title: [Incidence and causes of nonresponse to cardiac resynchronization therapy in patients with congestive heart failure].
abstract: OBJECTIVE
  To observe the incidence and explore the potential factors of nonresponse to cardiac resynchronization therapy(CRT)in patients with severe chronic congestive heart failure.
  
  
  METHODS
  CRT was performed in 119 patients with NYHA function class III-IV and left ventricular ejection fraction ≤ 35% [96 men and 23 women, age (60.5 ± 11.3) years].
  
  
  RESULTS
  Seven patients died for different reasons between 1 - 6 months post CRT and clinical and echocardiographic (Echo) data at 6 months post CRT were analyzed from the remaining 112 patients. The incidence of nonresponse to CRT was 28.57%. Compared to the response group, complete right bundle branch block, longer course of congestive heart failure, higher pulmonary systolic pressure and serum creatinine level and non-optimal target vessels positioning of the left ventricle lead (the great cardiac vein and the middle cardiac vein) were the independent predictors for nonresponse after CRT (all P < 0.05). Compared with nonresponse group, the dosages of digoxin and diuretics used for heart failure were significantly reduced in response group (P < 0.01).
  
  
  CONCLUSIONS
  The incidence of nonresponse after CRT was 28.57% in this patient cohort. Higher pulmonary systolic pressure and serum creatinine level and non-optimal target vessels positioning of the left ventricle lead (the great cardiac vein and the middle cardiac vein) were the independent predictors for nonresponse after CRT.
authors.affiliation: Department of Cardiology, General Hospital of Shenyang Military Region of People's Liberation Army, Shenyang 110016, China.
authors.forename: Dong-mei
authors.initials: DM
authors.lastname: Wang
authors.forename: Ya-ling
authors.initials: YL
authors.lastname: Han
authors.forename: Hong-yun
authors.initials: HY
authors.lastname: Zang
authors.forename: Hai-bo
authors.initials: HB
authors.lastname: Yu
authors.forename: Wei-wei
authors.initials: WW
authors.lastname: Zhou
authors.forename: Dong-hong
authors.initials: DH
authors.lastname: Zhang
authors.forename: Yun
authors.initials: Y
authors.lastname: Tian
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D058406:Cardiac Resynchronization Therapy; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome