EFFECTS OF ARTILIDE ON SPONTANEOUS AND INDUCED VENTRICULAR ARRHYTHMIAS IN 24-HOUR CANINE MYOCARDIAL-INFARCTION

The electrophysiologic and antiarrhythmic effects of artilide were eva luated in dogs 24 h after myocardial infarction. Artilide (0.1 to 3.0 mg/kg or 0.2 to 7.0 mu M/kg iv) prevented programmed stimulation induc ed ventricular arrhythmias in 9 out of 9 dogs that had demonstrated in ducible ventricular arrhythmias prior to treatment. This antiarrhythmi c action was associated with significant increases in ventricular refr actoriness and monophasic action potential duration. Lower doses of ar tilide tended to reduce the incidence of spontaneous ventricular arrhy thmias but these effects were not significant. These results are consi stent with the concept that spontaneous and pacing induced ventricular arrhythmias result from different mechanisms, and that class III anti arrhythmic agents are more effective in suppressing induced ventricula r tachycardia due to reentry than spontaneous arrhythmias which result from nonreentrant mechanisms. (C) 1993 Wiley-Liss, Inc.