title: Atrioventricular nodal ablation in atrial fibrillation: a meta-analysis of biventricular vs. right ventricular pacing mode.
abstract: OBJECTIVE
  For patients with refractory atrial fibrillation (AF) undergoing atrioventricular nodal ablation (AVNA), initial single-chamber right ventricular (RV)-only pacing is standard. Given the deleterious effects of chronic RV-only pacing, the impact of an initial biventricular (BiV) pacing strategy post-ablation is of interest.
  
  
  RESULTS
  We conducted a meta-analysis to determine the effect of BiV vs. RV-only pacing in patients undergoing AVNA for refractory atrial fibrillation. A search of multiple electronic databases identified 921 reports, which included four randomized controlled trials (n = 534). Mean New York Heart Association (NYHA) class was 2.3 and mean left ventricular ejection fraction (LVEF) was 44%. When compared with RV-only pacing, BiV pacing was not associated with reduced mortality [risk ratio 0.85, 95% confidence interval (CI) 0.40-1.82, P = 0.68]. In three studies comprised of patients with left ventricular systolic dysfunction (mean EF 41 ± 3%), BiV pacing demonstrated a non-significant reduction in cardiac mortality (risk ratio 0.59, 95% CI 0.25-1.39; P = 0.23). Compared with RV-only pacing, BiV pacing was associated with significant improvement in symptoms [Minnesota Living with Heart Failure Questionnaire (MLWHFQ) 2.72 points fewer, 95% CI 1.45-3.99] and increased LVEF (+2.6%, 95% CI 1.69-3.44), but no significant change in 6 min walk distance (6MWD) (5.02 ms more, 95% CI -1.56 to 11.59; P = 0.13).
  
  
  CONCLUSIONS
  In patients with refractory AF undergoing AVNA, BiV pacing was not associated with significantly improved survival when compared with RV-only pacing. A modest, but significant improvement in structural and functional response to BiV pacing was observed.
authors.affiliation: Department of Medicine and the Cardiac Arrhythmia Service, Massachusetts General Hospital, Boston, MA 02411, USA.
authors.forename: Neal A
authors.initials: NA
authors.lastname: Chatterjee
authors.forename: Gaurav A
authors.initials: GA
authors.lastname: Upadhyay
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Ellenbogen
authors.forename: David L
authors.initials: DL
authors.lastname: Hayes
authors.forename: Jagmeet P
authors.initials: JP
authors.lastname: Singh
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D001283:Atrioventricular Node / Q000473:pathology*; D058406:Cardiac Resynchronization Therapy; D017115:Catheter Ablation; D016001:Confidence Intervals; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D011788:Quality of Life; D012306:Risk; D011795:Surveys and Questionnaires; D017211:Treatment Failure; D014481:United States