The hemodynamic and metabolic advantages gained by a three-day infusion of dobutamine in patients with congestive cardiomyopathy.

Most patients with nonischemic congestive cardiomyopathy (COCM) derive subjective benefit from a 3-day intravenous infusion of dobutamine. The mechanism of this improvement was evaluated by the measurement of metabolic factors (serum sodium and blood urea nitrogen [BUN]) during the infusion in 23 group I patients. In addition, six patients (group II) had an endomyocardial biopsy procedure before and after 3 days of bed rest and then after 3 days of dobutamine. The tissue was analyzed for adenosine triphosphate (ATP) and creatine. The eight group III patients had cardiac output, coronary sinus blood flow, and arterial and coronary sinus oxygen saturation measurements before and during two dose increments of dobutamine (5 and 10 micrograms/kg/min). The results demonstrated that the mean sodium of group I patients rose from 135 +/- 3 (means +/- SD) to 137 +/- 4 mEq/L (p less than 0.05) and the BUN fell from 21 +/- 7 to 15 +/- 6 mg/100 ml (p less than 0.001). The ATP/creatine of the endomyocardial biopsies from group II did not change from control with bed rest (0.36 +/- 0.24 to 0.37 +/- 0.24), but rose to 0.62 +/- 0.26 (p less than 0.05) after dobutamine. In group III, the cardiac output and coronary blood flow increased proportionately with increasing doses of dobutamine. These data suggest that there are both metabolic and hemodynamic advantages gained during a 3-day infusion of dobutamine, and that either or both could contribute to the clinical improvement noted in patients with COCM.