title: Accelerated graft dysfunction in heart transplant patients with persistent atrioventricular conduction block.
abstract: OBJECTIVE
  Bradyarrhythmia following heart transplantation is common-∼7.5-24% of patients require permanent pacemaker (PPM) implantation. While overall mortality is similar to their non-paced counterparts, the effects of chronic right ventricular pacing (CRVP) in heart transplant patients have not been studied. We aim to examine the effects of CRVP on heart failure and mortality in heart transplant patients.
  
  
  RESULTS
  Records of heart transplant recipients requiring PPM at St Vincent's Hospital, Sydney, Australia between January 1990 and January 2015 were examined. Patient's without a right ventricular (RV) pacing lead or a follow-up time of <1 year were excluded. Patients with pre-existing abnormal left ventricular function (<50%) were analysed separately. Patients were grouped by pacing dependence (100% pacing dependent vs. non-pacing dependent). The primary endpoint was clinical or echocardiographic heart failure (<35%) in the first 5 years post-PPM. Thirty-three of 709 heart transplant recipients were studied. Two patients had complete RV pacing dependence, and the remaining 31 patients had varying degrees of pacing requirement, with an underlying ventricular escape rhythm. The primary endpoint occurred significantly more in the pacing-dependent group; 2 (100%) compared with 2 (6%) of the non pacing dependent group (P < 0.0001 by log-rank analysis, HR = 24.58). Non-pacing-dependent patients had reversible causes for heart failure, unrelated to pacing. In comparison, there was no other cause of heart failure in the pacing-dependent group.
  
  
  CONCLUSIONS
  Permanent atrioventricular block is rare in the heart transplant population. We have demonstrated CRVP as a potential cause of accelerated graft failure in pacing-dependent heart transplant patients.
authors: St Vincent's Hospital, Suite 802, 438 Victoria St., Darlinghurst, NSW 2010, Australia dr.wl.lee@gmail.com.
authors: William
authors: W
authors: Lee
authors: St Vincent's Hospital, Suite 802, 438 Victoria St., Darlinghurst, NSW 2010, Australia.
authors: Andre
authors: A
authors: Tay
authors: St Vincent's Hospital, Suite 802, 438 Victoria St., Darlinghurst, NSW 2010, Australia.
authors: Bruce D
authors: BD
authors: Walker
authors: St Vincent's Hospital, Suite 802, 438 Victoria St., Darlinghurst, NSW 2010, Australia.
authors: Dennis L
authors: DL
authors: Kuchar
authors: St Vincent's Hospital, Suite 802, 438 Victoria St., Darlinghurst, NSW 2010, Australia.
authors: Christopher S
authors: CS
authors: Hayward
authors: St Vincent's Hospital, Suite 802, 438 Victoria St., Darlinghurst, NSW 2010, Australia.
authors: Phillip
authors: P
authors: Spratt
authors: St Vincent's Hospital, Suite 802, 438 Victoria St., Darlinghurst, NSW 2010, Australia.
authors: Rajesh N
authors: RN
authors: Subbiah
mesh_terms: D000328:Adult; D054537:Atrioventricular Block / Q000503:physiopathology*; D001315:Australia; D001919:Bradycardia / Q000209:etiology / Q000628:therapy; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects* / Q000379:methods; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000209:etiology / Q000401:mortality*; D016027:Heart Transplantation; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D055031:Primary Graft Dysfunction / Q000503:physiopathology*; D012189:Retrospective Studies; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology
keywords: Complete heart block; Heart failure; Heart transplant; Pacemaker; Pacemaker dependent; Pacing-induced cardiomyopathy