Doppler-derived left ventricular filling parameters are commonly used to evaluate diastolic function in hypertension, but the prevalence of abnormalities and their predictors are unknown. A group of 38 patients with mild essential hypertension whose antihypertensive drugs were stopped for 2 weeks prior to study, and 10 age-matched normotensive controls were studied. Using pulsed-wave Doppler echocardiography, velocity of early and atrial filling and their ratio, and half-times of acceleration and deceleration of early filling, were measured. As a group, hypertensives had lower early filling velocities (59.2 +/- 15.8 vs. 76.9 +/- 25.1 cm/s, p < 0.01), and higher late filling velocities (63.6 +/- 14.0 vs. 49.9 +/- 9.3 cm/s p < 0.01); the ratios of early/late filling (0.97 +/- 0.3 vs. 1.3 +/- 0.2, p < 0.01) was lower and deceleration half-times were prolonged (100.6 +/- 19.0 vs. 86.7 +/- 13.1 ms, p < 0.05). However, not all patients had an abnormal filling patterns. In 41%, ratios of early/late filling were greater-than-or-equal-to 1, and their velocities of early filling, late filling, acceleration half-times, and deceleration half-times were not significantly different from normal controls. There was no significant difference between those with a normal versus an altered filling pattern in respect to the severity and duration of hypertension, degree of hypertrophy, wall stress, or left ventricular dimension. None of the parameters of filling correlated well with age, left ventricular mass, systolic and diastolic pressure, peak systolic stress, or radius/thickness ratio. It is concluded that patients with hypertension as a group have abnormal Doppler-derived diastolic filling patterns, but that these abnormalities are not consistent; their presence and severity are unpredictable by clinical and echocardiographic indices of hypertensive heart disease.