Amrinone has been shown to exhibit a potent inotropic effect in patients with
heart failure secondary to
congestive cardiomyopathy, but its effects on myocardial oxygen consumption (MVO2) and coronary blood flow (CBF) are unknown. Accordingly, the hemodynamic, myocardial metabolic and ECG responses to
amrinone (2.5 mg/kg i.v. over 1 hour) were measured in nine patients with
congestive heart failure secondary to
coronary artery disease. Increases were observed in cardiac index (1.3 +/- 0.4 to 2.2 +/- 0.7 l/min/m2) and left ventricular
stroke work (10.6 +/- 3.0 to 19.2 +/- 6.3 g-m/m2), and decreases in mean pulmonary wedge (31 +/- 5 to 26 +/- 4 mm Hg), mean pulmonary artery (44 +/- 8 to 36 +/- 7 mm Hg) and mean right atrial pressures (18 +/- 4 to 10 +/- 4 mm Hg), myocardial arteriovenous
oxygen difference (129 +/- 19 to 109 +/- 17 ml/l), CBF (215 +/- 117 to 178 +/- 84 ml/min) and MVO2 (27 +/- 14 to 19 +/- 9 ml/min). All changes were significant (p less than 0.01). No significant changes occurred in aortic mean pressure, heart rate, myocardial
lactate extraction or ECG, and no patient developed angina. In explaining the decline in MVO2, it is possible that the increase in contractility was more than offset by the reductions in preload and afterload. The
amrinone-induced hemodynamic improvement in patients with
congestive heart failure secondary to
coronary artery disease was associated with reductions in MVO2 and CBF and no evidence of
myocardial ischemia.