Aging influences pulmonary venous flow and mitral inflow velocities. The duration of pulmonary venous atrial reversal flow exceeds that of the mitral inflow A wave in patients with left ventricular end-diastolic pressures greater than 15 mm Hg. The objective of this study was to investigate the effect of age on the difference between the duration of pulmonary venous atrial reversal flow and that of the mitral inflow A wave in a large number of normal individuals. Pulsed wave Doppler transthoracic echocardiograms of the pulmonary venous flow and the transmitral inflow with respiratory monitoring were made of 72 normal volunteers (40 women) ranging in age between 23 and 84 years. The differences in the durations of pulmonary venous atrial reversal flow and mitral inflow A wave were measured and their correlation with age assessed. Age was not highly correlated with the duration of pulmonary venous atrial reversal flow (r = 0.25) nor the duration of the mitral inflow A wave (r = 0.33). The duration of pulmonary venous atrial reversal flow exceeded the duration of the mitral inflow A-wave flow only in three (4%) of 72 subjects, and age was not related to the index in this group (r = -0.16; p = 0.19). The difference in durations was not significantly affected by the phase of respiration. Men had higher values on all measurements than women. The difference between the pulmonary venous atrial reversal duration and the mitral inflow A-wave duration is independent of age and thus may be used as a reliable index of left ventricular end-diastolic pressure, even in elderly patients.