[Intramuscular injection of lidocaine in prevention of complications and mortality in acute myocardial infarction: double blind study on 246 cases (author's transl)].

246 cases of acute myocardial infarction in subjects aged 70 or less, with clinical symptoms beginning no more than 8 hours before, altered enzymes, abnormal Q wave, ST segment and T wave, were studied. 99 of them received, on hospital admission, an intramuscular injection of 250 mg of lidocaine, 147 an injection of saline. In the following 3 weeks, significant differences were observed in the appearance of severe arrhythmias (no cases in the treated group and 18 cases in the placebo group, p less than 0,001) and of heart failure (39 cases in the treated group and 79 in the placebo group, p less than 0,05) and in mortality (3 cases in the treated group and 18 in the placebo group, p less than 0,05).