Ventricular pacing or dual-chamber pacing for sinus-node dysfunction.
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.
Lamas
Gervasio A
GA
Division of Cardiology, Mount Sinai Medical Center, and the University of Miami School of Medicine, Miami Beach, Fla, USA. glamas@msmc.com
Lee
Kerry L
KL
Sweeney
Michael O
MO
Silverman
Russell
R
Leon
Angel
A
Yee
Raymond
R
Marinchak
Roger A
RA
Flaker
Greg
G
Schron
Eleanor
E
Orav
E John
EJ
Hellkamp
Anne S
AS
Greer
Stephen
S
McAnulty
John
J
Ellenbogen
Kenneth
K
Ehlert
Frederick
F
Freedman
Roger A
RA
Estes
N A Mark
NA
Greenspon
Arnold
A
Goldman
Lee
L
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