N-acetylprocainamide and ischemia-induced ventricular fibrillation in the dog.

Open-chest dogs anesthetized with pentobarbital were treated with saline or N-acetylprocainamide (20 mg/kg, i.v.) 10 min prior to simultaneous ligation of the left anterior descending and septal coronary arteries. Ventricular fibrillation occurred in 20 of 26 control dogs but in only 6 of 15 dogs treated with N-acetylprocainamide (P less than 0.05). Since N-acetylprocainamide significantly reduced spontaneous heart rate this may have contributed to its antifibrillatory effect.