Oral hydralazine therapy for chronic refractory heart failure.

The hemodynamic effects of oral hydralazine were investigated in ten patients (nine in NYHA Class IV and one in Class III) with chronic refractory heart failure. With hemodynamic monitoring, adequate oral doses of hydralazine (50 or 75 mg) were determined and then administered every six hours. Hemodynamics were determined at 2-3, 6-8 and 24 hours on hydralazine therapy. Arterial pressure decreased slightly (5%) and systemic vascular resistance decreased significantly (42%). Cardiac and stroke volume index increased by 70 and 66%, respectively, without any significant change in heart rate, pulmonary capillary wedge or right atrial pressure. Hemodynamic improvement was associated with clinical improvement without a major complication. During the follow-up period of 3-7 months, seven of nine patients were in NYHA Class II and one in Class III. One other patient died suddenly six weeks after discharge. These findings suggest that hydralazine in an effective oral vasodilator for the treatment of refractory heart failure.