Effects of ionic salts or acetylcholine, or both, on electrically induced ventricular fibrillation in dogs

A dose-response curve was delineated for an acetylcholine-potassium chloride cocktail previously found to be highly effective in chemically defibrillating electrical induced ventricular fibrillation of thoracotomized dogs. The cocktail dosage responsible for the greatest percentage of chemical defibrillations was transthoracically given to nonthoracotomized dogs subjected to ventricular fibrillation; this resulted in 33% chemical defibrillation. Two clinical canine patients were transthoracically administered the acetylcholine-potassium chloride cocktail because they failed to respond to external electrical defibrillation; both were chemically defibrillated. Potassium citrate when substituted for potassium chloride, in the cocktail, or alone appeared to be more efficacious for chemical defibrillation. Magnesium chloride with acetylcholine failed to chemically defibrillate any dog administered this cocktail.