Combined therapy with dobutamine and amrinone in severe heart failure. Improved hemodynamics and increased activation of the renin-angiotensin system with combined intravenous therapy.

The hemodynamic and hormonal responses to dobutamine alone and with the addition of amrinone were studied in ten patients with severe heart failure. Dobutamine significantly increased heart rate, cardiac index, and stroke volume index and significantly decreased mean right atrial and systemic arterial pressures and systemic and pulmonary vascular resistance. The addition of amrinone further decreased significantly mean right atrial, pulmonary arterial, and pulmonary arterial wedge pressures and systemic vascular resistance, while heart rate rose. The response of the cardiac index was variable, increasing in seven and decreasing in three patients. Plasma renin activity rose significantly with dobutamine and further increased with amrinone. We conclude that in most patients with severe heart failure, amrinone, when combined with dobutamine, improves hemodynamics. The further increase in heart rate, variable effects on the cardiac index, and marked activation of the renin-angiotensin system suggest caution and potential limitations in the use of this combination.