title: Predictors of atrial fibrillation after ablation of typical atrial flutter.
abstract: BACKGROUND
  The occurrence of atrial fibrillation (AF) after successful ablation of cavotricuspid isthmus-dependent atrial flutter (CTI-AFL) is an important medical event, but predictors of this event are still controversial.
  
  
  OBJECTIVE
  To determine the incidence of AF and its predictors in patients undergoing ablation of cavotricuspid isthmus-dependent atrial flutter (CTI-AFL).
  
  
  METHODS
  Fifty two patients with CTI-AFL underwent ablation from January 2003 to March 2004, in Instituto do Coração (InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo.
  
  
  RESULTS
  During the mean follow-up period of 26.2 +/- 9.2 months, 16 (30.8%) patients presented AF. The univariate analysis revealed two clinical variables as predictive of the occurrence of AF after ablation of CTI-AFL for three years or longer (RR: 3.00; p = 0.020). In the multivariate analysis, these factors were independent variables associated with the occurrence of AF after ablation of CTI-AFL.
  
  
  CONCLUSIONS
  AF is frequently observed during the follow-up of patients undergoing ablation of CTI-AFL. Persistent CTI-AFL and history of arrhythmia for more than three years are predictors of the occurrence of AF during the clinical follow-up.
authors.affiliation: Instituto do Coração, HC, FM, USP, São Paulo, SP, Brasil. slara@cardiol.br
authors.forename: Sissy Lara de
authors.initials: SL
authors.lastname: Melo
authors.forename: Maurício
authors.initials: M
authors.lastname: Scanavacca
authors.forename: Cristiano
authors.initials: C
authors.lastname: Pisani
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Nascimento
authors.forename: Francisco
authors.initials: F
authors.lastname: Darrieux
authors.forename: Denise
authors.initials: D
authors.lastname: Hachul
authors.forename: Carina
authors.initials: C
authors.lastname: Hardy
authors.forename: Eduardo
authors.initials: E
authors.lastname: Sosa
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000209:etiology; D001282:Atrial Flutter / Q000601:surgery*; D001938:Brazil / Q000453:epidemiology; D017115:Catheter Ablation / Q000009:adverse effects*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged