The phosphodiesterase inhibitor enoximone has both vasodilating and positive inotropic pharmacological properties. The balance between vasodilation and positive inotropism may be different between the various types of heart failure as well as the various stages of heart failure. Therefore, we investigated the effect of intravenous application of enoximone (1 mg/kg body weight) in a cohort of patients (n = 10) suffering from acute or subacute heart failure mainly due to ischemia or hypoxia. All patients had high left ventricular filling pressure, low cardiac output and were pretreated with intravenous dobutamine. Enoximone increased cardiac output from 3.2 +/- 1.2 to 5.5 +/- 2.2 l/min, increased heart rate from 94 +/- 20 to 100 +/- 18 beats/min, decreased systemic peripheral resistance from 1770 +/- 861 to 931 +/- 340 dyn.sec.cm-5 and decreased pulmonary wedge pressure from 24 +/- 5 to 20 +/- 6 mmHg, significantly. However, systolic aortic pressure, systolic pulmonary pressure and right atrial pressure were not significantly altered. We conclude that in a selected group of patients enoximone-given intravenously and acutely in the intensive care unity-can induce beneficial effects on central hemodynamics without critical falls in perfusion pressure.