title: Effect of left atrial circumferential ablation for atrial fibrillation on left atrial transport function.
abstract: BACKGROUND
  The effects of left atrial (LA) circumferential ablation on LA function in patients with atrial fibrillation (AF) have not been well described.
  
  
  OBJECTIVE
  The purpose of this study was to determine the effect of LA circumferential ablation on LA function.
  
  
  METHODS
  Gated, multiphase, dynamic contrast-enhanced computed tomographic (CT) scans of the chest with three-dimensional reconstructions of the heart were used to calculate the LA ejection fraction (EF) in 36 patients with paroxysmal (n = 27) or chronic (n = 9) AF (mean age 55 +/- 11 years) and in 10 control subjects with no history of AF. Because CT scans had to be acquired during sinus rhythm, a CT scan was available both before and after (mean 5 +/- 1 months) LA circumferential ablation (LACA) in only 10 patients. A single CT scan was acquired in 8 patients before and in 18 patients after LACA ablation. Radiofrequency catheter ablation was performed using an 8-mm-tip catheter to encircle the pulmonary veins, with additional lines along the mitral isthmus and the roof.
  
  
  RESULTS
  In patients with paroxysmal AF, LA EF was lower after than before LACA (21% +/- 8% vs 32 +/- 13%, P = .003). LA EF after LA catheter ablation was similar among patients with paroxysmal AF and those with chronic AF (21% +/- 8% vs 23 +/- 13%, P = .7). However, LA EF after LA catheter ablation was lower in all patients with AF than in control subjects (21% +/- 10% vs 47% +/- 5%, P < .001).
  
  
  CONCLUSIONS
  During medium-term follow-up, restoration of sinus rhythm by LACA results in partial return of LA function in patients with chronic AF. However, in patients with paroxysmal AF, LA catheter ablation results in decreased LA function. Whether the impairment in LA function is severe enough to predispose to LA thrombi despite elimination of AF remains to be determined.
authors.affiliation: Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Kristina
authors.initials: K
authors.lastname: Lemola
authors.forename: Benoit
authors.initials: B
authors.lastname: Desjardins
authors.forename: Michael
authors.initials: M
authors.lastname: Sneider
authors.forename: Ian
authors.initials: I
authors.lastname: Case
authors.forename: Aman
authors.initials: A
authors.lastname: Chugh
authors.forename: Eric
authors.initials: E
authors.lastname: Good
authors.forename: Jihn
authors.initials: J
authors.lastname: Han
authors.forename: Kamala
authors.initials: K
authors.lastname: Tamirisa
authors.forename: Ariane
authors.initials: A
authors.lastname: Tsemo
authors.forename: Scott
authors.initials: S
authors.lastname: Reich
authors.forename: David
authors.initials: D
authors.lastname: Tschopp
authors.forename: Petar
authors.initials: P
authors.lastname: Igic
authors.forename: Darryl
authors.initials: D
authors.lastname: Elmouchi
authors.forename: Frank
authors.initials: F
authors.lastname: Bogun
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Ella
authors.initials: E
authors.lastname: Kazerooni
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D016279:Atrial Function, Left; D016022:Case-Control Studies; D017115:Catheter Ablation; D002908:Chronic Disease; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D006329:Heart Conduction System / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D013318:Stroke Volume; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome