title: Left atrial global and regional function in patients with paroxysmal atrial fibrillation has already been impaired before enlargement of left atrium: velocity vector imaging echocardiography study.
abstract: OBJECTIVE
  Left atrial volume (LAV) has been proposed as a predictor of atrial fibrillation (AF) and LA function has been investigated by velocity vector imaging (VVI) echocardiography. The aim of this study was to determine whether LA function was associated with the existence of AF.
  
  
  RESULTS
  We examined emptying function (EF) as a global function and strain rate (SR) as a regional function of LA function during three phases of the cardiac cycle (reservoir, conduit, and booster pump phase). The parameters were measured (apical four-chamber view) by VVI in 302 subjects [126 sinus rhythm, 91 paroxysmal AF (PAF), and 85 chronic AF]. Global and regional LA function were significantly lower in PAF patients during sinus rhythm (LA total EF: 35 ± 8%; SR at atrial contraction: -0.8 ± 0.3s(-1)) and much lower in chronic AF patients (LA total EF 22 ± 8%) than in subjects with sinus rhythm (LA total EF: 47 ± 7%; SR at atrial contraction: -1.4 ± 0.4s(-1)). In multivariate logistic regression analysis, LA active EF and SR at atrial contraction were independent features of PAF.
  
  
  CONCLUSIONS
  LA function, particularly LA active relaxation and contraction, was lower in PAF patients than in subjects with sinus rhythm, regardless of LA size and age. LA functional impairment was observed regardless of hypertension before LA enlargement in patients with PAF. Reduced LA function, as assessed by VVI, is an important feature of AF as well as LA structure.
authors.affiliation: Department of Cardiology,  Gifu Prefectural General Medical Center, Gifu,  Japan.
authors.forename: Tai
authors.initials: T
authors.lastname: Kojima
authors.forename: Masanori
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Tanaka
authors.forename: Koji
authors.initials: K
authors.lastname: Ono
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hirose
authors.forename: Makoto
authors.initials: M
authors.lastname: Iwama
authors.forename: Takatomo
authors.initials: T
authors.lastname: Watanabe
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Noda
authors.forename: Sachiro
authors.initials: S
authors.lastname: Watanabe
authors.forename: Genzou
authors.initials: G
authors.lastname: Takemura
authors.forename: Shinya
authors.initials: S
authors.lastname: Minatoguchi
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016279:Atrial Function, Left / Q000502:physiology*; D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged