title: Prediction of cardiac rhythm 1 year following cardioversion for atrial fibrillation.
abstract: BACKGROUND
  There is little recent information regarding outcome and its determinants following cardioversion (CV) for atrial fibrillation (AF) or flutter. This study aims to help improve prediction of cardiac rhythm outcome following CV for AF.
  
  
  METHODS
  Cardiac rhythm at 6 weeks and 12 months was documented following elective (EC; n=496) or immediate (IC; n=52) cardioversion for AF or atrial flutter in a single referral centre.
  
  
  RESULTS
  65 and 58% of IC patients remained in sinus rhythm (SR) 6 weeks and 1 year after CV (respectively) compared with 43% and 30% in EC patients (P<0.001). Independent positive predictors of SR 6 weeks after cardioversion included amiodarone therapy (OR 2.04 [1.28-3.33], P<0.01) and atrial flutter (OR 1.85 [1.09-3.13], P<0.05). Negative predictors included the need for >1 shock to achieve SR (OR 1.61 [1.12-2.37], P=0.011) and arrhythmia duration, (OR 0.96 [0.95-0.97], P<0.001). At 1 year, amiodarone, duration of arrhythmia and the need for >1 shock remained independent predictors of rhythm.
  
  
  CONCLUSIONS
  The number of shocks required to achieve SR is a newly demonstrated independent predictor of rhythm outcome after elective CV.
authors.affiliation: Department of Medicine, Otago University-Christchurch, Christchurch, New Zealand. amjadh@cdhb.govt.nz
authors.forename: Amjad K
authors.initials: AK
authors.lastname: Hamid
authors.forename: A Mark
authors.initials: AM
authors.lastname: Richards
authors.forename: Ian G
authors.initials: IG
authors.lastname: Crozier
authors.forename: John G
authors.initials: JG
authors.lastname: Lainchbury
authors.forename: Iain
authors.initials: I
authors.lastname: Melton
authors.forename: Paul G
authors.initials: PG
authors.lastname: Bridgman
authors.forename: Suetonia C
authors.initials: SC
authors.lastname: Palmer
authors.forename: Chris M
authors.initials: CM
authors.lastname: Frampton
authors.forename: M Gary
authors.initials: MG
authors.lastname: Nicholls
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D001282:Atrial Flutter / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D016009:Chi-Square Distribution; D004554:Electric Countershock / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents; D000925:Anticoagulants; D000638:Amiodarone