Effect of Aging on Heart Rate and Rhythm in Subjects Free from Heart Disease: A 7-Year Prospective Study

Abstract

Thirty-six subjects (age 50 ± 10 years, range 24-65), free of cardiac disease, underwent 24-hour ambulatory electrocardiography (AECG) and maximum exercise stress testing at baseline and 7 ± 1 years later. At follow-up, weight, cholesterol, blood pressure, premature atrial complexes, premature ventricular complexes, and the percentage of subjects with premature ventricular complexes increased. No subject had repetitive forms or more than 1,000 premature ventricular complexes/24 h. Exercise tolerance, submaximum and maximum exercise heart rate, and minimum and average maximum heart rate on AECG decreased. The differences between hourly average maximum and minimum heart rates and between maximum exercise heart rate and maximum heart rate recorded on AECG decreased. These changes with age are not due to subclinical heart disease.