Intravenous fenoldopam infusion in severe heart failure.

Fenoldopam, a selective DA1-receptor agonist, infused intravenously for 24 hours (0.6 +/- 0.3 microgram/kg/min, range 0.1-1.5) in 25 patients with NYHA functional class III or IV heart failure, produced a prompt and sustained hemodynamic response. Cardiac index rose from an average preinfusion baseline value of 1.8 to 2.6/l min. Stroke volume index increased from 19 to 26 ml/m2 and stroke work index increased from 18 to 25 g M/m2. These changes were accompanied by a reduction in systemic vascular resistance from an average of 2400 to 1500 dynes sec/cm5. There was no change in the heart rate or right atrial pressure. There was a transient reduction in the left ventricular filling pressure from 25 to 20 mmHg. Urinary sodium excretion did not change significantly. Transient asymptomatic thrombocytopenia developed in four patients. The drug was well tolerated by all patients. These results suggest that continuous intravenous infusion of fenoldopam is safe and produces favorable hemodynamic responses in severe heart failure. However, unlike its effects in patients with hypertension, it failed to produce sustained natriuresis in these patients.