Skulstad Helge, Urheim Stig, Edvardsen Thor, Andersen Kai, Lyseggen Erik, Vartdal Trond, Ihlen Halfdan, Smiseth Otto A
Department of Cardiology and the Institute for Surgical Research, Rikshospitalet University Hospital, Oslo, Norway.
J Am Coll Cardiol. 2006 Apr 18;47(8):1672-82. doi: 10.1016/j.jacc.2006.01.051. Epub 2006 Mar 29.
The aim of the study was to compare the ability of the tissue Doppler echocardiographic imaging (TDI) modalities velocity, strain, and displacement to quantify systolic myocardial function.
Several TDI modalities may be used to quantify regional myocardial function, but it is not clear how the different modalities should be applied.
In 10 anesthetized dogs we measured left ventricular pressure, longitudinal myocardial velocity, strain, and displacement by TDI at baseline and during left anterior descending coronary artery (LAD) stenosis and occlusion. Reference methods were segmental shortening by sonomicrometry and segmental work. In 10 patients with acute anterior wall infarction (LAD occlusion) and 15 control subjects, velocity, strain, and displacement measurements were performed.
In the animal study, systolic strain correlated well with segmental shortening (r = 0.96, p < 0.01) and work (r = 0.90, p < 0.01), and differentiated well between non-ischemic (-13.5 +/- 3.2% [mean +/- SD]), moderately ischemic (-6.5 +/- 2.8%), and severely ischemic myocardium (7.1 +/- 13.2%). The ratio post-systolic strain/total strain also differentiated well between levels of ischemia. Displacement and ejection velocity had weaker correlations with segmental shortening (r = 0.92 and r = 0.74, respectively) and regional work (r = 0.85 and r = 0.69), and there was marked overlap between values at baseline and at different levels of ischemia. In the human study, systolic strain differentiated well between infarcted and normal myocardium (1.0 +/- 5.0% vs. -17.8 +/- 3.8%), whereas systolic displacement (-0.3 +/- 1.3 mm vs. -2.3 +/- 0.6 mm) and ejection velocity (0.9 +/- 0.6 cm/s vs. 2.2 +/- 0.6 cm/s) showed overlap. In the infarction group, strain was reduced in segments with infarcted tissue, while systolic velocity and displacement were reduced in all segments and did not reflect the extension of the infarct.
Strain was superior to velocity and displacement for quantification of regional myocardial function. Provided technical limitations can be solved, strain Doppler is the preferred TDI modality for assessing function in ischemic myocardium.
本研究旨在比较组织多普勒超声心动图成像（TDI）的速度、应变和位移模式量化收缩期心肌功能的能力。
几种TDI模式可用于量化局部心肌功能，但尚不清楚应如何应用不同模式。
对10只麻醉犬，在基线以及左前降支冠状动脉（LAD）狭窄和闭塞期间，通过TDI测量左心室压力、心肌纵向速度、应变和位移。参考方法为用超声微测法测量节段缩短率和节段功。对10例急性前壁心肌梗死（LAD闭塞）患者和15名对照者进行速度、应变和位移测量。
在动物研究中，收缩期应变与节段缩短率（r = 0.96，p < 0.01）和功（r = 0.90，p < 0.01）相关性良好，且能很好地区分非缺血心肌（-13.5±3.2%[均值±标准差]）、中度缺血心肌（-6.5±2.8%）和重度缺血心肌（7.1±13.2%）。收缩期末应变/总应变比值在不同缺血水平之间也有良好区分。位移和射血速度与节段缩短率（分别为r = 0.92和r = 0.74）以及局部功（r = 0.85和r = 0.69）的相关性较弱，且基线值与不同缺血水平的值之间存在明显重叠。在人体研究中，收缩期应变在梗死心肌和正常心肌之间有良好区分（1.0±5.0%对-17.8±3.8%），而收缩期位移（-0.3±1.3 mm对-2.3±0.6 mm）和射血速度（0.9±0.6 cm/s对2.2±0.6 cm/s）有重叠。在梗死组中，梗死组织节段的应变降低，而所有节段的收缩期速度和位移均降低，且不能反映梗死范围。
在量化局部心肌功能方面，应变优于速度和位移。如果技术限制能够解决，应变多普勒是评估缺血心肌功能的首选TDI模式。
