A prospective randomized trial of tocainide in patients following myocardial infarction

One hundred forty-six patients with recent acute myocardial infarction were grouped at random into those treated with tocainide, an oral analogue of lignocaine, or placebo and followed up for 6 months. In addition to standard investigations, a 24-hour ambulatory taped ECG recording was obtained prior to randomization and thereafter at 2, 8, 16, and 24 hours after discharge. The ECGs were analyzed by means of an automated, computerized reporting system. Forty-two patients had significant ventricular arrhythmias, 10 of whom had effective plasma levels of tocainide compared with 27 patients on placebo (P < 0.005). In the placebo patients with increasing mobilization there was a consistent rise in the number of ventricular ectopic beats per day. There was no such increase in the tocainide patients (P < 0.01). Side effects were few and the incidence of central nervous system side effects was similar in both the tocainide and placebo groups. There was no conclusive evidence of myocardial depression, heart rate and blood pressure being unchanged over the 6-month period. Although ventricular arrhythmias were suppressed, the number of patients in the study was too small to draw conclusions regarding the mortality rate.