Exercise testing in the diagnosis of sick sinus syndrome in the elderly: implications for treatment.

Twenty-three elderly patients underwent treadmill exercise testing to fatigue; 11 patients had sick sinus syndrome (7 males, 4 females; age range 71-91 years; mean, 78 years); 12 elderly persons were controls (5 males, 7 females; age range 70-93 years; mean, 76 years). All were euthyroid. The study showed that patients with sick sinus syndrome compared with the control group demonstrated a lower resting heart rate, a smaller increase in heart rate during exercise, poorer exercise tolerance, and differences in heart rate during the recovery phase. The value of the effort test in relation to the diagnosis of sick sinus syndrome is discussed, together with its possible implications in the choice of pacemaker.