Aging and the effect of increased after-load on left ventricular contractile state.

Abstract

Hemodynamic and contractile states were studied echocardiographically in 10 young (28 +/- 3 yr) and 10 elderly (67 +/- 4 yr) male subjects at rest and during upright isometric exercise which involved the hands, hips, legs, and lower back muscle groups (deadlift) at 30% of maximum voluntary contraction for 3 min. During deadlift, both groups showed similar and significant increases in blood pressure and heart rate, compared to the resting values. Ejection fraction at rest did not differ significantly between the two groups. During deadlift, it remained unchanged in the elderly white ejection fraction increased significantly in the younger subjects. No significant changes in left ventricular end-diastolic volume occurred in either group during deadlift. End-systolic volume remained unchanged in the elderly while it decreased significantly in the younger subjects. These data indicate that cardiovascular responses and contractile state in normal young men and normal exercise-trained elderly subjects were augmented during upright sub-maximal isometric deadlift exercise, utilizing large muscle mass. However, left ventricular contractility increased less in the elderly subjects compared to the younger subjects.