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.
ABSTRACT
Objective To evaluate left ventricular function in patients with hypertensive hypertrophic cardiomyopathy(HHC)using real-time 3-dimensional echocardiography(RT-3DE).Methods Thirty patients with HHC and 32 control subjects were studied.Full-volume RT-3DE data from apical window were acquired,and regional volumetric time curves of 17 segments were obtained by fast 3-dimensional border detection software.Several left ventricular function parameters were calculated semiautomatically,including global left ventricular end-diastolic volume(EDV),end-systolic volume(ESV),left ventricular ejection fraction(LVEF),the ratio of ESV/EDV of 17 segments,the standard deviation(SD)and difference(Dif)(adjusted by the R-R interval) of time to minimum systolic volume(Tmsv)in 16 segments(Tmsv16-SD and Tmsv16-Dif).Results EDV and ESV were significantly larger in patients with HHC than that in control subjects[(88±29)ml vs (72±15) ml,t=-2.680,P=0.008;(28±10)ml vs (22±6 )ml,t=-2.613,P=0.01].HHC had a higher ratio of ESV/EDV at interventricular septum(IVS)compared with control group[mid-segments of anterior IVS:(40.51±20.28)% vs (26.43±10.10)%,t=-3.378,P=0.002;mid-segments of posterior IVS:(41.44±23.55)% vs (24.46±8.12)%,t=-3.688,P=0.001;apical segments of IVS:(30.96±21.31)% vs (19.53±7.33)%,t=-2.745,P=0.01].In patients with HHC,Tmsv16-SD and Tmsv16-Dif were significantly longer[(2.48±1.38)% vs (1.16±0.26)%,t=-5.117,P＜0.001;(7.67±5.07)% vs (3.95±1.48)%,t=-3.865,P＜0.001].And the prevalence of left ventricular dyssynchrony was higher than that in control subjects(43% vs 3%).Conclusions HHC patients may have regional left ventricular systolic dysfunction before global changes,and have a higher prevalence of left ventricular dyssynchrony.RT-3DE is a useful imaging modality for assessing left ventricular systolic function.