超声斑点追踪显像技术评价扩张型心肌病左室扭转特点

Evaluation of the left ventricular twist in dilated cardiomyopathy by two-dimensional ultrasound speckle tracking imaging

目的应用超声斑点追踪显像技术(STI)探讨扩张型心肌病患者(DCM)左室旋转(LVrot)和左室扭转(LVtw)运动特点及左室运动同步性,分析其与常规左室收缩功能参数的关系。方法选择24例DCM患者及与之年龄匹配的24例正常人为研究对象,经胸采集标准短轴左室心尖位、心底位的图像并存储,运用EchoPAC超声工作站进行脱机分析。计算左室心尖位旋转角度、心底位旋转角度、左室扭转峰值及相应达峰时间。结果 DCM患者扭转运动主要表现为心底位顺时针旋转和心尖位逆时针旋转,心脏整体表现为心动周期内逆时针方向为主的扭转运动,正常人也主要表现为心底位顺时针旋转和心尖位逆时针旋转及心脏整体逆时针方向为主的扭转运动。但DCM患者左室扭转峰值[(4.62±1.55)°/(13.85±2.77)°,P<0.001]显著减低。DCM患者左室扭转峰值(peak tw ist,Ptw)与左室射血分数(LVEF)正相关(r=0.534,P<0.05)。DCM患者心尖位和心底位旋转角度达峰时间不一致,差异有统计学意义(P<0.05)。结论 DCM在短轴方向表现为左室旋转和扭转运动减低及整体运动不同步的特点。Ptw减低显示左室收缩功能减低,Ptw与常规左室收缩功能参数LVEF正相关。

Objective To assess the characters of left ventricular rotation（LVrot） and left ventri-cular twist（LVtw） and the LV synchrony in dilated cardiomyopathy（DCM） by two-dimensional ultrasound speckle-tracking imaging（STI）,to study the relationship between the twist and conven-tional echocardiography parameters of LV systolic function.Methods Twenty-four patients with dilated cardiomyopathy and twenty-four healthy volunteers were recruited.High frame rate two-dimensional images were recorded from the left ventricular short-axis views both of the basal and apical planes.Digitals stored in a hard disk for offline analysis using the EchoPAC software.Basal and apical peak value of left ventricular rotation（Prot）,peak value of left ventricular twist（Ptw） and time to Prot and Ptw were calculated.Results Seen from the apex,LV performed a wringing motion with a clockwise rotation at the base and counterclockwise rotation at the apex.The whole heart mainly performed a wringing motion with counterclockwise rotation within the cardiac cycle.LV twist was decreased significantly in DCM（4.62±1.55） °/（13.85±2.77） °,P0.001].In DCM,LVEF was correlated with LVtw（r﹦0.534 and 0.517,P0.05）.In DCM,there was statistics in the time to Prot between the basal and apical level of the left ventricular（P0.05）.Conclusion From the left ventricular short-axis view,Lvrot and Lvtw are reduced significantly and the global LV is not synchrony in DCM.The decreased Ptw illustrates the decreased LV systolic function;Ptw is correlated with conventional echocardiography parameters of LV systolic function LVEF.