EFFECTS OF AGING ON LEFT-VENTRICULAR FUNCTION DURING EXERCISE

Citation
M. Wajngarten et al., EFFECTS OF AGING ON LEFT-VENTRICULAR FUNCTION DURING EXERCISE, Cardiology in the elderly, 3(2), 1995, pp. 125-131
Citations number
36
Categorie Soggetti
Cardiac & Cardiovascular System","Geiatric & Gerontology
Journal title
ISSN journal
10583661
Volume
3
Issue
2
Year of publication
1995
Pages
125 - 131
Database
ISI
SICI code
1058-3661(1995)3:2<125:EOAOLF>2.0.ZU;2-C
Abstract
Aim: We set out to evaluate the effects of aging on left ventricular f unction during exercise. Methods: We studied healthy untrained elderly (n=14, 74.2 +/- 0.8 years old) and young (n = 12, 30.2 +/- 0.9 years old) men using radionuclide ventriculography at rest and during bicycl e exercise. The two age groups were compared at rest, at equivalent wo rkloads, and at peak exercise. Results: Heart rate was similar in both groups at workloads of 25, 50, and 75 W. At 75 W, left ventricular ej ection fraction was lower in the elderly. End-diastolic counts increas ed in the elderly group and decreased in the young group from rest to 25 W, indicating that the Frank-Starling mechanism was used in the eld erly. The peak diastolic filling rate was lower in the elderly. In con trast to the findings at rest, the first third of the filling rate was higher in the elderly at 75 W, mainly through the increase observed f rom rest to 25 W. The time to peak filling rate was shorter in the eld erly at 25 and 50 W. At peak exercise, the elderly had a lower peak wo rkload (76.8 +/- 1.8 versus 104.2 +/- 5.2 W), a lower heart rate (129. 1 +/- 5.6 versus 159.8 +/- 5.2 beats/min), and a lower ejection fracti on (71.7 +/- 0.9 versus 80.2 +/- 1.7%) than the young group but had a similar percentage change in stroke counts from baseline. Conclusions: The variation in left ventricular early diastolic filling at the onse t of exercise is enhanced by normal aging. The change in left ventricu lar stroke counts from rest to peak exercise, which reflects stroke vo lume behavior at peak exercise, is not affected by the aging process.