应变率成像对冠状动脉搭桥前后左心室形变及同步性的评价

Evaluation of left ventricular deformation and synchronicity before and after coronary artery bypass graft in patients with coronary artery disease using strain rate imaging

目的采用应变率成像（SRI）定量评价冠状动脉搭桥（CABG）前、后左室局部心肌收缩形变及同步性的变化，判断手术疗效，预测再狭窄。方法60例冠心病患者（病例组）分别于CABG术前1d、术后10d、1个月、3个月及6个月测量左前降支参与供血的室壁节段的收缩期应变率（SRsys）和应变（Ssys），计算收缩后应变指数（PSI）。40例健康志愿者作为对照组。比较术前与对照组及CABG术前、术后各时间点间SRsys、Ssys和PSI的变化情况。结果病例组SRsys和Ssys值较对照组显著减低。52例患者CABG术后1个月开始搭桥节段SRsys和Ssys逐渐增大，多数节段术后3个月和6个月时差异有统计学意义。病例组术前PSI较对照组明显增高，术后6个月，所有节段PSI值均明显回缩。超声检出8例患者发生术后再狭窄，其阳性预测值为75％。SRI参数法诊断室壁运动异常的敏感性高于传统的二维超声目测法，Ssys的敏感性高于SRsys。结论SRI可定量评价左室壁局部收缩形变及同步性，动态观察CABG手术前、后局部心肌功能的变化，判定术后疗效，发现术后再狭窄。

Objective To evaluate the capability of strain rate imaging（SRI） for monitoring regional systolic deformation and synchronicity of left ventricle after coronary artery bypass graft（CABG） and for evaluating effect of surgery and predicting restenosis. Methods The values of systolic strain rate（SRsys） ,systolic strain（Ssys） and post systolic strain index（PSI） in 5 segments supplied by left anterior descending coronary artery were measured in study group（60 patients with coronary artery disease） at 1 day before and 10 days, 1 month,3 months and 6 months after CABG. Forty healthy participants served as a baseline control group. The regional myocardial function before and after CABG was compared and analyzed. Results The peak values of SRsys and Ssys decreased before CABG in study group. In 52 of the 60 patients,SRsys and Ssys in the graft segments increased gradually and showed statistical significance in most studied segments at 3 and 6 months after surgery. In the above 52 patients, value of PSI increased before CABG and reduced significantly in all analyzed segments at 6 months after surgery. The restenosis of graft artery was suspected in 8 patients by SRI and the positive predictive value was 75%. The diagnosis sensitivity of SRI parameter method was higher than that of 2-dimensional echoeardiography and the sensitivity of Ssys was higher than that of SRsys. Conclusions SRI can be used to quantitatively assess the regional systolic deformation and synchronicity and monitor the improvement of myocardial function after CABG and determine the effect of surgery and predict restenosis of graft artery.