To determine whether left ventricular (LV) filling dynamics may be influenced by the type of LV morphological adaptation to arterial hypertension, pulsed Doppler mitral flow velocity recordings were performed in 30 hypertensive patients and in 18 normotensive subjects matched for age, body surface and heart rate. Peak early (E) and late (A) mitral flow velocity, A/E ratio (A/E), time to peak E (TP), acceleration (AHT) and deceleration half-time (DHT) of early mitral flow and isovolumic relaxation time (IRT) were measured. Compared with the control group, hypertensive patients showed prolonged IRT and DHT, increased A and A/E, whereas TP, AHT and E were unchanged. Hypertensive patients were classified into two subgroups on the basis of h/r ratio (h/r). Subgroup 1: 16 patients with normal h/r, less than 0.42, (five patients with increased LV mass index, greater than 129.2 g m-2, and 11 patients with normal LV mass index, less than 129.2 g m-2). Subgroup 2: 14 patients with increased h/r, greater than 0.42, (nine patients with increased LV mass index, greater than 129.2 g m-2 and five patients with normal LV mass index, less than 129.2 g m-2). In Subgroup 1 the cardiac output (CO) was increased and the total peripheral resistance (TPR) was unchanged in comparison with the control group. In Subgroup 2 the opposite haemodynamic profile was detected: normal CO and increased TPR.(ABSTRACT TRUNCATED AT 250 WORDS)