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

Age-related reduction in global left ventricular filling has been reported. To assess how regional left ventricular filling is modified by aging, radionuclide ventriculography was conducted in 48 normal subjects aged 15 to 73 years. Left ventricular regional filling was assessed by dividing left ventricular region of interest into 4 quadrants, from which global (GLB), septal (SEP), apical (Ax) and lateral (LAT) time-activity curves and first-derivative curves were derived. Indexes of left ventricular systolic function at rest did not vary with age, but early diastolic filling significantly declined with age: peak filling rate normalized to end-diastolic volume (EDV/S), peak filling rate normalized to stroke volume (SV/s) and peak filling rate/peak ejection rate decreased (r = -0.42; p less than 0.01, r = -0.48; p less than 0.001, r = -0.47; p less than 0.001), time to peak filling rate increased (r = 0.41; p less than 0.01) with aging. 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 less than 0.01). Moreover, delta TPFR correlated with global peak filling rate (EDV/s), peak filling rate (SV/s) and peak filling rate/peak ejection rate (r = -0.40; p less than 0.01, r = -0.45; p less than 0.01, r = -0.51; p less than 0.001). Time to peak filling rate of the lateral region was the shortest (163 +/- 38 ms), followed by the global (179 +/- 36 ms), apical (184 +/- 38 ms) and finally the septal region (195 +/- 35 ms). This suggested that physiologic asynchrony with regard to the sequence of regional filling exists in resting condition in normal subjects. Time to peak filling rate in the septal and apical regions increased with age (r = 0.29; p less than 0.05, r = 0.30; p less than 0.05), but that in the lateral region did not correlate with age (r = 0.11). These regional differences correlated with increase in delta TPFR. Thus, aging alter left ventricular diastolic function, with reduced rate related to increased asynchronous early diastolic filling due to prolongation of time to peak filling rate in the septal and apical regions.