Systolic time intervals are evaluated by polygraphic method in a group of patients with systemic arterial hypertension. An increase of pre-expulsion period (P.E.P.) was found by relative increase of isometric contraction time (I.C.T.) in subjects with "old" hypertension; no significative differences and found in subjects with recent hypertension and in controls. The A. have attributed this alterations to a compensation mechanism of the left ventricle that extends the time of its internal pressure increase to win the resistence of excessive pressure being in aorta, that influences the after load value. According to the Authors', in absence of left ventricular insufficiency, that alteration is not accompanied by other significant mechanocardiographic modifications.