Edvardsen Thor, Gerber Bernhard L, Garot Jérôme, Bluemke David A, Lima João A C, Smiseth Otto A
Department of Cardiology, Rikshospitalet University, Oslo, Norway.
Circulation. 2002 Jul 2;106(1):50-6. doi: 10.1161/01.cir.0000019907.77526.75.
Tissue Doppler echocardiography-derived strain rate and strain measurements (SDE) are new quantitative indices of intrinsic cardiac deformation. The aim of this study was to validate and compare these new indices of regional cardiac function to measurements of 3-dimensional myocardial strain by tagged MRI.
The study population included 33 healthy volunteers, 17 patients with acute myocardial infarction, and 8 patients with suspected coronary artery disease who were studied during dobutamine stress echocardiography. Peak systolic myocardial velocities were measured by tissue Doppler echocardiography, peak systolic strain rates and strains by SDE, and strains by tagged MRI. In healthy individuals, longitudinal myocardial Doppler velocities decreased progressively from base to apex, whereas myocardial strain rates and strains were uniform in all segments. In patients with acute infarction, abnormal strains clearly identified dysfunctional areas. In infarcted regions, SDE showed 1.5+/-4.3% longitudinal stretching compared with -15.0+/-3.9% shortening in remote myocardium (P<0.001), and radial measurements showed -6.9+/-4.1% thinning and 14.3+/-5.0% thickening (P<0.001), respectively. During dobutamine infusion, longitudinal strains by SDE increased significantly from -13.5% to -23.8% (P<0.01) and radial strains increased from 13.1+/-3.1% to 29.3+/-11.5% (P<0.01). Comparisons between myocardial strains by SDE and tagged MRI in healthy individuals (n=11), in infarct patients (n=17), and during stress echo (n=4) showed excellent correlations (r=0.89 and r=0.96 for longitudinal and radial strains, respectively, P< 0.001).
The present study demonstrates the ability of Doppler echocardiography to measure myocardial strains in a clinical setting. Myocardial strains by Doppler may represent a new powerful method for quantifying left ventricular function noninvasively in humans.
组织多普勒超声心动图衍生的应变率和应变测量值（SDE）是反映心脏固有变形的新的定量指标。本研究的目的是验证并比较这些新的局部心脏功能指标与标记MRI测量的三维心肌应变。
研究对象包括33名健康志愿者、17名急性心肌梗死患者和8名疑似冠心病患者，他们在多巴酚丁胺负荷超声心动图检查期间接受研究。通过组织多普勒超声心动图测量收缩期心肌峰值速度，通过SDE测量收缩期峰值应变率和应变，通过标记MRI测量应变。在健康个体中，心肌纵向多普勒速度从心底到心尖逐渐降低，而心肌应变率和应变在所有节段均一致。在急性梗死患者中，异常应变可明确识别功能失调区域。在梗死区域，SDE显示纵向伸长率为1.5±4.3%，而远隔心肌缩短率为-15.0±3.9%（P<0.001），径向测量分别显示变薄率为-6.9±4.1%和增厚率为14.3±5.0%（P<0.001）。在多巴酚丁胺输注期间，SDE测量的纵向应变从-13.5%显著增加至-23.8%（P<0.01），径向应变从13.1±3.1%增加至29.3±11.5%（P<0.01）。对健康个体（n=11）、梗死患者（n=17）和负荷超声心动图检查期间（n=4）的SDE测量心肌应变与标记MRI测量心肌应变进行比较，结果显示具有良好的相关性（纵向和径向应变的r分别为0.89和0.96，P<0.001）。
本研究证明了多普勒超声心动图在临床环境中测量心肌应变的能力。多普勒测量的心肌应变可能代表一种在人体中无创定量左心室功能的新的有力方法。
