EFFECTS OF AGING ON LEFT-VENTRICULAR STRUCTURE AND FUNCTION

To better characterize the cardiac structural and functional changes that are associated with aging, Doppler-echocardiography was performed on 23 young (mean age, 25 years) and 30 old (mean age, 70 years) healthy normotensive subjects. Left ventricular cavity dimensions and wall thickness were determined and left ventricular mass index was calculated from M-mode echocardiograms. Stroke volume was calculated from Doppler-measured aortic flow. Diastolic filling was evaluated by pulsed Doppler echocardiography of mitral inflow. Posterior wall thickness (1.0 vs 0.8 cm, p < 0.05) and relative wall thickness (0.42 vs 0.35, p < .05) were significantly greater in the elderly subjects compared with the younger subjects. Left ventricular mass index increased on average 0.25 gm/m2/yr but was not significantly increased in the elderly compared with the younger subjects (89 vs 77 gm/m2). Shortening fraction and stroke volume did not differ between the two groups. Diastollic filling was dramatically altered with aging, and the elderly subjects demonstrated a doubling of percent atrial contribution (37% vs 19%, p < 0.0001) and halving of peak early-to-peak atrial velocity ratio (0.85 vs 1.77, p < .01).