Age-related modification of regional left ventricular filling in normal subjects

Left ventricular diastolic filling has been reported to be impaired with advancing age in normal subjects. To investigate the influence of regional ventricular diastolic asynchrony on global ventricular filling as a function of age and to assess the location of asynchronous regions within the left ventricle, radionuclide ventriculography was conducted in 48 normal subjects aged 15 to 73 years. Left ventricular regional filling was assessed by dividing the left ventricular region of interest into 4 quadrants, from which global, septal, apical and lateral time-activity curves and first-derivative curves were derived. Indexes of global left ventricular systolic function at rest did not correlate with age. However, indexes of global early diastolic filling declined significantly with age; peak filling rate normalized to end-diastolic volume (r = -0.42; p < 0.01), to stroke volume (r = -0.48; p < 0.001) and to peak ejection rate (r = -0.47; p < 0.001) decreased with advancing age. Global time to peak filling rate also increased with aging (r = 0.41; p < 0.01). Early diastolic asynchrony was measured as the sum of the absolute values of the time differences from global peak filling rate to that in each of three quadrants (delta TPFR). delta TPFR increased with age (r = 0.37; p < 0.01). Global peak filling rate normalized to end-diastolic volume (r = -0.40; p < 0.01), to stroke volume (r = -0.45; p < 0.01) and to peak ejection rate (r = -0.51; p < 0.001) decreased significantly with increasing delta TPFR. Time to peak filling rate of the lateral region occurred first (163 +/- 33 ms), followed by the apical (184 +/- 38 ms) and finally the septal region (195 +/- 35 ms). With regard to the sequence of regional filling, this suggests that a physiologic asynchrony exists in resting condition in normal subjects. Times to peak filling rate in the septal and apical regions were modestly correlated with age (r = 0.29; p < 0.05, r = 0.30; p < 0.05 respectively), but that in the lateral region did not show significant correlation with age. This may indicated that the effects of advancing age on the regional filling differ in regions within the left ventricle. These results suggest that aging alters left ventricular early diastolic filling in association with the increase in physiologic asynchrony.