Combined nitroprusside-dopamine therapy in severe chronic congestive heart failure. Dose-related hemodynamic advantages over single drug infusions

To assess the circulatory effects of afterload reduction and inotropism individually and in combination as rational therapy for refractory heart failure, nitroprusside and dopamine were administered to 13 patients with severe cardiac decompensation. Dopamine at average doses of 3 and 7 microgram/kg per min produced increases in cardiac output and reductions in peripheral resistance. At doses of 15 microgram/kg per min, dopamine increased heart rate, peripheral arterial pressure and side effects. Nitroprusside alone decreased left-sided filling pressures and increased cardiac output. When the agents were administered together, the increases in cardiac output were significantly greater than with either agent alone and there was physiologic improvement in overall circulatory function. The relations among changes in afterload (systemic impedence), preload (filling pressures) and cardiac index help to explain the salutary effects of combined therapy in patients with refractory heart failure.