Increased Survival with Prophylactic Quinidine After Experimental Myocardial Infarction

Abstract

Experimental myocardial infarction was produced in 60 farm pigs by gradual coronary occlusion with an Ameroid constrictor placed around the left anterior descending coronary artery. Twenty animals were treated with 10 mg/kg/6 hr of quinidine, 10 with 5 mg/kg/6 hr, and 10 with 2.5 mg/kg/6 hr for a total period of 72 hours. Twenty animals served as controls. Serum quinidine levels were measured at 6-hour intervals. Significantly increased survival, when compared to controls, were observed in those animals treated with 5 and 10 mg/kg/6 hr of quinidine, but not in those receiving 2.5 mg/kg/6 hr. Under the described experimental conditions, designed to cause a reproducible, consistent infarction, quinidine treatment in nontoxic and well-tolerated doses significantly increased survival. Furthermore, there is a dose level below which this effect is lost. Whether the results of this study are applicable to man in preventing sudden death is unknown.