Serial hemodynamic studies during the treatment of congestive heart failure with isolated low-dose oral prazosin therapy.

Prazosin was administered orally at a maximal dose of 2 mg every 6 hours to 4 patients with congestive heart failure (CHF) who had not received either digitalis or diuretics for 72 hours before therapy. Three of the 4 patients had hypertensive and arteriosclerotic heart disease. Hemodynamic monitoring indicated a significant reduction of preload and afterload with a concomitant rise in the cardiac index. We concluded that isolated low-dose oral prazosin has salutary effects on indices of hemodynamic function in selected patients.