定量组织多普勒速度成像对肥厚型心肌病患者左心室局部舒张功能的研究

Detection of left ventricular regional relaxation abnormalities in patients with hypertrophic cardiomyopathy by quantitative tissue velocity imaging

目的 应用定量组织多普勒速度成像 (QTVI)评价肥厚型心肌病 (HCM )患者左心室局部心肌长轴方向舒张功能。方法 分别获取 1 0例HCM患者和 1 1例正常对照者标准心尖位左心长轴观、二腔观和四腔观图像 ,应用QTVI脱机分析左室中部、基部和二尖瓣环各节段心肌长轴方向在舒张早期 (rVe)和心房收缩期 (rVa)室壁运动速度曲线 ,计算左室中部、基部和二尖瓣环水平的平均rVe、平均rVa及平均rVe/rVa值。脉冲波多普勒测量二尖瓣口舒张早期最大血流流速曲线 (E)和心房收缩期最大血流流速曲线 (A) ,计算E/A值。结果 HCM组左室各节段rVe室壁运动曲线明显低于正常对照组 (P <0 .0 5) ,而左室大部分节段的rVa室壁运动曲线与正常对照组相比差异无显著性意义 (P >0 .0 5)。比较两组E差异具有显著性意义 (P =0 .0 36) ,在两组平均rVe室壁运动曲线的比较中此种差异更为显著 (P <0 .0 0 0 1 )。比较两组A和E/A值差异无显著性意义 (P =0 .2 2 ,P =0 .1 0 1 ) ,而两组各水平平均rVa和平均rVe/rVa值差异具有显著性意义 (P <0 .0 5)。结论 HCM患者局部心肌舒张功能受损。脉冲波多普勒血流信号E、A受前负荷、心肌舒张功能和心房收缩的多重影响 ,而QTVI提取多普勒组织信号成像 。

Objective To assess the left ventricular re gional relaxation abnormalities in patients with hypertrophic cardiomyopathy(HCM) by quantitative tissue velocity imaging(QTVI). Methods Doppler echocardiography and QTVI were performed in HCM (n=10) and healthy subjects (n=11) at apical long-axis, two-chamber and four-chamber view. Regional early diastolic velocity (rVe) and regional atrial contraction (rVa) were measured at each segment of ventricular middle, basal and annular levels. Mean rVe and mean rVa at three levels as well as mean rVe/rVa ratio were calculated. Transmitral inflow peak velocities during early diastole (E) and atrial contraction (A) were also measured and E/A ratio was calculated. Results rVe of all left ventricular segments in HCM were lower than that of healthy subjects ( P<- 0.05-), but compared with healthy subjects majority of rVa in HCM were not different except inferior wall and anterior wall. E between HCM and healthy subjects was different (P= 0.036-), while mean rVe between them was significantly different (P< 0.000 1-). Mean rVa and mean rVe/rVa of three levels were lower in HCM than in healthy subjects (P< 0.05-), but there were no differences of A and E/A between them (P= 0.22-,P= 0.101-). Conclusions Left ventricular regional myocardial relaxation is impaired in HCM. Transmitral inflow E and A are influenced by preload, relaxation of myocardium and atrial contraction, etc, but rVe and rVa reflect myocardial relaxation function independently. QTVI is more sensitive and accurate than conventional Doppler imaging for characterizing regional diastolic properties in HCM.