In this population-based study, long-term survival and prognostic factors were examined in 148 patients, 55 men and 93 women, from Olmsted County, Minnesota, who had permanent pacemaker implantation for sick sinus syndrome between 1969 and 1991. The overall survival for patients who had received a permanent pacemaker for sick sinus syndrome was significantly worse than that of an age- and sex-matched control population (p < 0.0001). The increased mortality was attributable at least in part to the presence of structural heart disease in patients with sick sinus syndrome who had undergone permanent pacemaker implantation (82 of 148 patients, 55%). Survival of patients with isolated sick sinus syndrome was comparable (p = 0.6729), whereas in patients with structural heart disease it was significantly worse than expected (p < 0.0001). Symptoms were eliminated or improved in 116 patients (78%) after pacemaker implantation. Multivariate analysis identified congestive heart failure, valvular heart disease, history of stroke or transient ischemic attack, and age as independent risk factors for mortality. However, there was a trend toward decreased survival in patients who had received ventricular pacing compared with those who had received dual-chamber pacing, but this difference did not reach statistical significance (p = 0.0556). The mode of pacing was not an independent risk factor (p = 0.23). The observed survival of patients aged < 80 years was significantly worse than expected (p < 0.0001), whereas that of patients aged > or = 80 years was similar to the expected (p = 0.22).