Abstract

To evaluate the hemodynamic effect of prazosin in patients of chronic refratory heart failure, echocardiographic measurement of left ventricular performances was performed in 14 patients acute hemodynamic effects were evaluated around 90 minutes after the administration of prazosin(6mg) orally (Group A, 7 patients) and the chronic hemodynamic effects were evaluated after 7 days with prazosin treatment 24mg daily in four divided doses(Group B, 11 patients). End-systolic dimension of left ventricle was decreased significantly but the end-diastolic dimension was not 90 minutes after treatment. Both endsystolic and end-distolic dimensions were decreased with significance after a week of treatment. The stroke volume was increased in both groups, heart rate decreased in group B only, but neither ventricular ejection time nor cardiac output was significantly changed with praozsin treatment, Ejection fraction, fractional shortening mean rate of cirumferentia1 fiber shortening and stroke work were increased effectively after prazosin the rapy in both groups. Total peripheral resistance was measurably decreased #on#ly in group B. All but one of the study group were clinically improved usually from NYHA functional classes Ⅳ or Ⅲ to Ⅲ or Ⅱ. In so far as it concern with 5 patient, with whom we could followed linically over a 2 to 8 months' period, no discernible, tolerance to the drug was observed,