Improvement of cardiac performance by pimobendan, a new cardiotonic drug, in the experimental failing dog heart.

The cardiotonic effect of pimobendan was studied in 6 dog heart-lung preparations in which cardiac function had been severely depressed by pentobarbital. Pimobendan in doses of 1-10 mg improved cardiac function in a dose-dependent manner and at 10 mg improved it beyond the control. These doses of pimobendan, however, produced neither a significant increase in heart rate nor arrhythmias. The results indicate that the drug may be of use in the treatment of heart failure.