title: Effect of sotalol, aprindine and the combination aprindine-sotalol on monophasic action potential duration.
abstract: The effects of sotalol, aprindine and the combination aprindine-sotalol in the intact dog heart were evaluated during constant atrial pacing with the use of monophasic action potential (MAP) recording. A first group of five dogs was given 1.5 mg kg-1 body weight of sotalol, followed by a second infusion of 1.5 mg kg-1 30 min later. Both doses of sotalol produced a statistically significant increase in right atrial MAP duration at 50% of repolarization (RAMAP50) and right ventricular MAP duration at 90% of repolarization (RVMAP90). To a second group of six dogs aprindine 1 mg kg-1 and aprindine 2 mg kg-1 were administered intravenously. The infusion of aprindine did not alter right atrial and right ventricular MAP duration. The addition of 1.5 mg kg-1 of sotalol to the dogs pretreated with aprindine 2 mg kg-1 resulted in a 25% increase in RAMAP50 and a 21% prolongation of RVMAP90. In summary, sotalol lengthens atrial and ventricular monophasic action potential duration and still prolongs repolarization of monophasic action potentials after previous administration of aprindine. A combination of sotalol, a beta-adrenergic blocker possessing class III efficacy, with a class I antiarrhythmic agent may be useful with respect to their electro-physiological action.
mesh_terms: D000818:Animals; D001073:Aprindine / Q000494:pharmacology*; D002304:Cardiac Pacing, Artificial; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004562:Electrocardiography; D006325:Heart Atria / Q000187:drug effects; D006329:Heart Conduction System / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects; D007192:Indenes / Q000494:pharmacology*; D007263:Infusions, Parenteral; D013015:Sotalol / Q000494:pharmacology*
chemical_list: D007192:Indenes; D001073:Aprindine; D013015:Sotalol