Evaluation of Myocardial Contractility in Healthy Elderly Men by Dynamic Exercise Echocardiography
1981 Volume 18 Issue 2 Pages 88-96
Details
1981 Volume 18 Issue 2 Pages 88-96
The aim of this study is to compare the myocardial contractility of the healthy elderly men to that of healthy young men, all of them underwent submaximal treadmill stress tests which were negative. The study population consists of 29 healthy young (young group) and 18 old men (old group). Their average ages were 28.5±4.3 (mean±SD) in the former and 68.5±5.1 in the latter. All of them performed the graded exercise of bicycle ergometer in the supine position. Echocardiograms of the left ventricular internal dimensions with simultaneous measurements of external pulse recording were successfully obtained from all of them at rest and during the steady state of the exercise level of 75 Watts.
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 pressure, however, increased more markedly in the old than the young group during exercise (P<0.01), while the values at rest were not different in both groups. As to the ejection phase indices at rest, the values of stroke dimension (SD) and of mean rate of circumferential fiber shortening (VCF) in both groups were not statistically different, while those of ejection fraction (EF) and of normalized VCF were significantly smaller in the old (65.4±5.7%, 1.01±0.12sec-1, respectively) than in the young group (70.7±5.3, 1.14±0.13, respectively) (p<0.01). It revealed, however, that EF and normalized VCF did not show any significant difference in both groups of values, when they were corrected by the left ventricular end-diastolic internal dimension. During exercise, all of these four indices increased their values significantly in both groups and the changes were more marked in the old than the young group (p<0.05-0.01). Therefore, the values in EF and normalized VCF during exercise showed no significant difference in both groups.
These results suggest that healthy elderly men have no reduction in myocardial contractility as compared to that in healthy young subjects, judged by the echocardiographic measurements. It is also suggested that these measurements can be used as the tool to differentiate the normal heart and the latent cardiac dysfunction.
