Hemodynamic effects of glucagon and intraaortic balloon counterpulsation in canine myocardial infarction

Abstract

The hemodynamic effects of glucagon (50 μg/kg) and intraaortic balloon counterpulsation were investigated in open chest anesthetized dogs after production of myocardial infarction and cardiogenic shock. Glucagon produced striking increases in arterial pressure, cardiac output and maximal left ventricular dp/dt together with a reduction in left ventricular end-diastolic pressure and systemic vascular resistance. The condition of most animals was stabilized at a viable level with 1 or more doses of glucagon. The effects of counterpulsation during severe cardiogenic shock were slight, although good counterpulsation was always achieved during control studies with normal pressure. When counterpulsation was instituted in combination with glucagon therapy there was an increase in mean arterial pressure together with a reduction in maximal left ventricular dp/dt and peak systolic pressure. Thus, counterpulsation tended to reduce the increased oxygen cost of the inotropic effects of glucagon. We suggest that an appropriate combination of counterpulsation and inotropic support (as with glucagon) may be better than either method alone.