title: Minimum vs. maximum left atrial volume for prediction of first atrial fibrillation or flutter in an elderly cohort: a prospective study.
abstract: OBJECTIVE
  We sought to compare the predictive power and reproducibility between minimum and maximum left atrial (LA) volume for the development of first atrial fibrillation (AF)/flutter.
  
  
  RESULTS
  This prospective study included 574 adults, mean age 74+/-6 years, in sinus rhythm, and had no history or evidence of prior atrial arrhythmias. During a mean follow-up of 1.9+/-1.2 years, 30 (5.2%) developed first AF/flutter. The 3-year risk estimates of freedom from AF/flutter by tertiles of minimum and maximum LA volumes were, respectively, 97, 87, and 74% (P<0.0006) and 94, 85, and 78% (P=0.03). Minimum LA volume was incremental to clinical and other echocardiographic parameters of AF/flutter prediction [per tertile, hazard ratio (HR) 2.4], as was maximum LA volume (per tertile, HR 1.8) in a separate model. When both volumes were entered into the same model and adjusting for covariates, minimum but not maximum LA volume retained significance. However, in terms of interobserver reproducibility, maximum LA volume compared more favourably (mean difference 3.1+/-7.1 vs. 7.4+/-7.3 mL/m(2)).
  
  
  CONCLUSIONS
  Minimal LA volume was an independent predictor of first AF/flutter. Although it was marginally superior to maximal LA volume in terms of predictive ability, the interobserver variability was greater.
authors.affiliation: Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, 200 First Street, SW, Rochester, MN 55905, USA.
authors.forename: Kaniz
authors.initials: K
authors.lastname: Fatema
authors.forename: Marion E
authors.initials: ME
authors.lastname: Barnes
authors.forename: Kent R
authors.initials: KR
authors.lastname: Bailey
authors.forename: Walter P
authors.initials: WP
authors.lastname: Abhayaratna
authors.forename: Steven
authors.initials: S
authors.lastname: Cha
authors.forename: James B
authors.initials: JB
authors.lastname: Seward
authors.forename: Teresa S M
authors.initials: TS
authors.lastname: Tsang
mesh_terms: D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001282:Atrial Flutter / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006325:Heart Atria / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D011446:Prospective Studies; D012307:Risk Factors; D014463:Ultrasonography