应变延迟指数对心脏再同步治疗患者术后反应的评估

目的探讨斑点追踪成像应变延迟指数（strain dyssynchrony index,SDI）对心脏再同步治疗（cardiac resynchronization therapy,CRT）患者术后反应的评估价值。方法采用常规超声心动图、组织多普勒成像和斑点追踪成像测定25例CRT治疗患者术前及术后6个月左室同步性和左室收缩功能。长轴SDI、径向SDI和圆周SDI分别通过左室长轴、径向和圆周应变峰值与收缩末期峰值差值之和的平均值计算得出;同时评估术前及术后6个月患者心功能的变化,CRT临床有反应定义为术后6个月心功能分级改善1级以上,CRT超声心动图有反应定义为术后6个月左室收缩末期容积减少≥15%。结果在评估CRT患者术后反应的3种SDI中,径向SDI≥6.6%时,预测CRT有反应的敏感性为82%,特异性为83%,曲线下面积0.88（P〈0.001）;圆周SDI≥3.2%和长轴SDI≥3.5%时,预测CRT有反应的曲线下面积分别为0.78和0.76（P〈0.05）。3种SDI均阳性预测CRT有反应率为100%,且它们均与左室收缩末期容积减少相关。结论径向SDI能较好地预测CRT患者术后反应,而联合使用3种SDI更能准确评估CRT患者术后的反应。

Effects of strain dyssynchrony index on response evaluations in patients with cardiac resyn-chronization therapy postoperatively

Objective To investigate the effects of strain dyssynchrony index（SDI）on response evaluations in patients with cardiac resynchronization therapy（CRT）postoperatively.Methods The synchrony and systolic function of left ventricle of 25 patients with CRT were evaluated with conven-tional echocardiography,tissue Doppler imaging and speckle tracking imaging before and 6 months after CRT procedure respectively.The longitudinal,radial and circumferential SDI was calculated as the average sum of difference between the corresponding peak strain and end-systolic peak respectively.Meanwhile,changes in patients’heart function before and 6 months after CRT proce-dure were also assessed according to clinical and echocardiographic performance.Response to CRT in clinic was defined as improvement of more than 1 class in heart function grade.Response to CRT in echocardiography was defined as reduction in left ventricular end-systolic volume ≥15% 6＆amp;nbsp;months after CRT.Results Among the 3 SDI,radial SDI≥6.6% was the best predictor of re-sponse to CRT,with sensitivity of 83%,specificity of 83%,and an area of 0.88 beneath the curve （P〈0.001 ）.Circumferential SDI≥3.2% and longitudinal SDI ≥3.5% were also found to be predictive of response to CRT,with areas of 0.78 and 0.76 beneath the curve,respectively（P＆lt;0. 05 ）.The rate of response to CRT in patients with 3 positive SDIs was 100%.Moreover,radial,cir-cumferential and longitudinal SDI at baseline were correlated with reduction of left ventricular end-sys-tolic volume.Conclusion The radial SDI can well predict patients’response to CRT postoperative-ly,whereas a combination of 3 SDI proves to be more accurate.