[Acute hemodynamic effects of pimobendan and captopril: a comparative study in the same patients with chronic heart failure].

In this study, the acute hemodynamic effects of pimobendan (2.5 mg), a new drug, was compared with that of captopril (12.5 mg) in the same 8 patients with chronic heart failure (NYHA class II-III); 3 with dilated cardiomyopathy and 5 with regurgitant valvular heart disease. The hemodynamics were serially assessed before and after drug administration for at most 6 hours. Pimobendan reduced mean blood pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, right atrial pressure, total systemic vascular resistance, and total pulmonary vascular resistance but it increased heart rate. By contrast, captopril reduced mean blood pressure and double product. No significant changes were noted in the cardiac index, stroke volume index, AV-O2 difference or the arterial oxygen pressure between the 2 drugs. In conclusion, pimobendan seems to function as a strong arterio-veno-dilator rather than as an inotropic agent in patients with chronic heart failure.