Vasodilator therapy for chronic left ventricular failure.

The effects of chronic oral vasodilator therapy were studied in a group of patients with refractory congestive heart failure. Fifteen patients were treated acutely with intravenous sodium nitroprusside and sublingual isosorbide dinitrate. After continuous therapy with nitroprusside and isosorbide dinitrate for up to 72 hours the patients were then placed on isosorbide dinitrate and oral phenoxybenzamine. Hemodynamic responses to nitroprusside, isosorbide dinitrate, and phenoxybenzamine with isosorbide dinitrate were determined. After a mean follow-up of seven months, nine patients who were receiving isosorbide dinitrate and phenoxybenzamine underwent repeat hemodynamic studies. Beneficial effects of acute vasodilator therapy included a significant reduction in pulmonary capillary wedge pressure and systemic vascular resistance, and significant increases in cardiac index and stroke work index. Mean arterial blood pressure and heart rate were unchanged. During the period of chronic vasodilator administration, no other change in basic therapy with isosorbide dinitrate and phenoxybenzamine (3-21 months), the favorable effects observed acutely were maintained. All patients demonstrated symptomatic improvement with minimal side effects. The beneficial hemodynamic responses that are noted with acute vasodilator therapy in patients in advanced congestive heart failure are maintained with oral therapy on a chronic basis.