title: [Predict value of time to peak of systolic velocity derived from velocity vector imaging on cardiac resynchronization therapy response in refractory heart failure patients].
abstract: OBJECTIVE
  To investigate the impact of cardiac resynchronization therapy (CRT) on left ventricular systolic function evaluated by velocity vector imaging (VVI) in refractory heart failure patients and the predictive value of VVI on CRT responses.
  
  
  METHODS
  This study included 38 patients with medically refractory heart failure (HF) patients underwent CRT in our department from May 2007 to April 2011. Left ventricular long axis dyssynchrony indexes including time to peak of systolic velocity (Ts max-min), standard deviation of the time to peak of systolic velocity (Ts-SD) before and at 3-6 months post CRT. CRT response was defined as 15% decrease in left ventricular end-systolic volume. ROC curve and the area under the curve (AUC) were calculated.
  
  
  RESULTS
  Twenty-four patients were defined as responder. No significant difference was observed between responders and non-responders in medical therapy. When using Ts max-min to predict response, the AUC of ROC curves was 0.76 ± 0.07. The sensitivity and specifity was 70.8% and 77.8% respectively with Ts max-min ≥ 124.0 ms. When using Ts-SD to predict response, the AUC of ROC curves was 0.82 ± 0.07. The sensitivity and specifity was 79.2% and 71.2% respectively with Ts-SD ≥ 40.5.
  
  
  CONCLUSIONS
  Ts-SD is a useful index to predict CRT response in refractory HF patients.
authors.affiliation: Department of Cardiology, Chinese People's Liberation Army's General Hospital, Beijing 100853, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Guo
authors.affiliation: Email: wyt301@sina.com.
authors.forename: Yutang
authors.initials: Y
authors.lastname: Wang
authors.forename: Guang
authors.initials: G
authors.lastname: Zhi
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Zhaoliang
authors.initials: Z
authors.lastname: Shan
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Shi
authors.forename: Kun
authors.initials: K
authors.lastname: Lin
mesh_terms: D019540:Area Under Curve; D058406:Cardiac Resynchronization Therapy; D006333:Heart Failure; D006801:Humans; D012372:ROC Curve; D013318:Stroke Volume; D013599:Systole; D016277:Ventricular Function, Left