title: [Upgrading to resynchronization therapy in patients with heart failure after chronic right ventricular apical pacing].
abstract: OBJECTIVE
  To investigate the clinical efficacy of cardiac resynchronization therapy (CRT) through biventricular pacing in chronically right ventricular apical paced patients with heart failure.
  
  
  METHODS
  Ten chronically right ventricular apical paced patients with left ventricular ejection fraction (EF) ≤ 35% underwent CRT upgrading. And the follow-up period was over 12 months. Seven of them reported a significant improvement in their symptoms. Two patients died and one patient had no response. As compared with pre-CRT, CRT significantly improved NYHA classification, decreased left atrium diameter [(43 ± 5) mm vs (46 ± 7) mm], pulmonary arterial pressure [(42 ± 6) mm Hg vs (54 ± 13) mm Hg] and BNP [(184 ± 73) ng/L vs (545 ± 286) ng/L] (P < 0.05), improved left ventricular EF [(35 ± 5)% vs (32 ± 4)%]. Tissue Doppler imaging revealed the maximal difference of time to peak myocardial systolic contraction of 12 left ventricular segment shortened [(136 ± 28) ms vs (97 ± 18) ms], interventricular mechanical delay shortened [(52 ± 5) ms vs (31 ± 6) ms)] after upgrading.
  
  
  CONCLUSIONS
  CRT upgrading from right ventricular apical pacing may improve left ventricular function in patients with heart failure.
authors: Department of Cardiology, Tianjin Chest Hospital, Tianjin 300051, China.
authors: Feng-min
authors: FM
authors: Lu
authors: Dong-yan
authors: DY
authors: Wu
authors: Nai-kuan
authors: NK
authors: Fu
authors: Xin
authors: X
authors: Guan
authors: Jing
authors: J
authors: Xu