Background: The present study was designed to assess the underlying mechanism of decline in effort capacity seen with aging. Methods: We analyzed 250 healthy senior patients (≥65 years) with an ejection fraction ≥60% who underwent a stress echocardiogram test. The seniors (aged 65–94) were divided into 3 equal age groups (groups 1, 2, and 3), and their echo characteristics at rest and peak exercise (measured and calculated) were compared. Results: Diastolic function at rest declined significantly (E lateral, E septal, E/E′, A) with age, while other rest parameters were similar. There was a significant reduction in peak cardiac output (CO) associated with age (time × age group interaction; P <.05), which was attributed to the combination an attenuated stroke volume (SV) and heart rate (HR) response. The decline in effort capacity with age was the product of the combined effect of cardiac (reduced LVEDV and HR response) and noncardiac (reduction in arteriovenous difference; P =.02 for interaction) causes. Conclusion: The cardiovascular system undergoes several age-related changes. Decline in effort capacity is an ongoing process of aging and consists of several changes in the cardiac and noncardiac systems, comprising a decline in CO and its components, specifically the peak exercise LVEDV, peak heart rate, and the ability of the muscles to extract enough oxygen for the necessary effort.
- exercise tolerance
- stress echocardiography