[Effect of Chinese-made vesnarinone on experimental heart failure of dog].

Intravenous drip of sodium pentobarbital 6 mg/kg per min induced obvious heart failure of anesthetic dogs (n = 11) followed by an infusion of 0.25 mg/kg per min to maintain the heart failure state. The Chinese-made vesnarinone 3 mg/kg was injected, followed by an infusion of 0.1 mg/kg per min, or the solvent in the same volume, for 30 min. Vesnarinone increased significantly and instantly the cardiac output and left ventricular maximum + dp/dt, which almost recovered to normal at the end of the infusion and also significantly increased 30 min after administration. The positive inotropic effect of vesnarinone was not accompanied by an increase in the heart rate and the blood pressure. The results of our experiment reveal that the Chinese-made vesnarinone has a potent and relatively selective positive action on heart failure of dogs.