title: Arrhythmic complications after electrical cardioversion of acute atrial fibrillation: the FinCV study.
abstract: OBJECTIVE
  To determine the incidence and risk factors of arrhythmic complications after electrical cardioversion of acute atrial fibrillation (AF).
  
  
  RESULTS
  Our retrospective multicentre study collected data from 7660 cardioversions of acute (<48 h) AF in 3143 consecutive patients. Immediate arrhythmic complications were evaluated after 6906 (90.2%) electrical cardioversions performed in 2868 patients. We also assessed the predictors of arrhythmic complications and whether post-cardioversion bradycardia or asystole led to later a permanent pacemaker implantation. Altogether, 63 (0.9%) electrical cardioversions resulted in bradyarrhythmia in 54 patients. Asystole (>5 s) occurred immediately after 51 cardioversions leading to a short resuscitation in seven cases and two patients needed extrinsic pacing after the cardioversion. In nine cases, asystole was followed by bradycardia. Bradycardic ventricular rate (<40 b.p.m.) alone was seen after 12 procedures. No ventricular arrhythmias needing intervention were detected. Old age [odds ratio (OR) 1.1; 95% confidence interval (CI) 1.05-1.10, P < 0.0001], female sex (OR 2.5; 95% CI 1.4-4.8, P = 0.004), and unsuccessful cardioversion (OR 2.2; 95% CI 1.1-4.6, P = 0.03) were the independent predictors of bradycardic complications. Slow ventricular rate, use of digoxin, beta blocker, or antiarrhythmic medication did not increase the risk of bradycardic complications. Pacemaker was implanted in 24 (44.4%) patients after a median delay of 66 days.
  
  
  CONCLUSIONS
  Bradycardic complications are rare and usually benign after cardioversion of acute AF. They seem to reflect sinus node dysfunction and often result in later implantation of a permanent pacemaker.
authors.affiliation: Heart Center, Turku University Hospital, Kiinamyllynkatu 4-8, FIN-20520 Turku, Finland.
authors.forename: Toni
authors.initials: T
authors.lastname: Grönberg
authors.forename: Ilpo
authors.initials: I
authors.lastname: Nuotio
authors.forename: Marko
authors.initials: M
authors.lastname: Nikkinen
authors.forename: Antti
authors.initials: A
authors.lastname: Ylitalo
authors.forename: Tuija
authors.initials: T
authors.lastname: Vasankari
authors.forename: Juha E K
authors.initials: JE
authors.lastname: Hartikainen
authors.forename: K E Juhani
authors.initials: KE
authors.lastname: Airaksinen
mesh_terms: D000208:Acute Disease; D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy*; D001919:Bradycardia / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D016009:Chi-Square Distribution; D004554:Electric Countershock / Q000009:adverse effects*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006323:Heart Arrest / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology / Q000628:therapy; D006339:Heart Rate; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012849:Sinoatrial Node / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome
keywords: Arrhythmic complication; Atrial fibrillation; Bradycardia; Cardioversion