title: Ventricular pacing or dual-chamber pacing for sinus-node dysfunction.
abstract: BACKGROUND
  Dual-chamber (atrioventricular) and single-chamber (ventricular) pacing are alternative treatment approaches for sinus-node dysfunction that causes clinically significant bradycardia. However, it is unknown which type of pacing results in the better outcome.
  
  
  METHODS
  We randomly assigned a total of 2010 patients with sinus-node dysfunction to dual-chamber pacing (1014 patients) or ventricular pacing (996 patients) and followed them for a median of 33.1 months. The primary end point was death from any cause or nonfatal stroke. Secondary end points included the composite of death, stroke, or hospitalization for heart failure; atrial fibrillation; heart-failure score; the pacemaker syndrome; and the quality of life.
  
  
  RESULTS
  The incidence of the primary end point did not differ significantly between the dual-chamber group (21.5 percent) and the ventricular-paced group (23.0 percent, P=0.48). In patients assigned to dual-chamber pacing, the risk of atrial fibrillation was lower (hazard ratio, 0.79; 95 percent confidence interval, 0.66 to 0.94; P=0.008), and heart-failure scores were better (P<0.001). The differences in the rates of hospitalization for heart failure and of death, stroke, or hospitalization for heart failure were not significant in unadjusted analyses but became marginally significant in adjusted analyses. Dual-chamber pacing resulted in a small but measurable increase in the quality of life, as compared with ventricular pacing.
  
  
  CONCLUSIONS
  In sinus-node dysfunction, dual-chamber pacing does not improve stroke-free survival, as compared with ventricular pacing. However, dual-chamber pacing reduces the risk of atrial fibrillation, reduces signs and symptoms of heart failure, and slightly improves the quality of life. Overall, dual-chamber pacing offers significant improvement as compared with ventricular pacing.
authors.affiliation: Division of Cardiology, Mount Sinai Medical Center, and the University of Miami School of Medicine, Miami Beach, Fla, USA. glamas@msmc.com
authors.forename: Gervasio A
authors.initials: GA
authors.lastname: Lamas
authors.forename: Kerry L
authors.initials: KL
authors.lastname: Lee
authors.forename: Michael O
authors.initials: MO
authors.lastname: Sweeney
authors.forename: Russell
authors.initials: R
authors.lastname: Silverman
authors.forename: Angel
authors.initials: A
authors.lastname: Leon
authors.forename: Raymond
authors.initials: R
authors.lastname: Yee
authors.forename: Roger A
authors.initials: RA
authors.lastname: Marinchak
authors.forename: Greg
authors.initials: G
authors.lastname: Flaker
authors.forename: Eleanor
authors.initials: E
authors.lastname: Schron
authors.forename: E John
authors.initials: EJ
authors.lastname: Orav
authors.forename: Anne S
authors.initials: AS
authors.lastname: Hellkamp
authors.forename: Stephen
authors.initials: S
authors.lastname: Greer
authors.forename: John
authors.initials: J
authors.lastname: McAnulty
authors.forename: Kenneth
authors.initials: K
authors.lastname: Ellenbogen
authors.forename: Frederick
authors.initials: F
authors.lastname: Ehlert
authors.forename: Roger A
authors.initials: RA
authors.lastname: Freedman
authors.forename: N A Mark
authors.initials: NA
authors.lastname: Estes
authors.forename: Arnold
authors.initials: A
authors.lastname: Greenspon
authors.forename: Lee
authors.initials: L
authors.lastname: Goldman
mesh_terms: D000368:Aged; D001146:Arrhythmia, Sinus / Q000150:complications / Q000628:therapy*; D001281:Atrial Fibrillation / Q000209:etiology; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D006333:Heart Failure / Q000209:etiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial / Q000009:adverse effects; D011788:Quality of Life; D020521:Stroke / Q000209:etiology; D013318:Stroke Volume