title: Left atrial function and scar after catheter ablation of atrial fibrillation.
abstract: BACKGROUND
  Catheter ablation of atrial fibrillation (AF) involves extensive radiofrequency ablation (RFA) of the left atrium (LA) around the pulmonary veins. The effect of this therapy on LA function is not fully characterized.
  
  
  OBJECTIVE
  The purpose of this study was to determine whether catheter ablation of AF is associated with a change in LA function.
  
  
  METHODS
  LA and right atrial (RA) systolic function was assessed in 33 consecutive patients with paroxysmal or persistent AF referred for ablation using cardiovascular magnetic resonance (CMR) imaging. Steady-state free precession ECG cine CMR imaging was performed before and after (mean 48 days) AF ablation. All patients underwent circumferential pulmonary vein isolation using an 8-mm tip RFA catheter. High spatial resolution late gadolinium enhancement CMR images of LA scar were obtained in 16 patients.
  
  
  RESULTS
  Maximum LA volume decreased by 15% (P <.001), and LA ejection fraction decreased by 14% (P <.001) after AF ablation. Maximum RA volume decreased by 13% (P = .018), but RA ejection fraction increased by 5% (P = .008). Mean LA scar volume was 8.1 +/- 3.7 mL. A linear correlation was observed between change in LA ejection fraction and scar volume (r = -0.75, P <.001).
  
  
  CONCLUSIONS
  Catheter ablation of AF is associated with decreased LA size and reduced atrial systolic function. This change strongly correlates with the volume of LA scar. This finding may have implications for postprocedural thromboembolic risk and for procedures involving more extensive RFA.
authors.affiliation: Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA. jwylie@bidmc.harvard.edu
authors.forename: John V
authors.initials: JV
authors.lastname: Wylie
authors.forename: Dana C
authors.initials: DC
authors.lastname: Peters
authors.forename: Vidal
authors.initials: V
authors.lastname: Essebag
authors.forename: Warren J
authors.initials: WJ
authors.lastname: Manning
authors.forename: Mark E
authors.initials: ME
authors.lastname: Josephson
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Hauser
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000628:therapy*; D016279:Atrial Function, Left; D017115:Catheter Ablation / Q000009:adverse effects*; D002921:Cicatrix / Q000175:diagnosis / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome