Improvement of Pentobarbital-Induced Heart Failure by MCI-154, a Novel and Potent Cardiotonic Agent, in the Dog Heart-Lung Preparation

Abstract

The efficacy of MCI-154, a new pyridazinone cardiotonic agent, in improving heart failure was assessed in dog heart-lung preparations in which cardiac function had been severely depressed by pentobarbital. MCI-154 in doses of 10-100 μig improved the cardiac function curve and restored it to the control level at 100 μg. At this dose, MCI-154 neither produced an increase in heart rate beyond the control value nor induced arrhythmias. The effects of MCI-154 were not affected by atenolol, a cardioselective β₁-blocker. These results indicate that MCI-154 would be of potential use in the treatment of heart failure.