Maragiannis Dimitrios, Alvarez Paulino A, Ghosn Mohamad G, Chin Karen, Hinojosa Jeremy J, Buergler John M, Shah Dipan J, Nagueh Sherif F
Cardiovascular Imaging Section, 401 General Army Hospital of Athens, Athens, Greece.
Methodist DeBakey Heart and Vascular Center, and Cardiovascular Imaging Institute, The Methodist Hospital, 6550 Fannin, SM-677, Houston, TX, 77030, USA.
Int J Cardiovasc Imaging. 2018 Jan;34(1):121-129. doi: 10.1007/s10554-017-1214-z. Epub 2017 Jul 26.
We sought to determine the relation between myocardial extracellular volume (ECV), left ventricular (LV) diastolic function, and exercise tolerance in patients with hypertrophic cardiomyopathy (HCM). Forty five HCM patients with an ejection fraction >50% and no previous septal reduction therapy underwent imaging by CMR and transthoracic echocardiography. CMR was used to quantify LV volumes, mass, EF, LA volumes, scar burden, pre and post contrast T1 relaxation times and ECV. Echocardiography was used to measure outflow tract gradients, mitral inflow and annular velocities, circumferential strain, systolic, early and late diastolic strain rates. Exercise duration and peak oxygen consumption were noted. HCM patients had increased native T1 relaxation time and ECV vs. controls [ECV controls: 24.7 (23.2-26.4) vs. HCM: 26.8 (24.6-31.3)%, P = 0.014]. Both parameters were significantly associated with LV diastolic dysfunction, circumferential strain, diastolic strain rate and peak oxygen consumption (r = -0.73, P < 0.001). Compared to controls, HCM patients have significantly longer native T1 relaxation time and higher ECV. These structural changes lead to worse LV global and segmental diastolic function and in turn reduced exercise tolerance.
我们试图确定肥厚型心肌病（HCM）患者的心肌细胞外容积（ECV）、左心室（LV）舒张功能和运动耐量之间的关系。45例射血分数>50%且既往未接受过室间隔减容治疗的HCM患者接受了心脏磁共振成像（CMR）和经胸超声心动图检查。CMR用于量化左心室容积、质量、射血分数、左心房容积、瘢痕负荷、对比剂注射前后的T1弛豫时间和ECV。超声心动图用于测量流出道梯度、二尖瓣流入和环周速度、圆周应变、收缩期、舒张早期和晚期应变率。记录运动持续时间和峰值耗氧量。与对照组相比，HCM患者的固有T1弛豫时间和ECV增加[对照组ECV：24.7（23.2-26.4）% vs. HCM：26.8（24.6-31.3）%，P = 0.014]。这两个参数均与左心室舒张功能障碍、圆周应变、舒张应变率和峰值耗氧量显著相关（r = -0.73，P < 0.001）。与对照组相比，HCM患者的固有T1弛豫时间显著更长，ECV更高。这些结构变化导致左心室整体和节段性舒张功能恶化，进而降低运动耐量。
