Dobutamine effects on blood gases and hemodynamics in acute myocardial infarction with heart failure.

We studied the effects of dobutamine on blood gases, venous admixture and hemodynamics in ten patients suffering an acute myocardial infarction (AMI) with left heart failure. After one hour infusion of dobutamine (mean dose: 6.3 micrograms/kg X min) there was an increase in cardiac index (27%, P less than 0.005), and a decrease in pulmonary wedge pressure (13%, P less than 0.025) and right atrial pressure (25%, P less than 0.025). The increase in oxygen delivery (23%, P less than 0.005) and mixed venous oxygen tension (10%, P less than 0.01) were neither accompanied by significant change in low arterial oxygen tension nor in high venous admixture. We conclude that dobutamine improves hemodynamics and oxygen delivery in AMI without affecting existant intrapulmonary shunting.