Abstract
To study the effects of age on the left ventricular diastolic performance in normal individuals, atrial filling fraction (AFF) and rapid filling fraction (RFF) were determined using the aortic root echocardiogram in 14 young (Nl) and 29 middle-aged males (N2) at rest and immediately after a 3-min isometric handgrip exercise (IHE)at 30% maximal voluntary contraction. The two groups showed comparable increases in heart rate and blood pressure during IHE. At rest, AFF measured 36 ± 7 vs. 34 ± 8%, p < 0.05 in N1 and N2 respectively. But RFF was lower in N2 than in Nl (54 ± 10 vs. 68 ± 13%, p < 0.05, respectively). Nl showed no significant changes in AFF or RFF during IHE, but N2 showed an increase in AFF (from 36 ± 7 to 39 ± 9%, p < 0.05) and a decrease in RFF(from 54 ± 10 to 48 ± 11 %, p < 0.05). Increased afterload during isometric exercise caused an increase in AFF with simultaneous decrese in AFF, presumably reflecting mobilization of the left ventricular booster pump action in older individuals.