[Hemodynamic effects of dobutamine in patients with severe low-output heart failure (author's transl)].

We studied the hemodynamic effects of dobutamine in 10 patients with severe chronic heart failure due to congestive cardiomyopathy in 5, to ischemic heart disease in 4 and to hypertensive cardiomyopathy in 1. Dobutamine was injected during three periods of 30 min each alternated with equal periods of placebo at doses of 2,5-5 and 7,5 mcg/Kg/min respectively. The most favorable hemodynamic effects, obtained at an infusion rate of 5 mcg/Kg/min, was characterized by a significant inn 4 and to hypertensive cardiomyopathy in 1. Dobutamine was injected during three periods of 30 min each alternated with equal periods of placebo at doses of 2,5-5 and 7,5 mcg/Kg/min respectively. The most favorable hemodynamic effects, obtained at an infusion rate of 5 mcg/Kg/min, was characterized by a significant increase of the cardiac index and of the left ventricle stroke work index, accompanied by a significant decrease of the left ventricular filling pressure and of the systemic and pulmonary vascular resistance. The hemodynamic monitoring showed that the pharmacological effects of the drug subsided about 5-10 min after the interruption of infusion. At the infusion rate of 7,5 mcg/Kg/min we observed a significant increase of premature ventricular beats in 3 patients. We conclude that dobutamine at the dose of 5 mcg/Kg/min shows a powerfull positive inotropic action not accompanied by apparent side effects.