Lidocaine in the Prevention of Sudden Death in the Pre-Hospital Phase of Acute Infarction

A double-blind study was undertaken to test the hypothesis that a prophylactic injection of 300 mg of lidocaine as a 10 per cent solution into the deltoid muscle would prevent death for two hours after injection during the pre-hospital phase of acute myocardial infarction. Two hundred and thirty-three Australian family physicians randomly administered lidocaine or placebo to their patients at the earliest suspicion of acute infarction. Patients over 70 years, with heart rate <56 beats per minute, systolic arterial pressure <91 mm Hg, or more than 12 hours of symptoms were excluded from the study. A total of 269 patients with either definite or possible infarction satisfied the criteria of the protocol. During the first two hours after injection three out of 156 lidocaine-treated and eight out of 113 placebo-treated patients died (p<0.03). Early prophylactic administration of lidocaine may decrease mortality during the pre-hospital phase of acute myocardial infarction. (N Engl J Med 291:1327–1331, 1974)