18 ± 3.15*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-11.38 ± 4.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-12.14 ± 4.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e40.23 ± 10.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e35.37 ± 11.36*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-22.08 ± 2.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-20.48 ± 3.89*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-14.09 ± 2.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-12.39 ± 3.38*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32.66 ± 10.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e34.72 ± 16.77\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-25.37 ± 3.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-23.70 ± 5.85*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-17.97 ± 2.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-16.61 ± 2.46*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"3\"\u003eCMR: cardiac magnetic resonance, DMD:duchenne muscular dystrophy, *:P \u0026lt; 0.05.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eComparison of left ventricular function, global and local myocardial strain at different age\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAs shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, there was no significant difference in age, body mass index, LVEF, left ventricular end-diastolic volume index, left ventricular mass index, left ventricular global and local strain between 3-6-year-old DMD patients (n = 15) and normal volunteers (n = 21). Though there was no significant difference in age, BMI, left ventricular end-diastolic volume index, and left ventricular mass index between DMD patients (n = 63) and normal volunteers (n = 18) at the age of 7–10 years, LVEF (59.58 ± 7.09 vs 63.39 ± 5.27), left ventricular global radial (37.34 ± 9.78 vs 42.95 ± 9.22), circumferential (− 20.75 ± 3.77 vs -22.09 ± 2.46) and longitudinal (− 13.91 ± 2.81 vs -15.69 ± 2.52) strain was also lower than that of normal volunteers. Analyzing the local strain changes (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e), we found that the radial (47.82 ± 13.63 vs 60.08 ± 48.37) and circumferential strain (− 16.03 ± 2.78 vs -18.31 ± 1.37) of left ventricular basal segment, radial (36.24 ± 11.24 vs 43.40 ± 11.63), circumferential (− 20.75 ± 3.37 vs -22.65 ± 3.01) and longitudinal strain (− 12.48 ± 3.32 vs -15.41 ± 2.77) of left ventricular middle were significantly lower than those of normal control group. There was no decrease in three directions of apical segment. With the increase of age, compared with normal volunteers, patients with DMD at the age of 11–14 years old further expanded the range of local strain reduction in the left ventricle than those in the age group of 7–10 years, except for the reduction of LVEF (59.61 ± 9.27 vs 62.22 ± 3.93), left ventricular global radial (36.48 ± 10.22 vs 41.82 ± 8.38), circumferential (− 19.49 ± 4.13 vs -21.97 ± 2.37) and longitudinal (− 12.59 ± 2.38 vs -14.51 ± 2.16) were all decreased. Among the segments, the radial (43.84 ± 10.71 vs 55.64 ± 12.17) and circumferential (− 16.61 ± 3.17 vs -18.55 ± 1.41) strain at the left ventricular basal segment, the radial (32.46 ± 12.71 vs 42.43 ± 11.13) and circumferential (− 19.46 ± 4.51 vs -22.45 ± 2.34) strain at the middle segment, circumferential (− 22.80 ± 5.99 vs -25.99 ± 3.19) and longitudinal (− 15.54 ± 1.95 vs -17.98 ± 1.66) strain at the apical segment were all significantly reduced.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of CMR parameters between different age DMD groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e3–6 year\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003e7–10 year\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003e11–14 year\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHealthy group\u003c/p\u003e\u003cp\u003e(N = 21)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDMD group\u003c/p\u003e\u003cp\u003e(N = 15)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHealthy group\u003c/p\u003e\u003cp\u003e(N = 18)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eDMD group\u003c/p\u003e\u003cp\u003e(N = 63)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eHealthy group\u003c/p\u003e\u003cp\u003e(N = 22)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eDMD group\u003c/p\u003e\u003cp\u003e(N = 21)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 ± 2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6 ± 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e8 ± 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e8 ± 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e12 ± 2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e12 ± 1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody mass index(kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e16.45 ± 4.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16.29 ± 1.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e18.66 ± 7.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e17.13 ± 3.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e18.71 ± 1.95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e21.34 ± 4.80\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV function\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV ejection fraction(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e62.72 ± 4.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e59.60 ± 5.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e63.39 ± 5.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e59.58 ± 7.09*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e62.22 ± 3.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e59.61 ± 9.27*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV end-diastolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e73.37 ± 12.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e71.65 ± 10.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e71.49 ± 11.90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e73.21 ± 14.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e79.51 ± 12.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e74.59 ± 11.88\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV end-systolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e28.24 ± 5.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e29.48 ± 4.68\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e25.73 ± 5.68\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e30.37 ± 8.84\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e30.02 ± 5.95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e32.23 ± 10.81\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV stroke volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e33.91 ± 9.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e35.17 ± 7.44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e49.17 ± 4.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e44.09 ± 13.90*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e66.18 ± 12.40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e52.70 ± 12.89*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV mass index (g/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.06 ± 0.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.98 ± 0.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.55 ± 0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.55 ± 0.89\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.60 ± 0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.59 ± 0.15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeart rate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e92 ± 13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e98 ± 10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e88 ± 15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e99 ± 17*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e80 ± 13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e93 ± 16*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV function\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV ejection fraction(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e53.03 ± 4.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e49.28 ± 9.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e56.15 ± 6.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e52.95 ± 11.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e53.48 ± 6.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e50.78 ± 6.12\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV end-diastolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e67.67 ± 13.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e60.26 ± 12.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e70.77 ± 14.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e63.85 ± 13.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e80.93 ± 15.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e59.16 ± 15.44*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV end-systolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e33.45 ± 8.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31.06 ± 10.23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e33.06 ± 6.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e30.62 ± 7.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e38.74 ± 9.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e30.23 ± 6.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eGlobal Strain\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e36.63 ± 6.98\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e36.58 ± 9.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e42.95 ± 9.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e37.34 ± 9.78*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e41.82 ± 8.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e36.48 ± 10.22*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-20.87 ± 2.70\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-20.28 ± 3.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-22.09 ± 2.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-20.75 ± 3.77*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-21.97 ± 2.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-19.49 ± 4.13*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-14.55 ± 2.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-13.50 ± 3.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-15.69 ± 2.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-13.91 ± 2.81*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-14.51 ± 2.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-12.59 ± 2.38*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSegment strain\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e51.21 ± 10.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e47.50 ± 16.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e60.08 ± 48.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e47.82 ± 13.63*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e55.64 ± 12.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e43.84 ± 10.71*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-17.39 ± 2.66\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-16.19 ± 4.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-18.31 ± 1.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-16.03 ± 2.78*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-18.55 ± 1.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-16.61 ± 3.17*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-12.14 ± 3.94\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-10.55 ± 5.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-15.69 ± 2.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-12.00 ± 4.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-11.47 ± 4.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-10.11 ± 3.14\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e35.24 ± 8.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e35.74 ± 9.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e43.40 ± 11.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e36.24 ± 11.24*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e42.43 ± 11.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e32.46 ± 12.71*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-21.19 ± 3.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-20.72 ± 3.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-22.65 ± 3.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-20.75 ± 3.37*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-22.45 ± 2.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-19.46 ± 4.51*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-13.62 ± 2.60\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-12.68 ± 3.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-15.41 ± 2.77\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-12.48 ± 3.32*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-13.45 ± 2.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-11.89 ± 3.20\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e30.04 ± 9.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31.78 ± 11.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e32.92 ± 9.97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e33.66 ± 15.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e34.93 ± 11.98\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e40.02 ± 22.61\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-24.78 ± 3.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-24.22 ± 4.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-25.30 ± 4.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-23.90 ± 6.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-25.99 ± 3.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-22.80 ± 5.99*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-17.62 ± 1.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-16.51 ± 2.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-18.36 ± 2.77\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-16.98 ± 2.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-17.98 ± 1.66\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-15.54 ± 1.95*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eCMR: cardiac magnetic resonance, DMD:duchenne muscular dystrophy, *:Compared to healthy group of the same age group P \u0026lt; 0.05.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eComparison of global and local myocardial strain in control group, LVEF preserved group and LVEF reduced group\u003c/b\u003e\u003c/p\u003e\u003cp\u003eOf the 99 patients, 22 (22%) had decreased LVEF, and 77(78%) had preserved LVEF. Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the comparison of left ventricular global and local myocardial strain among normal control group (mean age 8 ± 3 years), DMD patients in LVEF preserved group (mean age 8 ± 2 years) and DMD patients in LVEF declined group (mean age 9 ± 2 years). For patients in LVEF preserved group, even if there was no significant difference in cardiac function between LVEF preserved group and normal control group (61.37 ± 6.06 vs 62.74 ± 4.48), the global and local myocardial strain of left ventricle had decreased in different degree. The global longitudinal strain of left ventricle (− 13.74 ± 2.83 vs -14.86 ± 2.34) decreased significantly compared with the normal control group. For the left ventricular segments, radial (49.42 ± 13.67 vs 55.43 ± 13.13) and circumferential (− 16.50 ± 3.23 vs -18.08 ± 1.96) strain of left ventricular basal segment, longitudinal strain in the middle (− 12.41 ± 3.46 vs -14.09 ± 2.83) and apical (− 16.96 ± 2.37 vs -17.97 ± 2.05) segments decreased significantly in the LVEF preserved group. For patients with decreased LVEF, the global and local strain of left ventricle were further reduced than those with preserved LVEF. The global strain in three directions in the LVEF decreased group was significantly lower than that in the normal control group. Furthermore, the global radial strain in the LVEF decreased group was significantly lower than that in the preserved LVEF group. In segmental analysis, it was found that the radial (38.20 ± 8.29 vs 49.42 ± 13.67) and circumferential (− 15.06 ± 2.62 vs -16.50 ± 3.23) strain of basal segments, longitudinal strain of apical segment(− 16.36 ± 2.46 vs -16.96 ± 2.37) in LVEF decreased group were further lower than those in LVEF preserved group.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of CMR parameters between healthy, LVEF ≥ 55% DMD group and LVEF \u0026lt; 55% DMD group\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHealthy group\u003c/p\u003e\u003cp\u003e(N = 61)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLVEF ≥ 55% DMD group (N = 77)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLVEF \u0026lt; 55% DMD group (N = 22)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8 ± 3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8 ± 2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e9 ± 2*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody mass index(kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e17.92 ± 5.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17.82 ± 3.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e17.62 ± 3.95\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV function\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV ejection fraction(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e62.74 ± 4.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e61.37 ± 6.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e53.34 ± 7.84*#\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV end-diastolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e75.03 ± 12.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e71.82 ± 12.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e78.34 ± 15.13\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV end-systolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e29.81 ± 10.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e26.73 ± 7.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e40.80 ± 20.25*#\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV stroke volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50.05 ± 17.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e42.84 ± 13.49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e44.91 ± 15.60\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV mass index (g/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.56 ± 0.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.58 ± 0.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.53 ± 0.14\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeart Rate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e86 ± 14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e98 ± 17*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e96 ± 16*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV function\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV ejection fraction(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e54.11 ± 6.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e53.49 ± 10.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e46.49 ± 9.45*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV end-diastolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e73.37 ± 15.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e63.11 ± 13.40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e59.51 ± 14.88*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV end-systolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.62 ± 8.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e29.76 ± 7.22*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e33.57 ± 8.83\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eGlobal Strain\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e40.37 ± 8.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e39.01 ± 9.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e30.20 ± 9.00*#\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-25.37 ± 3.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-20.76 ± 3.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-17.83 ± 3.74*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-14.86 ± 2.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-13.74 ± 2.83*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-12.97 ± 2.75*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSegment strain\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55.43 ± 13.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e49.42 ± 13.67*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e38.20 ± 8.29*#\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-18.08 ± 1.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-16.50 ± 3.23*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-15.06 ± 2.62*#\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-11.38 ± 4.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-11.44 ± 4.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-11.16 ± 3.97\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e40.23 ± 10.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e37.72 ± 10.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e27.15 ± 9.29*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-22.08 ± 2.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-21.19 ± 3.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-17.97 ± 4.47*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-14.09 ± 2.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-12.41 ± 3.46*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-12.32 ± 3.14*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32.66 ± 10.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e35.47 ± 15.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e32.13 ± 21.18\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-25.37 ± 3.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-24.77 ± 4.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-19.95 ± 8.64*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-17.97 ± 2.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-16.96 ± 2.37*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-16.36 ± 2.46*#\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eCMR: cardiac magnetic resonance, DMD:duchenne muscular dystrophy, *:Compared to healthy volunteers P \u0026lt; 0.05, #: Compared to patients with LVEF ≥ 55.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eThe difference in myocardial strain between LGE positive and LGE negative DMD patients\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAs shown in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, 51 (52%) of 99 patients were found to be LGE positive by magnetic resonance delayed enhancement image. The average age of LGE positive patients was 9 ± 2 years old and that of LGE negative patients was 7 ± 2 years old. LGE positive patients were older than LGE negative patients (p \u0026lt; 0.05). The comparative study found that there was no significant difference in age between LGE negative patients and normal volunteers. LGE negative patients showed a decrease in global and local myocardial strain than normal group without a decrease in cardiac function (60.89 ± 6.42 vs 62.74 ± 4.48). The global longitudinal strain (− 13.64 ± 3.01 vs -14.86 ± 2.34), radial (48.52 ± 13.05 vs -55.43 ± 13.13) and circumferential (− 16.24 ± 3.42 vs -18.08 ± 1.96) strain of left ventricular basal segment, longitudinal strain of middle (− 12.43 ± 3.54 vs -14.09 ± 2.83) and apical (− 16.62 ± 2.57 vs -17.97 ± 2.05) segments were significantly lower than those of normal volunteers. Meanwhile, the LVEF of LGE positive patients was significantly lower than that of normal volunteers (58.19 ± 7.92 vs 60.89 ± 6.42) or LGE negative patients (58.19 ± 7.92 vs 62.74 ± 4.48). In terms of myocardial strain, LGE positive patients had more segments with reduced myocardial strain compared with controls. However, there was no significant difference in global and segments strain between LGE negative and LGE positive patients.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of CMR parameters between healthy, LGE negative DMD and LGE positive DMD group\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHealthy group\u003c/p\u003e\u003cp\u003e(N = 61)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLGE negative\u003c/p\u003e\u003cp\u003eDMD group (N = 51)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLGE positive\u003c/p\u003e\u003cp\u003eDMD group(N = 48)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8 ± 3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7 ± 2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e9 ± 2*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody mass index(kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e17.92 ± 5.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16.46 ± 2.66\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e19.15 ± 4.38#\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV function\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV ejection fraction(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e62.74 ± 4.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e60.89 ± 6.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e58.19 ± 7.92*#\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV end-diastolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e75.03 ± 12.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e72.19 ± 11.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e74.42 ± 14.63\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV end-systolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e29.81 ± 10.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e29.77 ± 6.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e26.93 ± 5.77\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV stroke volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50.05 ± 17.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e41.47 ± 15.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e45.24 ± 12.05\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLV mass index (g/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.56 ± 0.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.53 ± 0.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.57 ± 0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeart Rate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e86 ± 14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e96 ± 15*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e99 ± 18*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV function\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV ejection fraction(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e54.11 ± 6.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e53.07 ± 12.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e50.72 ± 8.21\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV end-diastolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e73.37 ± 15.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e62.74 ± 13.24*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e61.86 ± 14.37*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRV end-systolic volume index (ml/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.62 ± 8.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30.48 ± 8.76*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e30.75 ± 6.54*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eGlobal Strain\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e40.37 ± 8.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e37.23 ± 10.43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e36.86 ± 9.93\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-25.37 ± 3.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-20.33 ± 3.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-19.88 ± 3.75*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobal longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-14.86 ± 2.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-13.64 ± 3.01*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-13.49 ± 2.62*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSegment strain\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55.43 ± 13.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e48.52 ± 13.05*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e45.24 ± 13.85*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-18.08 ± 1.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-16.24 ± 3.42*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-16.13 ± 2.88*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-11.38 ± 4.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-11.42 ± 4.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-11.34 ± 3.93\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e40.23 ± 10.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e36.17 ± 11.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e34.52 ± 11.56*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-22.08 ± 2.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-20.81 ± 3.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-20.18 ± 4.36*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMiddle longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-14.09 ± 2.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-12.43 ± 3.54*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-12.34 ± 3.23*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical radial peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32.66 ± 10.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e32.65 ± 16.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e36.93 ± 17.30\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical circumferential peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-25.37 ± 3.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-24.16 ± 4.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-23.22 ± 7.35\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApical longitudinal peak strain(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-17.97 ± 2.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-16.62 ± 2.57*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-16.59 ± 2.37*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eCMR: cardiac magnetic resonance, DMD:duchenne muscular dystrophy, LGE:late gadolinium enhancement, *:Compared to healthy volunteers P \u0026lt; 0.05, #: Compared to patients with negative LGE.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn patients with DMD, gene mutations result in reduced synthesis of myotrophin, decreased stability of the dystrophin glycoprotein complex junction structure, increased fragility of cardiomyocyte myomembranes, significantly elevated intracellular calcium levels, damage to the myofiber membrane, and degeneration of myofibers [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e], ultimately leading to myocardial systolic dysfunction. Our findings regarding myocardial systolic dysfunction are as follows: 1) In DMD children aged 1\u0026ndash;6 years, there is no observed decrease in myocardial strain. However, in patients aged 7\u0026ndash;10 years and 11\u0026ndash;14 years, both global and regional myocardial strain of the left ventricle exhibit varying degrees of reduction, with a progression from the basal epicardium to the apical and endocardium. 2) We also conducted an analysis of the overall and regional myocardial strain in patients with both preserved and decreased LVEF. The results showed that the overall and local myocardial strain in patients with preserved LVEF was significantly lower than that in normal control group. 3) Among patients who are negative for LGE, there is no significant difference in LVEF compared to the control group. Nevertheless, the radial and circumferential strains at the base of the left ventricle, as well as the global longitudinal strain at the middle and apex, are significantly lower than those in normal controls.\u003c/p\u003e\u003cp\u003eResearch has demonstrated that as the disease progresses, extensive myocardial cell necrosis occurs, along with myocardial fat infiltration and fibrosis replacement, which contribute to cardiac remodeling and dysfunction [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. This progression often culminates in late-stage heart failure, accompanied by life-threatening arrhythmias, ultimately resulting in cardiac death [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The U.S. working group on nursing care for Duchenne muscular dystrophy has explicitly recommended proactive treatment for patients exhibiting reduced cardiac function or myocardial fibrosis. The guidelines further emphasize that interventions initiated only after clear evidence of myocardial injury are insufficient [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Consequently, there is a pressing need for effective methods to detect myocardial injury early in pediatric patients. As early as 2005, researchers employed 1.5T magnetic resonance tagging technology to conduct cardiac imaging in a cohort of 13 patients with Duchenne muscular dystrophy, with an average age of 10.6\u0026thinsp;\u0026plusmn;\u0026thinsp;3.01 years.\u003c/p\u003e\u003cp\u003eThe study revealed that, although the left ventricular volume and ejection fraction in patients with DMD were within normal ranges compared to the control group, there was a significant reduction in the overall circumferential strain of the ventricular base and middle layer [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Batra et al. also demonstrated a decline in circumferential strain in dystrophic myocardium, underscoring the importance of early and longitudinal cardiac function assessments in DMD to identify early biomarkers of cardiac dysfunction, which could inform the design of clinical trials aimed at mitigating cardiac pathology [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Consequently, it has been recognized that myocardial damage occurs much earlier than previously detected. However, the precise onset time in patients remains unclear. Building on the aforementioned research, we expanded the sample size and conducted a stratified analysis based on different age groups of children. Our findings indicated that children aged 3\u0026ndash;6 years did not exhibit significant cardiac dysfunction. In contrast, children aged 7\u0026ndash;10 years and 11\u0026ndash;14 years showed varying degrees of reduction in overall and regional left ventricular strain. This discovery could enhance clinicians' ability to diagnose myocardial damage in DMD patients over the age of 7 years.This study significantly contributes to enhancing the diagnostic acumen of clinicians regarding myocardial damage in DMD patients over the age of seven. It offers a nuanced understanding of myocardial damage across various pediatric age groups and is anticipated to inform future expert consensus guidelines.\u003c/p\u003e\u003cp\u003eThe findings indicate that myocardial dysfunction in the basal region of the left ventricle among children aged 7\u0026ndash;10 years is predominantly characterized by impaired radial and circumferential motion, suggesting subepicardial and intermediate myocardial injury in this region. This observation aligns with the myocardial fibrosis patterns identified through LGE imaging [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. In patients aged 11\u0026ndash;14, there is a noted decline in myocardial strain in both the basal and middle regions, accompanied by a reduction in longitudinal strain at the apex. This suggests a progression of myocardial dysfunction from the basal epicardium towards the apical and endocardial regions. Consistent with the findings of Lang et al [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], who reported severe cardiac dysfunction (LVEF\u0026thinsp;\u0026lt;\u0026thinsp;55%) in approximately 18% of DMD patients, our study found that 22 out of 99 patients (22%) exhibited an LVEF below 55%. However, even among patients without overt cardiac dysfunction, myocardial strain abnormalities were evident.\u003c/p\u003e\u003cp\u003eHor et al. and Liu et al. have demonstrated that myocardial strain in patients with DMD who exhibit normal LVEF and negative LGE is significantly reduced compared to a control group [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e][\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. In the present study, we have corroborated this finding through extensive research. These results underscore the limitations of relying solely on traditional indices, such as LVEF\u0026thinsp;\u0026lt;\u0026thinsp;55% and positive LGE, to assess cardiac damage in DMD patients. CMR tissue tracking serves as a valuable adjunct to LVEF and LGE, facilitating the quantitative assessment of cardiac dysfunction and providing a robust foundation for early clinical intervention. However, this study has certain limitations. Firstly, the duration of the study was relatively short, and there was no long-term follow-up of the participants. Secondly, as a single-center study, the findings may not be entirely representative of data from other centers, although it is acknowledged that DMD is a rare condition. Nonetheless, the study's large sample size offers a significant advantage over many other studies, partially mitigating this limitation.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn patients with DMD, myocardial dysfunction predominantly manifests in children older than seven years, demonstrating progression and exacerbation with advancing age. The myocardial injury typically progresses from the basal epicardium towards the apical and endocardial regions. CMR tissue tracking offers an early assessment of cardiac dysfunction in DMD patients, providing earlier detection compared to conventional measures such as LVEF and LGE.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eConception and design: H.L ,Y. G and L.Gong. Provision of study materials or patients: R. X, H. F.Collection and assembly of data: H.L and H. X.Data analysis and interpretation: H.L, R.X and H.F. Manuscript writing: H. L, Y.G and L. G. All authors contributed to the article and approved the submitted version.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eKamdar F, Garry DJ (2016) Dystrophin-Deficient Cardiomyopathy. J Am Coll Cardiol 67(21):2533\u0026ndash;2546\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBirnkrant DJ, Bushby K, Bann CM, DMD Care Considerations Working Group (2018) Diagnosis and management of Duchenne muscular dystrophy, part 1: diagnosis, and neuromuscular, rehabilitation, endocrine, and gastrointestinal and nutritional management. Lancet Neurol 17:251\u0026ndash;267\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMcNally EM, Kaltman JR, Benson DW et al (2015) Contemporary cardiac issues in Duchenne muscular dystrophy. Working Group of the National Heart, Lung, and Blood Institute in collaboration with Parent Project Muscular Dystrophy. Circulation 131:1590\u0026ndash;1598\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMarkham LW, Kinnett K, Wong BL et al (2008) Corticosteroid treatment retards development of ventricular dysfunction in Duchenne muscular dystrophy. 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Am Heart J 157(1):1021\u0026ndash;1025\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXu HY, Chen J, Yang ZG et al (2017) Early marker of regional left ventricular deformation in patients with hypertrophic cardiomyopathy evaluated by MRI tissue tracking: The effects of myocardial hypertrophy and fibrosis. J Magn Reson Imaging 46(5):1368\u0026ndash;1376\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBuss SJ, Breuninger K, Lehrke S et al (2015) Assessment of myocardial deformation with cardiac magnetic resonance strain imaging improves risk stratification in patients with dilated cardiomyopathy. Eur Heart J Cardiovasc Imaging 16(3):307\u0026ndash;315\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDorbala S, Vangala D, Bruyere J et al (2014) Coronary microvascular dysfunction is related to abnormalities in myocardial structure and function in cardiac amyloidosis. JACC Heart Fail 2(4):358\u0026ndash;367\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHeermann P, Hedderich DM, Paul M et al (2014) Biventricular myocardial strain analysis in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) using cardiovascular magnetic resonance feature tracking. J Cardiovasc Magn Reson 16(1):75\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAzzu A, Antonopoulos AS, Krupickova S et al (2023) Myocardial strain analysis by cardiac magnetic resonance 3D feature-tracking identifies subclinical abnormalities in patients with neuromuscular disease and no overt cardiac involvement. Eur Heart J Cardiovasc Imaging 24(4):503\u0026ndash;511\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSiegel B, Olivieri L, Gordish-Dressman H et al (2018) Myocardial Strain Using Cardiac MR Feature Tracking and Speckle Tracking Echocardiography in Duchenne Muscular Dystrophy Patients. Pediatr Cardiol 39(3):478\u0026ndash;483\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBushby K, Finkel R, Birnkrant DJ et al (2010) Diagnosis and management of Duchenne muscular dystrophy, part 1: diagnosis, and pharmacological and psychosocial management. Lancet Neurol 9(1):77\u0026ndash;93\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAmaki M, Savino J, Ain DL et al (2014) Diagnostic concordance of echocardiography and cardiac magnetic resonance-based tissue tracking for differentiating constrictive pericarditis from restrictive cardiomyopathy. Circ Cardiovasc Imaging 7(5):819\u0026ndash;827\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDeconinck N, Dan B (2007) Pathophysiology of duchenne muscular dystrophy: current hypotheses. 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Cardiol Young :1\u0026ndash;6\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDuboc D, Meune C, Lerebours G et al (2005) Effect of perindopril on the onset and progression of left ventricular dysfunction in Duchenne muscular dystrophy. J Am Coll Cardiol 45:855\u0026ndash;857\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAshford MW, Liu W, Lin SJ et al (2005) Occult cardiac contractile dysfunction in dystrophin-deficient children revealed by cardiac magnetic resonance strain imaging. Circulation 112(16):2462\u0026ndash;2467 (25)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBatra A, Barnard et al (2022) Longitudinal changes in cardiac function in Duchenne muscular dystrophy population as measured by magnetic resonance imaging. BMC Cardiovasc Disord 22(1):260. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s12872-022-02688-5\u003c/span\u003e\u003cspan address=\"10.1186/s12872-022-02688-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXu R, Xu H, Liu H et al (2020) The prevalence and natural progress of myocardial fibrosis in Duchenne muscular dystrophy patients. Eur Heart J 41(Supple2). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/ehjci/ehaa946.0214\u003c/span\u003e\u003cspan address=\"10.1093/ehjci/ehaa946.0214\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLang SM, Shugh S, Mazur W (2015) Myocardial Fibrosis and Left Ventricular Dysfunction in Duchenne Muscular Dystrophy Carriers Using Cardiac Magnetic Resonance Imaging. Pediatr Cardiol 36(7):1495\u0026ndash;1501\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHor KN, Wansapura J, Markham LW et al (2009) Circumferential strain analysis identifies strata of cardiomyopathy in Duchenne muscular dystrophy: a cardiac magnetic resonance tagging study. J Am Coll Cardiol 53(14):1204\u0026ndash;1210\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu Z-Q, Maforo, Nyasha G et al (2024) MRI-Based Circumferential Strain in Boys with Early Duchenne Muscular Dystrophy Cardiomyopathy. Diagnostics 14(23). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/diagnostics14232673\u003c/span\u003e\u003cspan address=\"10.3390/diagnostics14232673\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Duchenne Muscular Dystrophy, Magnetic Resonance Imaging, Tissue tracking","lastPublishedDoi":"10.21203/rs.3.rs-7231467/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7231467/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackgro\u003c/strong\u003eund: Duchenne muscular dystrophy (DMD) is a progressive disorder affecting skeletal muscles, the heart, the respiratory system, and the nervous system, with cardiovascular complications emerging as the primary cause of mortality in DMD patients.\u003c/p\u003e\n\u003cp\u003eObjectives: This study aims to quantitatively assess myocardial strain in patients with DMD using cardiac magnetic resonance (CMR) tissue tracking technology. The study seeks to evaluate subclinical cardiac dysfunction and investigate variations in myocardial dysfunction across different age groups. Additionally, it aims to explore the correlation between myocardial strain parameters and myocardial fibrosis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: Between August 2018 and January 2020, 110 DMD patients diagnosed at a pediatric neurology outpatient department were included in the study. The patients were categorized into three age groups: 1-6 years, 7-10 years, and 11-14 years. Based on left ventricular ejection fraction (LVEF), the patients were further divided into a normal LVEF group (LVEF ≥ 55%) and a decreased LVEF group (LVEF \u0026lt; 55%). Furthermore, based on the presence of delayed enhancement, patients were classified into late gadolinium enhancement (LGE) positive and LGE negative groups. Additionally, 69 healthy volunteers were recruited for comparison. In conclusion, parameters of left ventricular (LV) function, along with global and local myocardial strain parameters of the left ventricle, were assessed. These included radial, circumferential, and longitudinal peak strains at the base, middle, and apex of the left ventricle. Statistical analyses were conducted using the T-test.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e In comparison to the control group (n = 21), the cardiac function and myocardial strain of patients aged 3-6 years (n = 15) did not exhibit any decline. LVEF (59.58 ± 7.09 vs 63.39 ± 5.27), left ventricular global radial (37.34 ± 9.78 vs 42.95 ± 9.22), circumferential (- 20.75 ± 3.77 vs -22.09 ± 2.46) and longitudinal (- 13.91 ± 2.81 vs -15.69 ± 2.52) strain and local strain parameters of DMD patients (n = 63) at the age of 7-10 years were lower than that of normal volunteers(n = 18) . With the increase of age, compared with normal volunteers(n = 22), patients with DMD at the age of 11-14 years old(n = 21) further expanded the range of local strain reduction in the left ventricle than those in the age group of 7-10 years, except for the reduction of LVEF (59.61 ± 9.27 vs 62.22 ± 3.93), left ventricular global radial (36.48 ± 10.22 vs 41.82 ± 8.38), circumferential (- 19.49 ± 4.13 vs -21.97 ± 2.37) and longitudinal (- 12.59 ± 2.38 vs -14.51 ± 2.16) were all decreased. The number of the decreased local strain parameters were more than 7-10 years patients. For patients in LVEF preserved group(n = 77), even if there was no significant difference in cardiac function between LVEF preserved group and normal control group (61.37 ± 6.06 vs 62.74 ± 4.48), the global and local myocardial strain of left ventricle had decreased in different degree. LGE negative patients (n = 51)showed a decrease in global and local myocardial strain without a decrease in cardiac function (60.89 ± 6.42 vs 62.74 ± 4.48).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn patients with DMD, myocardial dysfunction predominantly manifests in children older than seven years, exhibiting a subtle progression that exacerbates with advancing age. The myocardial injury tends to develop from the basal epicardium towards the apical and endocardial regions. CMR tissue tracking offers an earlier assessment of cardiac dysfunction in DMD patients compared to traditional parameters such as LVEF and LGE.\u003c/p\u003e","manuscriptTitle":"The Correlation Between Myocardial Dysfunction and Age in Duchenne Muscular Dystrophy: Assessed by Cardiac Magnetic Resonance Tissue Tracking","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-06 08:19:36","doi":"10.21203/rs.3.rs-7231467/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a22672fe-78a9-4142-961d-b80bfc25fa1d","owner":[],"postedDate":"August 6th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-11T04:23:31+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-06 08:19:36","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7231467","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7231467","identity":"rs-7231467","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}