title: [Factors associated with the efficacy of cardiac resynchronization therapy in patients with chronic heart failure].
abstract: OBJECTIVE
  To observe the clinical effects of cardiac resynchronization therapy (CRT) in patients with chronic heart failure, and compare the clinical characteristics and outcome between responders and non-responders to define factors related to the efficacy of CRT.
  
  
  METHODS
  We retrospectively analyzed the data of patients underwent CRT-P/D implantation from January 2006 to December 2012 in our Hospital. All patients received long-term follow-up including NYHA classification, left ventricular ejection fraction (LVEF) and left ventricular internal dimension at end diastole (LVIDd).
  
  
  RESULTS
  A total of 204 patients were included (130 males, mean age (64.8 ± 11.9) years). The total response rate of CRT was 61.3%. Women, QRS duration ≥ 150 ms, and left bundle branch block (LBBB) were related with better response after CRT (all P < 0.05). Multivariate regression analysis showed that QRS duration was an independent determinant for CRT response. All-cause mortality rate was significantly lower in responder group than in non-responder group (P < 0.001).
  
  
  CONCLUSIONS
  In patients with chronic heart failure, women, QRS duration ≥ 150 ms, and LBBB are related with better CRT response rate post CRT. QRS duration ≥ 150 ms is an independent predictor of CRT response, and positive response is associated with lower all-cause mortality in this patient cohort.
authors.affiliation: Department of Cardiology, Second Affiliated Hospital, Zhejiang University, College of Medicine, Hangzhou 310009, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhou
authors.forename: Minfang
authors.initials: M
authors.lastname: Bao
authors.forename: Haiyan
authors.initials: H
authors.lastname: Lin
authors.forename: Shangwei
authors.initials: S
authors.lastname: Huang
authors.forename: Yifei
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Email: xugenghz@gmail.com.
authors.forename: Geng
authors.initials: G
authors.lastname: Xu
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block; D058406:Cardiac Resynchronization Therapy; D002318:Cardiovascular Diseases; D002908:Chronic Disease; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D016896:Treatment Outcome; D016277:Ventricular Function, Left