PROLONGED ENDURANCE TRAINING PRESERVES CARDIAC COMPLIANCE WITH AGING

Abstract

PURPOSE Diastolic function and cardiac compliance decline with age and likely contribute to the development of heart failure in the elderly. However, it is uncertain if this decline is secondary to inactivity or due to senescence. Our hypothesis was that cardiac compliance is preserved in endurance trained elderly when compared to sedentary younger subjects. METHODS Eight healthy, rigorously screened, sedentary subjects (71±3 years) and 11 master endurance athletes (67±3 years, at least 20 years competitive record) underwent Swan-Ganz catheterization. Nineteen young sedentary subjects (29±6 years) who underwent the same protocol prior to this investigation served as additional controls. Pulmonary capillary wedge pressures (PCWP) and left ventricular enddiastolic volumes (LVEDV) using echocardiography were measured at baseline, during decreased cardiac filling using lower body negative pressure (LBNP, −15 and −30mmHg), and after saline infusion (15 and 30 ml/kg). Pressure-volume and Starling curves were constructed using a logarithmic and regression model respectively. RESULTS Master athletes had significantly higher stroke volumes for any given filling pressure, however ventricular contractility was similar. Left ventricular distensibility and dynamic compliance was substantially greater in the master athletes compared to sedentary old subjects and similar to that of the sedentary young group. CONCLUSIONS Prolonged, sustained endurance training appears to preserve cardiac compliance with aging. We speculate that exercise training may prevent or delay diastolic dysfunction or even heart failure in the elderly.