The hemodynamic changes after anti-hypertension therapy were studied by impedance cardiography in 86 patients with essential hypertension. 49 normal subjects were included in this study as a contral group. A increased total peripheral resistance (TPR)

decreased strok valume (SV) cardiac output (CO) and cardiac index (CI) were noted in hypertension

but systolic time interval (STI)was unchanged. The incidence of abrormal pattern of impedance cardiognam (the abrqrmal rate of dZ/dT) in the paetients group was 58%. Hewever there was 14% in the normal subjects only.It was shown that hydrochlorothiazide and nifedipine causing a reduction in blood pressure and benefit in hemodynamic parameters were more effective than propranolol aad captopril