Hemodynamic effects of oral ephedrine given alone or combined with nitroprusside infusion in patients with severe left ventricular failure

Abstract

Potent vasodilator or inotropic agents alone may be of limited value in some patients with severe congestive heart failure because of their exaggerated peripheral vascular effects. Nitroprusside and potent inotropic agents in combination are hemodynamically more effective than either alone. Although oral vasodilators can mimic nitroprusside, there is a need for potent oral inotropic agents. Ephedrine is an oral sympathomimetic inotropic drug. The hemodynamic effects of ephedrine alone (50 mg orally), nitroprusside alone and the two agents combined were studied in 11 patients with severe congestive heart failure. Heart rate increased from 89.9 ± 5.2 (standard error of the mean) to 98.2 ± 5.0 beats/min after ephedrine (P < 0.001) and to 96.4 ± 4.7 beats/min with ephedrine plus nitroprusside (P < 0.02); it was unchanged with nitroprusside alone. Mean systemic arterial pressure increased from 83.7 ± 2.1 to 89.2 ± 2.7 mm Hg after ephedrine (P < 0.02) and decreased to 73.4 ± 2.4 mm Hg with nitroprusside added (P < 0.01). Left ventricular filling pressure was unchanged after ephedrine but decreased from 30.9 ± 2.3 to 20.6 ± 2.1 mm Hg during nitroprusside infusion (P < 0.01). Control cardiac output averaged 3.94 ± 0.30 liters/min and increased by 1.25 ± 0.31 liters/min with nitroprusside, by 1.09 ± 0.30 liters/min after ephedrine and by 2.20 ± 0.34 liters/min with the two combined. Although the increases in cardiac output with each agent alone were significant and similar, the increase with the two combined was significantly greater than with either alone. The data suggest that ephedrine is an orally effective inotropic agent especially when combined with a vasodilator. Further evaluation of ephedrine in congestive heart failure is warranted.