应变延迟指数定量评价无室壁运动异常的冠心病患者左心室收缩同步性

Evaluation of left ventricular dyssynchrony in coronary heart disease without visual segmental wall motion abnormalities by strain delay index

目的探讨应变延迟指数（SDI）评价无室壁运动异常的冠心病患者左一12,室同步性的临床价值。方法135例冠心病可疑的胸痛患者在冠状动脉造影前分别接受常规二维超声和斑点追踪显像检查，用二维应变软件分析心尖长轴观、心尖两腔观和四腔观以及左室短轴观基底水平、乳头肌水平、心尖水平的图像，测量心电图QRS波起点至左室在心尖长轴观上的收缩期纵向应变达峰时间（Tssl）及胸骨旁短轴观上的收缩期径向和环向应变达峰时间（Tssr，Tssc）。计算左室各节段达峰时间标准差（TsslSD，TssrSD，Tssc—SD）及节段达峰时间最大差值（TsslDif，Tssr—Dif，Tssc—DiD，同时测量18个一12,肌节段纵向、径向及环向应变峰值与收缩末应变的差值之和作为纵向、径向及环向延迟指数（LSDI、RSDI及CSDI）。结果根据冠状动脉造影结果将患者分为重度狭窄组、轻度狭窄组和对照组。冠脉重度狭窄组SDI、Tssl—SD、Tssl—Dif及Tssr—SD、Tssr—Dif较对照组显著增加（P〈0．001或P〈0．05）；重度狭窄组与轻度狭窄组问Tssl—SD、Tssl—Dif及LSDI、RSDI、CSDI差异有统计学意义（P〈0．05）；轻度狭窄组与对照组相比，除Tssr—SD外所有不同步参数差异均无统计学意义（PD0．05）。R（）c曲线分析显示5种不同步指标检测重度冠脉狭窄的准确性依次为I。SDI〉RSDI〉CSDI〉Tssl—sD〉TsslDif（曲线下面积分别为0．891、0．797、0．666、0．580、0．556）。以LSDI≥-12．67％为截断值检测重度冠脉狭窄，具有最高的诊断价值（敏感性和特异性分别为80．6％和86．7％）。结论SDI能定量评价冠心病患者左室同步性，LSDI能更敏感地检测无明显节段性室壁运动异常的重度冠脉狭窄患者左室不同步。

Objective To assess the left ventricular dyssynchrony in coronary artery disease（CAD） without visual segmental wall motion abnormalities using strain delay index （SDI）. Methods A total of 135 patients under suspicion of CAD were recruited in this study. Two dimensional echocardiography was performed to collect dynamic images of left ventricular apical long axis views, tow-chamber views, four chamber views and parasternal short axis mitral views, papillary views and apical views. The time to minimal systolic longitudinal, radial, circumferential strain （Tssl, Tssr and Tssc） were measured from the start point of QRS wave in electrocardiogram. The left ventricular segmental standard deviation （Tssl-SD, Tssr-SD, Tssc-SD）, maximal difference （Tssl-Di[, Tssr-Dif, Tssc-Dif） and longitudinal, radial, circumferential SDI （LSDI, RSDI, CSDI） of 18 left ventricular segments were calculated. Results According to coronary angiography results, patients were divided into three groups ： severe stenosis group, mild stenosis group and control group. Compared with the other two groups, SDI and Tssl-SD, Tssl-Dif were decreased in severe stenosis group （ P ~0. 001 or P %（）. （15）. However,there were not significant differences between the mild stenosis group and the control group except Tssr SD. The receiver operating characteristic （R（）C） curves analysis demonstrated that LSDI had the highest accuracy and TssI-SD had the lowest accuracy for detecting severe CAD （areas under the curve were 0. 891,0. 797, 0. 666, 0.580 and 0. 556 respectively）. High sensitivity and specificity （80. 6% and 86.7% ,respectively） were shown when using - 12.67% as a cutoffpoint of LSI-）I to diagnose severe CAD. Conclusions SDI can be helpful for assessing the left ventricular dyssynchrony in patients without visual segmental wall motion abnormalities,and LSDI is the most effective parameler to detecting severe CAD.