Atrial fibrillation (AF) has been treated with DC shocks delivered transthoracically, but in 5-30% of patients, the procedures fail to restore sinus rhythm (SR). We hypothesized that applying high energy shock waves to the chest may overcome the inadequate penetration of electrical
shock to the atrium. The aim of this study was to evaluate the efficacy of higher energy external DC
shock for the treatment of refractory AF coexisting with
cardiovascular disease using a synchronized double
external defibrillator. Fifteen patients (mean age 65 +/- 8) with refractory AF to standard DC
cardioversion (CV) underwent higher energy DC
shock using a double
external defibrillator. Concomitant
heart disease was present in all patients.
Warfarin and
amiodarone (600 mg/day), were administered for at least three weeks duration before DC CV. Sedation was performed with IV
midazolam. Two
defibrillator paddles were positioned on the anterior and posterior chest wall in a right lateral decubitus position.
Defibrillators were synchronized to the R waves and simultaneously 720 joules of energy was administered to the patients.
Amiodarone (200 mg/day) was continuously administered after DC
shock to maintain SR. Sinus rhythm was obtained in 13 patients. Sinus rhythm was persistent in 11 patients for six months duration.
Creatine kinase MB fractions were normal at 4 (22 +/- 4 IU/L) and 12 hours (18 +/- 4 IU/L). None of the patients developed significant hemodynamic compromise or
congestive heart failure, higher
AV block,
stroke, or transient ischemic cerebral events. The results indicate that higher energy DC
shock application using a double
external defibrillator is an effective and safe method for the
cardioversion of refractory AF. We believe this procedure should be performed before internal atrial
cardioversion.