Natural History of Sinus Node Dysfunction After Permanent Pacemaker Implantation

To explore the natural history of symptomatic sinus node dysfunction after permanent pacemaker implantation, we followed up 71 patients (27 with sinus arrest, 27 with unexplained sinus bradycardia, 14 with the bradycardia/tachycardia syndrome, and three with sinoatrial block) for four to 14 years after placement of a permanent ventricular pacemaker. Survival rates at one, five, and ten years were 88%, 75%, and 70%, respectively. Overall mortality was 31%. Patients with congestive heart failure had significantly lower survival rates than those without (P less than .03). Survival rates were significantly lower in patients with coronary artery disease than in those with conduction system disease only (P less than .01). Fourteen of the 19 patients whose cause of death was known died of cardiovascular disease, ten of complications of coronary artery disease. Thus, survival after pacemaker implantation is adversely and profoundly influenced by underlying cardiovascular disease, particularly coronary artery disease and its complications.