Effects of Certain Local Anesthetic Drugs Upon Ventricular Tachycardia Resulting From Myocardial Infarction

Abstract

Tests of the ectopic suppressor effectiveness of 5 local anesthetic agents, and of toxic manifestations induced by them, were performed in dogs with ventricular tachycardia associated with myocardial infarction. The agents tested were tetracaine (Pontocaine), Panthesine, lidocaine (Xylocaine), hexylcaine (Cyclaine) and piperocaine (Metycaine). All proved to be capable of reducing or abolishing ectopic activity for certain periods of time if used in adequate amounts and at sufficient rates of infusion. Convulsive movements and vomiting resulted from ectopic suppressor dosage with tetracaine, Cyclaine and lidocaine even with phenobarbital sedation. Panthesine was less toxic, but produced some head tremors when used alone. The duration of antiarrhythmic action of Panthesine was brief after infusion was stopped. In the one dog tested with piperocaine, the drug first reduced the ectopic frequency and then increased it beyond the control level. This pattern of response was previously found unfavorable.