Despite considerable interest in the use of β-blocking agents in congestive heart failure (CHF), their clinical application is limited because of their negative inotropic effects. Beta blockers with vasodilating properties may have the advantage of overcoming this, however. Carvedilol, a β-blocking agent with vasodilating properties, was evaluated in 17 patients with chronic CHF secondary to ischemic heart disease with a resting left ventricular ejection fraction ≤45%, who were being maintained on diuretics. Exercise testing, radionuclide ventriculography, and right-sided cardiac catheterization were performed and intraarterial blood pressure measured before and after 8 weeks of carvedilol therapy in a dosage of 12.5 to 50.0 mg twice a day. Twelve patients completed the study and 5 withdrew. Symptomatic and hemodynamic improvement was demonstrated in 11 of the 12 patients. Heart rate and intraarterial blood pressure were both reduced by chronic therapy. Mean ± standard deviation exercise time improved from 4.3 ± 1.6 to 7.1 ± 2.7 minutes (p < 0.0001), as did resting left ventricular ejection fraction, from 27 ± 9 to 31 ± 11% (p < 0.02). Pulmonary arterial wedge pressure fell from 19 ± 7 mm Hg to 12 ± 5 mm Hg (p < 0.001) and total systemic vascular resistance from 1,752 ± 403 to 1,497 ± 310 dynes/ s/cm-5/m2 (p < 0.02). Stroke volume index improved also, from 31 ± 6 ml to 40 ± 6 ml (p < 0.0005). These hemodynamic changes were mediated partly by vasodilatation, diminished myocardial oxygen demand and reduction of sympathetic overactivity in the failing heart. These data suggest that carvedilol may have beneficial effects in patients with chronic CHF secondary to coronary artery disease. © 1990.