title: Mirror image atrial dilatation in adult patients with atrial fibrillation and congenital heart disease.
abstract: BACKGROUND
  Atrial fibrillation (AF) is largely regarded to be initiated from left atrial (LA) dilatation, with subsequent dilatation of the right atrium (RA) in those who progress to chronic AF. We hypothesized that in adult patients with right-sided congenital heart disease (CHD) and AF, RA dilatation will predominate with subsequent dilatation of the left atrium, as a mirror image.
  
  
  METHODS
  Adult patients with diagnosis of right-sided, ASD or left-sided CHD who had undergone an echocardiographic study and electrocardiographic recording in 2007 were included. RA and LA area were measured from the apical view. AF was diagnosed from a 12-lead electrocardiogram or Holter recording. A multivariate logistic regression model was used to identify predictors of AF and linear regression models were performed to measure relationship between RA and LA area and AF.
  
  
  RESULTS
  A total of 291 patients were included in the study. Multivariate analysis showed that age (p=0.0001), RA (p=0.025) and LA area (p=0.0016) were significantly related to AF. In patients with pure left-sided pathologies, there was progressive and predominant LA dilatation that paralleled the development of AF from none to paroxysmal to chronic AF. In patients with pure right-sided pathologies, there was a mirror image of progressive and predominant RA dilatation with the development of AF.
  
  
  CONCLUSIONS
  We observed a mirror image atrial dilatation in patients with right sided disease and AF. This may provide novel mechanistic insight as to the origin of AF in these patients and deserves further studying in the form of targeted electrophysiological studies.
authors.affiliation: McGill Adult Unit for Congenital Heart Disease Excellence, Montreal, Canada.
authors.forename: Judith
authors.initials: J
authors.lastname: Bouchardy
authors.forename: Ariane J
authors.initials: AJ
authors.lastname: Marelli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Martucci
authors.forename: Natalie
authors.initials: N
authors.lastname: Bottega
authors.forename: Judith
authors.initials: J
authors.lastname: Therrien
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016208:Databases, Factual; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography; D055815:Young Adult