中文摘要：

目的应用三维斑点追踪技术（3D-STI）评价心脏再同步化治疗（CRT）前后患者的心肌力学特征。方法获取53例CRT患者左室环向、纵向及径向应变（CS、LS、RS）来评估左室心肌收缩力;测量并计算左室16节段环向、纵向及径向应变达峰时间标准差（Tcs-16SD、Tls-16SD、Trs-16SD）来评估左室机械同步性。结果 （1）CRT术前,CRT有效组左室心肌收缩力较无效组强,机械同步性较无效组差（P〈0.05）;（2）CRT术后,CRT有效组心肌收缩力及机械同步性均显著改善;CRT无效组心肌收缩力较术前改善（P〈0.05）,机械同步性与术前相比无明显差异（P〉0.05）;（3）在3D-STI指标中,Tls-16SD预测CRT术后疗效最有价值;（4）三维容积及心肌力学指标在观察者内、观察者间有较好的一致性。结论 CRT既能改善左室机械同步性,也能改善左室心肌收缩力,Tls-16SD能够有效地预测CRT疗效。

英文摘要：

Objective To evaluate the myocardial mechanics in patients undergoing cardiac resynchronization therapy（CRT）using three-dimensional speckle tracking imaging（3D-STI）before and 6 months after operation.Methods A randomized group of 53 CRT patients were prospectively enrolled.Three-dimensional circumferential strain（CS）,longitudinal strain（LS）,and radial strain（RS）were measured to assess LV myocardial contractility;the time to peak circumferential strain,longitudinal strain and radial strain of the LV 16 segments were measured and the standard deviations of them were calculated as Tcs-16 SD,Tls-16 SD and Trs-16 SD respectively to assess LV mechanical dyssynchrony.Results（1）Before CRT,the Response group had better LV myocardial contractility and poorer mechanical dyssynchrony than the Nonresponse group（P〈0.05）.（2）At 6-month follow-up,in Response group,both LV mechanical dyssynchrony and contractility were significantly improved;however,in the Nonresponse group,only LV myocardial contractility was slightly improved（P〈0.05）,while LV mechanical synchronization remained unchanged.（3）Of all indices in 3D-STI,The area under the ROC curve of Tls-16 SD expressed best value.（4）Indices of three-dimensional volume and myocardial mechanics has preferable reproducibility.Conclusions CRT can improve not only LV mechanical dyssynchrony but also its myocardial contractility.Tls-16 SD can effectively predict the response of CRT.