Haemodynamic effects of prenaterol and cardiac glycosides in patients with recent myocardial infarction.

Prenalterol was given to twenty five patients with acute myocardial infarction. Thirteen patients (group B) had signs of cardiac decompensation while twelve (group A) had not. Ejection fraction was determined with 99mTc-labelled red blood cells before and after prenalterol (50 micrograms kg-1 body weight), intravenously. In group B this procedure was repeated after digitalization 2 days later. The ejection fraction increased significantly in group A after prenalterol injection. In group B, prenalterol produced an increase, but this was not significant. After digitalis the ejection fraction increased significantly and prenalterol produced an additional significant rise. No significant changes in blood pressure occurred. Heart rate increased significantly in both groups after prenalterol injection and decreased significantly after digitalis.