Toxic effects of lignocaine on the circulation.

Abstract

There is little doubt concerning the efficacy of lignocaine (Xylo caine) in the treatment of many cardiac arrhythmias, parti cularly during cardiac catheterization (Southworth et al., 1950), during intubation and induction of anaesthesia and cardiac surgery (Weiss, 1960), and after myocardial infarction (Lown et al., 1967; Jewitt et al., 1968; Spracklen et al., 1968). In spite of the apparent value of the drug there is little information on its haemodynamic effects, and this communication is con cerned with evaluating its effect in small doses in man and much larger doses in dogs. This investigation was done to determine whether a continuous infusion of lignocaine could be used in all patients after myocardial infarction to suppress the common ventricular ectopic beats, and possibly act as a prophylactic measure to prevent arrhythmias causing further myocardial deterioration. Lown et al. (1967) expressed the opinion that antiarrhythmic drugs might jeopardize survival after myocardial infarction by reducing myocardial contractile force.