Abstract
To assess the effect of aging on left ventricular function, we performed two dimensional echocardiography at rest and during supine bicycle exercise. The study consists of 10 healthy young men (young group) and 9 healthy elderly men (elderly group), all of whom underwent submaximal treadmill stress tests with negative results. The average ages were 26.9±3.4 (mean±S.D.) and 69.4±5.5 years old. Satisfactory two dimensional echocardiographic views were obtained with simultaneous external pulse recording at rest and diring the steady state of exercise at 75 watts. There were no wall-motion abnormalities before and during exercise in both groups. End-diastolic and end-systolic short axis areas of the left ventricle were analyzed at the level of the papillary muscle.
Changes in heart rate and peripheral vascular resistence during exercise, compared to resting state, showed no significant difference in both groups. Systolic and diastolic blood pressures, however, increased more markedly in the elderly than in the young group during exercise (p<0.05), while left ventricular ejection time shortend more markedly during exercise in the young than in the elderly group (p<0.01). End-diastolic and end-systolic short axis areas did not show significant difference at rest or significant changes during exercise in both groups. The fractional change in short axis area and mean velocity of the fractional change in short axis area, both considered useful indices of myocardial contractility in the absence of wall-motion abnormalities did not show significant difference at rest in both groups. During exercise, the latter increased significantly in the young group (p<0.05), although its changes from the resting state did not show significant difference in both groups.
These results suggest that myocardial contractility in the healthy elderly men is not decreased in comparison to that in the healthy young subjects. Two dimensional echocardiography during dynamic exercise is considered an useful noninvasive method in evaluating the cardiac function in elderly men.
