title: Early recurrence of atrial fibrillation after ambulatory shock conversion.
abstract: OBJECTIVE
  We sought to gain insights into the early recurrence of atrial fibrillation (ERAF) after cardioversion shocks delivered by permanently implanted rhythm management systems.
  
  
  BACKGROUND
  Several reports have characterized ERAF, but these reports used a limited definition and did not evaluate an association between clinical or device variables and ERAF.
  
  
  METHODS
  A total of 144 patients with recurrent, drug-resistant, symptomatic atrial fibrillation (AF) underwent implantation of an atrial rhythm management system (Medtronic Jewel AF, Model 7250, Minneapolis, Minnesota). The device was programmed to deliver cardioversion shocks automatically and/or on patient command. The incidence of ERAF was evaluated after 1,092 successful shocks among 97 patients. Three different ERAF definitions were used: recurrence within 1 min, 1 h or 1 day. Multiple clinical and device variables were assessed for their relationship with ERAF.
  
  
  RESULTS
  The per-patient incidences of ERAF were 44%, 61% and 70% for ERAF within 1 min, 1 h and 1 day, respectively. The per-episode incidences of ERAF were 17%, 30% and 43% for ERAF within 1 min, 1 h and 1 day, respectively. Variables that were independently associated with ERAF included AF duration <3 h before termination, more than one shock required to cardiovert and the absence of a previous myocardial infarction. The most potent variable was AF duration <3 h, associated with a threefold increase in the incidence of ERAF.
  
  
  CONCLUSIONS
  Recurrence of AF early after ambulatory shock cardioversion is common. In this retrospective study, both clinical and device variables were predictive.
authors.affiliation: Atrial Arrhythmia Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. schwartzmand@msx.upmc.edu
authors.forename: David
authors.initials: D
authors.lastname: Schwartzman
authors.forename: Shailesh Kumar
authors.initials: SK
authors.lastname: Musley
authors.forename: Charles
authors.initials: C
authors.lastname: Swerdlow
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hoyt
authors.forename: Eduardo N
authors.initials: EN
authors.lastname: Warman
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology / Q000628:therapy*; D015331:Cohort Studies; D017147:Defibrillators, Implantable; D004867:Equipment Design; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors