Peripheral vascular resistance, arterial blood pressure, and left ventricular hypertrophy (LVH) are closely related. In systemic hypertension, hemodynamic changes in systolic and diastolic function accompany LVH. Both of these cardiac functions are detected with echocardiography and were measured during this study in 23 essential hypertension patients treated with 2.5-5 mg of cilazapril daily for 6 months. Reduction in left ventricular mass was accompanied by an improvement in early diastolic filling pattern. This change in cardiac performance with cilazapril vasodilator monotherapy was characterized by a significant improvement in isovolumic relaxation time and normalized left ventricular early/atrial filling ratio.