Lidocaine in the Prevention of Primary Ventricular Fibrillation

To assess the efficacy of lidocaine in preventing primary ventricular fibrillation in acute myocardial infarction a double-blind, randomized study was performed in 212 consecutive patients under the age of 70 years admitted to the hospital within six hours of infarction. Group A (107 patients) received an intravenous bolus injection of 100 mg of lidocaine followed by an infusion of lidocaine (3 mg per minute) for 48 hours. Group B (105 patients) received 5 per cent glucose and water. The groups were comparable in age, sex, site and size of infarction, admission time and mortality rate. Ventricular fibrillation did not occur in Group A but did in nine patients of Group B (p < 0.002). Side effects, including drowsiness, numbness, speech disturbances and dizziness, developed in 16 patients(15 percent). These findings indicate that lidocaine in the dosage given was highly effective in preventing primary ventricular fibrillation, but rigid observation of patients and control of infusion rates are required to decrease the likelihood of side effects. (N Engl J Med 291:1324–1326, 1974)