Comparative systemic and regional hemodynamic effects of dopamine and dobutamine in patients with cardiomyopathic heart failure.

Abstract

Patients with (13) severe cardiac failure underwent a single crossover study of dopamine and dobutamine in order to compare the systemic and regional hemodynamic effects of the 2 drugs. The dose-response data demonstrated that dobutamine (2.5-10 .mu.g/kg per min) progressively and predictably increases cardiac output by increasing stroke volume, while simultaneously decreasing systemic and pulmonary vascular resistance and pulmonary capillary wedge pressure. There was no change in heart rate (HR) or premature ventricular contractions (PVCs)/min at this dose range. Dopamine (2-8.mu.g/kg per min) increased the stroke volume and cardiac output at 4 .mu.g/kg per min. Dopamine at >4 .mu.g/kg per min provided little additional increase in cardiac output and increased the pulmonary wedge pressure and the number of PVCs/min. At >6 .mu.g/kg per min, dopamine increased HR. During the 24-h maintenance-dose infusion of each drug (dopamine 3.7-4, dobutamine 7.3-7.7 .mu.g/kg per min), only dobutamine maintained a significant increase of stroke volume, cardiac output, urine flow, urine Na concentration, creatinine clearance and peripheral blood flow. Renal and hepatic blood flow were not significantly altered by the maintenance dose of either drug. Systemic and regional hemodynamic data suggested that dobutamine has many advantages over dopamine when infused in patients with cardiac failure.