应用超声二维斑点追踪成像技术评价扩张型心肌病患者左室扭转的初步研究

Assessment of left ventricular twist in dilated cardiomyopathy using two-dimensional speckle tracking imaging

目的应用超声二维斑点追踪显像技术(STI)探讨扩张型心肌病患者(DCM)左室扭转(LVtw)运动特征。方法DCM患者33例,年龄匹配的健康志愿者30例。经胸采集3个心动周期标准左室基底部及心尖部短轴二维图像并存贮,运用Echo PAC超声工作站进行脱机分析,获取每个切面的旋转值。左室扭转值定义为左室心尖部旋转值与心底部旋转值的差值。对不同研究对象间心率差异进行时间校标。结果从左室心尖来看,正常人LVtw运动主要表现为心底部顺时针旋转和心尖部逆时针旋转,心脏整体表现为心动周期内逆时针方向为主的扭转运动。DCM患者LVtw运动于收缩期仍维持心底部顺时针旋转、心尖部逆时针旋转及心脏整体收缩期逆时针方向的扭转运动,但其左室扭转峰值[(6.56±2.19)°/(14.44±1.55)°,P<0.001]显著减低。左室峰值扭转与左心功能显著正相关,相关关系密切(Spearman相关系数r=0.762,P=0.00)。结论DCM患者组收缩期左室扭转值减低对于左室收缩功能有很大影响。STI技术为准确地评估左心室扭转运动特征提供了全新的定量工具,具有广阔的临床应用前景。

Objective To assess the value of left ventricular twist （LVtw） in dilated cardiomyopathy （DCM） by 2-dimensional ultrasound speckle-tracking imaging. Methods Basal and apical LV short-axis images were acquired in 33 patients with dilated cardiomyopathy and in 30 healthy volunteers. Using commercially available 2-dimensional strain software, time domain speckle tracking was performed, and regional LV rotation were obtained in each plane. LV twist was defined as apical LV rotation relative to the base. Results As seen from the apex, LV performs a wringing motion with a clockwise rotation at the base and counterclockwise rotation at the apex. LV twist was significantly reduced in DCM （[6.56±2. 19]° vs [14.44±1.55]°, P〈0.01） because of reduced apical rotation and basal rotation. Conclusion LVtw have significantly reduced in DCM impact on global LV systolic function in patients with DCM. Two-dimensional ultrasound speckle-tracking imaging （STI） can evaluate LV twist. STI technique would be more robust in evaluation the LV twist in clinical use.