Independent and interactive effects of digoxin and quinidine on the atrial fibrillation threshold in dogs
Journal of the American College of Cardiology
To assess the effects of digoxin as single therapy and in combination with quinidine in the treatment of atrial fibrillation, the atrial fibrillation threshold was determined from the right atrial appendage and Bachmann's bundle in 11 open chest dogs. In group 1 (six dogs), the atrial fibrillation threshold was determined at baseline, post-quinidine (10 mg/kg intravenously) and then post-digoxin (50 µg/kg intravenously). In group 2 (five dogs), the order of drug administration was reversed. The results of this study were: 1) Digoxin had no significant effect on the atrial fibrillation threshold when given alone. 2) Quinidine significantly increased the atrial fibrillation threshold (p < 0.002) and the addition of digoxin resulted in a further increase in threshold (p < 0.002). 3) Quinidine produced greater suppression of atrial fibrillation induction at the right atrial site than at the Bachmann's bundle site, suggesting differential effects of quinidine on atrial fibers. © 1985, American College of Cardiology Foundation. All rights reserved.
Gold, R., Bren, G., Katz, R., Varghese, P., & Ross, A. (1985). Independent and interactive effects of digoxin and quinidine on the atrial fibrillation threshold in dogs. Journal of the American College of Cardiology, 6 (1). http://dx.doi.org/10.1016/S0735-1097(85)80262-X