Effects of i.v. prenalterol in patients with severe cardiac failure at rest and during exercise

Prenalterol administration (150 micrograms/kg i.v.) exerted beneficial effects on resting and/or exercise cardiac performance in patients with congestive cardiomyopathy (n = 12) and 1 patient with hypertensive heart disease (= group I, n = 13), while the haemodynamic response in patients with severe coronary heart disease (n=3) or cor pulmonale (n = 1) was non-uniform. At rest mean right and left ventricular filling pressures decreased by 26 and 19% (p less than 0.02 and p less than 0.02), respectively, while stroke volume increased by 8% (p less than 0.05), cardiac index by 25% (p less than 0.01) and heart rate by 15% (p less than 0.005) 5 min after prenalterol administration in group I. During exercise there was no further increase in heart rate, while filling pressures decreased and cardiac index increased significantly compared to control exercise. This typical inotropic response to prenalterol was observed in fully digitalised patients. Maximal effects occurred about 15 min after i.v. administration.