title: Effect of parenteral d-sotalol on transvenous atrial defibrillation threshold in a canine model of atrial fibrillation.
abstract: In an effort to reduce energy requirements for atrial defibrillation to a level low enough to perform painless electrical cardioversion with an implantable atrial defibrillator, we tested the hypothesis that drug therapy with the class III agent d-sotalol, when used concurrently with a low-energy shock, reduces atrial defibrillation threshold. In a nonthoracotomy canine model of atrial fibrillation, intracardiac shocks were delivered between the distal coronary sinus and the mid-right atrium. Based on a step-up energy delivery protocol the atrial defibrillation threshold was defined as the least amount of energy that resulted in a >10% and <90% rate of successful defibrillation. At a dose associated with class III antiarrhythmic effects (5 mg/kg), d-sotalol significantly reduced atrial defibrillation threshold from 1.72 +/- 1.12 J to 0.59 +/- 0.60 J (p < 0.01). These results support the feasibility of using antiarrhythmic drug therapy with d-sotalol to minimize energy requirements for intracardiac electrical cardioversion of atrial fibrillation.
authors.affiliation: Cardiac Arrythmia Center, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
authors.forename: D
authors.initials: D
authors.lastname: Iskos
authors.forename: K G
authors.initials: KG
authors.lastname: Lurie
authors.forename: S W
authors.initials: SW
authors.lastname: Adler
authors.forename: J J
authors.initials: JJ
authors.lastname: Shultz
authors.forename: P R
authors.initials: PR
authors.lastname: Coffeen
authors.forename: K A
authors.initials: KA
authors.lastname: Mulligan
authors.forename: D G
authors.initials: DG
authors.lastname: Benditt
mesh_terms: D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D001283:Atrioventricular Node / Q000187:drug effects / Q000503:physiopathology; D003331:Coronary Vessels / Q000187:drug effects / Q000503:physiopathology; D017147:Defibrillators, Implantable; D004195:Disease Models, Animal; D004285:Dogs; D004554:Electric Countershock / Q000379:methods*; D017097:Electric Impedance; D005240:Feasibility Studies; D006325:Heart Atria / Q000187:drug effects / Q000503:physiopathology; D007263:Infusions, Parenteral; D007536:Isomerism; D012032:Refractory Period, Electrophysiological / Q000187:drug effects; D013015:Sotalol / Q000627:therapeutic use*
chemical_list: D000889:Anti-Arrhythmia Agents; D013015:Sotalol