title: Long-term effects of catheter ablation for lone atrial fibrillation: progressive atrial electroanatomic substrate remodeling despite successful ablation.
abstract: BACKGROUND
  Whether curative ablation can prevent progression of the atrial electroanatomic remodeling associated with atrial fibrillation (AF) is not known.
  
  
  OBJECTIVE
  The purpose of this study was to determine whether successful radiofrequency ablation (RFA) of AF can prevent progression of the atrial substrate associated with AF.
  
  
  METHODS
  Detailed right atrial electroanatomic maps from 11 patients without apparent structural heart disease undergoing RFA of AF at baseline and ≥6 months following successful RFA were compared to 11 control patients undergoing electrophysiologic evaluation of supraventricular tachycardia. Bipolar voltage, conduction, effective refractory periods (ERPs), and signal complexity were assessed.
  
  
  RESULTS
  At baseline compared with the control group, the AF group demonstrated (1) lower voltage (P <.001); (2) slowed conduction (P = .005); (3) more prevalent complex signals (P <.001); (4) prolonged regional refractoriness (P <.05), and (5) left atrial dilation (P = .01). At 10 ± 13 month follow-up, the AF group demonstrated the following compared to baseline: (1) lower voltage (P <.05); (2) either no improvement or further slowing of conduction; (3) further prolongation of regional refractoriness (P <.05); and (4) reversal of left atrial dilation (P <.05).
  
  
  CONCLUSIONS
  Patients with lone AF demonstrate evidence of an abnormal atrial substrate at baseline compared to control patients without AF. This substrate does not appear to reverse even after successful catheter ablation. These findings may have implications for long-term outcomes of ablation and for timing of ablative intervention.
authors.affiliation: Department of Cardiology, Royal Melbourne Hospital and Department of Medicine, University of Melbourne, Melbourne, Australia.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Teh
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kistler
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Lee
authors.forename: Caroline
authors.initials: C
authors.lastname: Medi
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Heck
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Spence
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Morton
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Kalman
mesh_terms: D001281:Atrial Fibrillation / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000295:instrumentation* / Q000379:methods; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D018450:Disease Progression; D005260:Female; D006325:Heart Atria / Q000473:pathology / Q000601:surgery*; D006329:Heart Conduction System; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013223:Statistics as Topic; D013318:Stroke Volume; D013617:Tachycardia, Supraventricular / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome; D016277:Ventricular Function, Left