速度向量成像技术诊断冠心病左室节段功能的价值

The application of velocity vector imaging in diagnosing left ventricular segmental myocardial systolic function in patients with coronary heart diseases

目的应用超声速度向量成像技术(VVI)分析不同程度冠心病患者收缩期左心室心肌长轴及短轴各节段应变及应变率的变化特点,评价心肌缺血的室壁收缩功能。方法根据冠状动脉造影结果,左心室心肌分为正常组20例、缺血组15例和梗死组20例,所有受检者于超声心动图中取心尖四腔心、两腔心、左室短轴二尖瓣水平及乳头肌水平切面的动态图像,获得每个受检者各节段纵向及环向收缩期应变峰值(S max)和应变率峰值(SR max)。结果与正常组比较,缺血组及梗死组收缩期S max和SR max明显减低(P<0.01),梗死组收缩期S max和SR max较缺血组进一步减低(P<0.01)。以任意纵向节段S max<-12.41%、SR max<-0.84·s-1作为诊断心肌缺血的临界值,和以任意纵向节段S max<-6.65%、SR max<-0.67·s-1作为诊断急性心肌梗死的临界值,可获得最佳敏感度及特异度。以任意环向节段S max<-13.12%、SR max<-1.25·s-1作为诊断心肌缺血的临界值,和以任意环向节段S max<-7.18%、SR max<-0.79·s-1作为诊断急性心肌梗死的临界值,可获得最佳敏感度及特异度。结论VVI技术方便、重复性好,具有准确定量评价心肌梗死心肌缺血的临床应用价值,尤其是应变和应变率能提供更多有价值的信息。

Objective To assess the left ventricular （LV） long and short axis systolic functions in patients with coronary atherosclerotic heart disease （CAD） by velocity vector imaging （VVI）. Methods Twenty control participants and 35 patients with CAD were examined, including 20 patients with myocardial infarction and 15 with myocardial ische- mia. According to the results of coronary arteriography, the myocardial segments of the LV of CAD patients were divided into three groups： ischemia, infraction and normal. Dynamic imaging was performed on all subjects. The long axis views of apical 4 - chamber and 2 - chamber of left ventricle and short axis views at the level of mitral valve and papillary muscle were acquired with Siemens Sequoia 2000 uhrasound system. The systolic peak strain （ Smax）, systolic strain rate （ SRm~ ） in every cycle were measured. Results Compared to the control group, Smax and SRm= in ischemia and infarction groups were significantly impaired in CAD patients. The optimal sensitivity and specificity were obtained with strain and strain rate cutoffs of - 12. 41% and -0. 84·s-1 , respectively, for detection of longitudinal ischemic segments; of -6. 65% and -0. 67·s-1, respectively, for detection of longitudinal infarcted segments. The optimal sensitivity and specificity were obtained with strain and strain rate cutoffs of - 13.12% and - 1.25 ~ s-1, respectively, for detecting longitudinal ischemic segments ; and of - 7. 18% and - 0. 79·s-1, respectively, for detecting longitudinal infracted segments. Con- clusion Utilizing VVI, the longitudinal and circumferential strain, strain rate in CAD patients are easy to obtain and re- producible, providing valuable evidences for detecting ischemia and infarction.