Cardiovascular Effects of Glucagon in Man

Because glucagon in animals has positive inotropic and chronotropic effects in the presence of beta-adrenergic blockade, catecholamine depletion or full digitalization, its cardiovascular effects in man were studied during diagnostic cardiac catheterization. In 11 patients 3 to 5 mg intravenously significantly increased cardiac index, mean arterial pressure, heart rate and maximum rate of left ventricular pressure development, but left ventricular end-diastolic pressure and systemic vascular resistance did not change significantly. Action after a single dose began in one to three, reached a maximum in five to seven and lasted for 10 to 15 minutes. In six patients given only 1 mg the only significant changes were increased cardiac index and decreased systemic vascular resistance. Glucagon benefits cardiac performance in man, and with its demonstrated action in the absence of catecholamines and in the presence of full digitalization, may be useful to treat acute heart failure.