The effect of intracoronary lidocaine infusion on acetylstrophanthidin-induced ventricular arrhythmia in dogs.

Antiarrhythmic drugs frequently cause extracardiac side effects that limit their use. If intracoronary delivery of a lower dose of drug to an electrically unstable focus can control arrhythmias, systemic adverse effects of these agents might be avoided. We investigated whether intracoronary lidocaine can suppress ventricular arrhythmia induced by acetylstrophanthidin, a rapidly acting digitalislike agent. We isolated and then cannulated either the left anterior descending or the left circumflex coronary artery in 12 pentobarbital-anesthetized dogs. Sustained ventricular tachycardia that persisted for 11.4 +/- 8.6 minutes was reliably induced by the intracoronary infusion. In all of 24 trials, an intracoronary lidocaine bolus at 2% of the usual systemic dose (0.77 mg/30 sec) abolished digitalis-induced ventricular tachycardia for an average of 2.0 +/- 1.8 minutes. This effect was not observed after a saline bolus. We conclude that an intracoronary bolus of low-dose lidocaine can suppress acetylstrophanthidin-induced ventricular arrhythmia.