title: Utility of adjunctive single oral bolus propafenone therapy in patients with atrial defibrillators.
abstract: OBJECTIVE
  Previous studies have demonstrated that ambulatory atrial defibrillation shocks delivered by an implantable cardioverter-defibrillator (ICD) are safe and effective, but poorly tolerated. Separate studies have demonstrated the utility of single oral bolus propafenone for conversion of recent-onset atrial fibrillation (AF); however, most patients were hospitalized, had no structural heart disease, were taking no other antiarrhythmic drugs, and were not exposed to concomitant shock. We hypothesized that a single oral bolus dose of propafenone given early after onset would be a safe and effective adjunct to ICD-based AF therapy and improve overall therapy tolerance.
  
  
  RESULTS
  A randomized three-way crossover study design was used to compare three strategies, deployed in the ambulatory setting early after AF episode onset in 35 ICD patients with advanced, drug refractory episodic/persistent syndromes, many of whom had structural heart disease and were taking other antiarrhythmic drugs: (i) single oral bolus propafenone (600 mg), followed by ICD shock if necessary; (ii) single oral bolus placebo, followed by ICD shock if necessary; and (iii) no oral bolus therapy and ICD shock if necessary (no bolus). Antiarrhythmic efficacy, defined by the restoration of sinus rhythm within 24 h, was similar during propafenone (81%) and no-bolus strategies (84%); both were significantly higher than during placebo strategy (62%). Propafenone was well tolerated and not associated with proarrhythmia. Shock use was significantly lower during propafenone strategy (19%) than during no-bolus strategy (55%); this was correlated with improved patient tolerance.
  
  
  CONCLUSIONS
  Adjunctive use of single oral bolus propafenone is safe and effective in patients with an ICD and improves patient tolerance of device-based AF therapy.
authors.affiliation: University of Pittsburgh, UPMC Presbyterian, B535 Pittsburgh, PA 15213-2582, USA. schwartzmand@upmc.edu
authors.forename: David
authors.initials: D
authors.lastname: Schwartzman
authors.forename: Mark N
authors.initials: MN
authors.lastname: Harvey
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hoyt
authors.forename: Jodi L
authors.initials: JL
authors.lastname: Koehler
authors.forename: Michael R
authors.initials: MR
authors.lastname: Ujhelyi
authors.forename: David E
authors.initials: DE
authors.lastname: Euler
mesh_terms: D000284:Administration, Oral; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000628:therapy*; D003131:Combined Modality Therapy; D018592:Cross-Over Studies; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D011405:Propafenone / Q000008:administration & dosage*
chemical_list: D000889:Anti-Arrhythmia Agents; D011405:Propafenone