Background Small-scale clinical investigations have demonstrated that single doses of beta -blocking agents can improve left ventricular function in heart failure from idiopathic dilated cardiomyopathy (IDC). The purpose of this multicenter clinical trial was to determine the dose-effect characteristics of beta -blockade in a heart failure population that includes ischemic dilated cardiomyopathy (ISCD).=5 units.Conclusions In heart failure from systolic dysfunction, beta -blockade with bucindolol produces a dose-related improvement in and prevents deterioration of left ventricular function. (Circulation. 1994;89:1632-1642.)