The level of arterial pressure is not the sole determinant of cardiac and vascular adaptation to hypertension. In order to identify other factors (such as preload) we categorized by echocardiography, 55 never treated hypertensive patients and 39 age and gender-matched normal subjects, according to values of relative wall thickness and left ventricular mass index. Normal left ventricular anatomy was found in 63% hypertensives, whereas among hypertensives 7% had "concentric left ventricular remodeling", 16% concentric left ventricular hypertrophy and 14% had eccentric left ventricular hypertrophy. Systolic left atrial area (LA) was obtained from the four-chamber views. Mitral peak early diastolic (E) and late diastolic (A) flow velocity was assessed by Doppler. Because clinical characteristics such age and sex differed among the 5 groups only results of ANCOVA were reported (means +/- SD). [table: see text] We conclude that eccentric left ventricular hypertrophy may be associated with a parallel increase of left atrial area. Thus the association of an increase of cardiac volume in hypertensive patients with normal diastolic function suggest that volume overload may modulate the effect of arterial pressure on cardiac morphology.