二维应变成像对冠心病患者的初步研究

目的 探讨冠心病患者心肌应变特点.方法 43例冠心病患者及35例正常人,分别获取左室短轴观二尖瓣环水平、乳头肌水平、心尖水平及心尖四腔观、二腔观,左室长轴观的高帧频图像,应用二维应变软件测量各个节段的二维应变值.结果 狭窄＜75%冠状动脉(冠脉)供血节段共96个,狭窄≥75%冠脉供血节段共147个.①狭窄≥75%冠脉供血节段与正常对照组比较,基底段、中间段及心尖段纵向收缩期峰值应变均明显减低,差异有统计学意义(P＜0.05);左室短轴(二尖瓣环、乳头肌及心尖水平)的绝大部分径向收缩期峰值应变及圆周收缩期峰值应变与正常对照组相比,差异无统计学意义(P＞0.05);②以纵向收缩期峰值应变≥-16.1%为截点值,预测冠脉狭窄≥75%的敏感性及特异性分别为78.7%和76.4%.③狭窄＜75%冠脉供血节段与正常对照组比较,纵向收缩期峰值应变、径向收缩期峰值应变及圆周收缩期峰值应变差异无统计学意义(P＞0.05).结论 当冠脉出现严重狭窄时,虽然二维超声心动图上无明显室壁运动异常,但反映心内膜下心肌功能的纵向应变已明显降低.

Two-dimensional strain in patients with coronary artery disease measured by speckle tracking echocardiography

Objective To assess the myocardial strain in patients with coronary artery disease by two dimensional strain echocardiography.Methods Forty-three patients with coronary artery disease and thirty five healthy subjects were included.High frame rate two-dimensional images were recorded from the left ventricular short-axis views at the levels of mitral annulus,papillary muscle and apex,and the apical four chamber view,two-chamber view and long-axis view of the left ventricle respectively.The longitudinal strain was measured in the apical views,radial strain and circumferential strain were measured in the left ventricular short-axis views using two-dimensional strain software.Results There were 96 segments whose flow was provided by coronary artery with stenosis＜75%,147 segments whose flow was provided by coronary artery with stenosis≥75%.The peak systolic longitudinal strain of different segments in patients with stenosis≥75% significantly reduced when compared with the control group(P＜0.05).The peak systolic radial strain and circumferential strain of different segments in patients with stenosis≥75% had no statistical difference compared with the control group(P＞0.05).When taking peak systolic longitudinal strain≥-16.1% as cut-off value for coronary artery stenosis of≥75%,the sensitivity and specificity were 78.7% and 76.4% respectively.There was no significant difference in systolic longitudinal strain,radial strain and circumferential strain between normal myocardium and stenosis＜75%(P＞0.05).Conclusions Although there are no evident regional wall motion abnormalities by two dimensional echocardiography,in patients with severe coronary artery stenosis,the longitudinal strain which can reflect the subendocardial myocardial function significantly reduced.