Effect of parenteral d-sotalol on transvenous atrial defibrillation threshold in a canine model of atrial fibrillation.
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.
Iskos
D
D
Cardiac Arrythmia Center, Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
Lurie
K G
KG
Adler
S W
SW
Shultz
J J
JJ
Coffeen
P R
PR
Mulligan
K A
KA
Benditt
D G
DG
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*
D000889:Anti-Arrhythmia Agents; D013015:Sotalol