Effects of the novel beta-adrenergic partial agonist alifedrine on cardiac performance in dogs with acute ischemic left ventricular failure.

Acute ischemic left ventricular failure was induced in dogs by coronary embolization with plastic microspheres, resulting in reduced cardiac output (CO), increased left ventricular end-diastolic pressure (LVEDP), pulmonary capillary pressure (PCP), and total peripheral resistance (TPR). Intravenous (i.v.) administration of alifedrine, a beta-adrenergic partial agonist (0.3 mg/kg as bolus and 0.3 mg/kg/h as infusion), significantly improved performance of the failing heart. Left ventricular contractility was increased up to 50%, heart rate (HR) up to 28%, and CO up to 30%. LVEDP, PCP, and TPR were markedly decreased. Myocardial oxygen consumption was increased only to a minor degree despite the positive inotropic effect; coronary flow was augmented up to 26%. Thus, alifedrine in this model markedly improved left ventricular function by balanced stimulation of the myocardium and reduction of pre- and afterload.