二维斑点成像技术评价扩张型心肌病患者心脏的纵向扭转

Left ventricular longitudinal rotation changes in patients with dilated cardiomyopathy detected by two-dimensional speckle tracking imaging

目的运用二维斑点成像技术评价扩张型心肌病患者（dilatedeardiomyopathy，DCM）与健康人间各参数的差异，证实DCM患者心脏纵向扭转的存在。方法搜集温州医学院附属第一医院2008年6月至2009年9月期间就诊的42例DCM患者作为DCM组和35例健康人作为对照组。两组均行常规超声心动图，检测左心房内径、左心室射血分数、过二尖瓣口舒张早期血流速度及舒张晚期血流速度。应用GEEchopac软件测量得到DCM组和对照组患者心尖四腔心的左心室壁的径向应变、应变率，左心室侧壁、室间隔、心尖及左心室整体纵向峰值扭转角度，对比两组问各参数的差异。结果（1）DCM组患者左心房内径、左心室收缩末期容积及左心室舒张末期容积均明显大于对照组（P均〈0．01），左心室射血分数明显低于对照组（P〈0．01），过二尖瓣口舒张早期血流峰速度／舒张晚期血流峰速度两组比较差异无统计学意义（P〉0．05）。（2）DCM组患者径向收缩期峰值应变以及收缩期、舒张早期、舒张晚期径向峰值应变率均明显低于对照组（P均〈0．01）。（3）对照组左心室侧壁的中间段、基底段以及心尖段呈逆时针扭转，而室间隔的基底段、中间段呈顺时针扭转，DCM组患者左心室侧壁的中间段呈逆时针扭转，而左心室侧壁基底段、心尖段、室间隔的基底段及中间段均呈顺时针扭转。DCM组患者左心室侧壁中间段和基底段、心尖段以及室间隔基底段的扭转角度均明显低于对照组（P均〈0．01）。对照组左心室呈较小角度的纵向逆时针扭转（0．76°±2．63。），而DCM组患者左心室呈纵向顺时针扭转（-1．58°±3．42°），两组扭转角度的差异有统计学意义（P〈0．01）。（4）DCM组患者左心室侧壁基底段、中间段与室间隔基底段扭转达峰时间差均与左心室的纵向峰值扭转角度具有相关性（r=0．409，P=0．007；r=0．396，P=0．009）。结论应用二维斑点成像技术，通过分析各节段应变、应变率及纵向扭转角度等参数，证实DCM患者心脏存在着一定角度的纵向顺时针扭转，DCM患者左心室侧壁基底段、中间段与室间隔基底段扭转达峰时间差可能是形成DCM患者心脏纵向扭转的一个原因。

Objective To assess the left ventricular longitudinal rotation （LR） in patients with dilated cardiomyopathy （DCM）. Methods Conventional echocardiography （GE-Vivid7） was performed in 35 healthy subjects and 42 DCM patients. Left atrial diameter was measured by M-mode echocardiography, left ventricular end-systolic, end-diastolic volume and left ventricular ejection fraction （LVEF） were calculated by bi-plane simpson＇s method. The peak velocity during early diastole （Ve） and late diastole （Va） of anterior mitral valve were measured by pulse-waved doppler, and the ratio Ve/Va was calculated. The peak radial systolic strain, strain rate in systolic, early and late diastolic periods were measured. Segmental LR and global LR were assessed using two-dimensional speckle tracking imaging （2D-STI）. Results The peak radial systolic strain, strain rate in systolic, early and late diastolic periods in DCM group were significantly lower than in healthy subjects, the rotation degrees of the middle and base lateral, the aoex and the base septum walls were significantlv lower than those of the healthy subjects. A prominent counterclockwise LR （0. 76°±2. 63°） was shown in healthy subjects while prominent clockwise LR （ -1.58°± 3.42° ） was present in DCM patients. The time delay between the left ventricular lateral wall and the base septum wall in DCM patients significantly correlated with the peak LR of the left ventrieular （ r = 0. 409, P 〈 0. 01 ; r = 0. 396, P 〈 0. 01 ）. Conclusions 2D-STI can be used to assess the LR in DCM patients and a clockwise LR is present in DCM patients which might be caused by the time delay between the left ventrieular lateral wall and the base-septum wall.