Hemodynamic studies in cardiogenic shock. Treatment with isoproterenol and metaraminol.

In 14 subiects with severe cardiogenic shock the characteristic findings before treatment were hypotension, low cardiac output, and increased central venous pressure, with normal values for total peripheral resistance. Oliguria, lactic acidosis, hypocapnia. and hypoxemia also were present. These changes were interpreted as reflecting acute heart failure in association with a peripheral vascular response which was inadequate to maintain normal blood pressure. Isoproterenol caused a decrease in venous pressure and an increase in cardiac output. In most cases this was sufficient to increase blood pressure, despite slight reductions in peripheral vascular resistance. In a few cases, however, the inotropic effect of the drug was so small that the reduction in vascular resistance caused a further fall in arterial pressure. Metaraminol caused elevation of