Amelioration of heart failure by MDL 17043 and MDL 19205, novel positive inotropic drugs, in dog heart-lung preparations.

The efficacies of MDL 17043 and MDL 19205 in ameliorating heart failure were assessed in dog heart-lung preparations in which cardiac function had been severely depressed by pentobarbital. Six preparations were used for each drug. Both drugs in doses of 1-30 mumol similarly improved cardiac function in a dose-dependent manner and at 30 mumol improved it beyond control values. AV conduction impaired by pentobarbital was restored by 30 mumol of the 2 drugs. In these doses, however, neither of the drugs produced a significant increase in heart rate or arrhythmias. These results indicate that the 2 drugs would be of use in the treatment of heart failure.