Control of lidocaine therapy: new perspectives.

Although lidocaine has been available for clinical use for 30 years, it still retains an important place amongst antiarrhythmic drugs. It is still widely regarded as the first line of therapy in ventricular arrhythmias occurring after myocardial infarction or cardiac surgery. Recently, however, its use has been advocated in the prophylaxis of primary ventricular fibrillation occurring after myocardial infarction. This recommendation is based primarily on the well-designed and controlled study of Lie and co-workers (1). The results of this study have been reviewed and compared with the results of 11 other studies showing no significant effect of lidocaine in this situation (2). One other study did show that lidocaine gave protection against primary ventricular fibrillation (3). The authors concluded, however, that all the other studies had major defects in trial design, and were prepared to accept the conclusion that lidocaine was effective in preventing primary ventricular fibrillation after myocardial infraction. Similar conclusions were made by De Silva and co-workers (4). As a result, the drug is given in several centres in the U.S.A. to patients admitted with suspected acute myocardial infarction, particularly those aged less than 70 years who are seen within 6 h of the onset of chest pain (5,6).