Ultrasound assessment of left ventricular segmental myocardial transmural displacement characteristics in patients with hypertrophic cardiomyopathy / 中华医学超声杂志（电子版）

ABSTRACT

Objective To evaluate the segmental myocardium of left ventricular wall in patients with myocardial hypertrophic cardiomyopathy (HCM) by TDI-Q, explore whether the segmental myocardium contractile function is changed or not and determine the myocardial mechanics parameters variation. Methods Thirty-two healthy volunteers and twenty-one patients with hypertrophic cardiomyopathy were included and the standard dynamic two-dimensional tissue Doppler imaging (TDI) of mitral, papillary muscle and apical short axis view were collected in three consecutive cardiac cycles. The mechanical parameters variation and characteristics of systolic radial peak displacement (RD) and time to peak in left ventricle subendocardial, mid-myocardium and epicardial myocardium at different level and segment were analyzed.Results In healthy control group, at left ventricular basal, apical and papillary muscle level, there was no significant difference for time to peak and systolic radial peak displacement (F=0.74, 1.28 and 1.79, all P>0.05). In patients with HCM, time to peak of systolic RD at left ventricular different level was asynchronous. Time to peak of RD in septum at papillary muscle levels and apical lateral wall were longer than those of other segments. In healthy control group, except for apical inferior and lateral wall, RD of subendocardial myocardium was significantly greater than that of epicardial myocardium at different segments (t=-1.903, 4.574,-3.552,-2.614,-1.728,-1.790,-1.836,-2.794 and 2.733, all P<0.05 ). In patients with HCM, RD of subendocardial myocardium was significantly greater than that of epicardial myocardium in posterior wall, septum at basal level and in inferior wall, posterior wall and lateral wall at papillary muscle level (t=-2.305,-2.148, 3.550,-1.182 and-3.602, all P < 0.05). At the same segment, transmural RD of subendocardial and subepicardial myocardium in healthy subjects were greater than that in patients with HCM. In inferior wall, posterior wall, lateral wall and septum at basal level, in inferior wall, posterior wall and septum at papillary muscle level, and in lateral wall and septum at apical level, differences of transmural RD were statistically significant (t=-3.787,-2.983,-4.325,-6.972,-2.352, 2.823,-3.274,-1.338 and-2.857, all P<0.05). Conclusions In patients with HCM, synchrony of left ventricular motion at different level was abnormal and transmural RD of endocardial and epicardial myocardium was decreased, which suggested regional systolic dysfunction. Ultrasound assessment of left ventricular segmental transmural mechanics can further reveal left ventricular mechanical characteristics in patients with hypertrophic cardiomyopathy.