Hemodynamic and regional blood flow response to milrinone in patients with severe congestive heart failure: A dose-ranging study

This study was undertaken to assess the hemodynamic efficacy, changes in regional blood flow, and safety of milrinone over a range of intravenous bolus injections (12.5 to 125 μg/kg), a continuous 18-hour infusion (0.2 to 0.7 μg/kg/min), and following oral administration. All eighteen patients with New York Heart Association class III or IV congestive heart failure demonstrated hemodynamic improvement following intravenous bolus therapy. Dose-related increases in cardiac index occurred, ranging from a 12 ± 6% increase following a 12.5 μg/kg bolus to a 37 ± 10% increase after 75 μg/kg. Pulmonary wedge pressure fell 17 ± 5% following 12.5 μg/kg and 28 ± 9% following 75 μg/kg. Little change was apparent during the continuous infusion except for a late increase in cardiac index, but similar changes occurred in response to a single oral dose. Forearm blood flow increased significantly after 3 hours in the two higher infusion groups, but there was no consistent change in hepatic blood flow. We conclude that hemodynamic parameters and forearm blood flow are improved in patients with severe congestive heart failure following intravenous and short-term oral milrinone therapy.