title: Fibrillating areas isolated within the left atrium after radiofrequency linear catheter ablation.
abstract: BACKGROUND
  Nonpulmonary vein sources have been implicated as potential drivers of atrial fibrillation (AF). This observational study describes regions of fibrillating atrial tissue isolated inadvertently from the left atrium (LA) following linear catheter ablation for AF.
  
  
  RESULTS
  We report four patients with persistent/permanent AF who underwent pulmonary vein isolation with additional linear lesions and who presented with recurrent AF (mean AF cycle length [AFCL] 175-270 ms). Further catheter ablation resulted in the inadvertent electrical isolation of significant areas of the LA in which AF persisted at the same AFCL as was measured prior to disconnection, despite the restoration of sinus rhythm (SR) in all other left and right atrial areas, strongly suggesting that these islands were driving the remaining atria into fibrillation. The disconnected areas were located in the lateral LA, including the left atrial appendage (LAA) in three patients (limited to the LAA in one) and in the posterior LA in one patient. These isolated fibrillating regions represented 15-24% of the global LA surface, as estimated by electroanatomic mapping.
  
  
  CONCLUSIONS
  Fibrillation can be maintained within electrically isolated regions of the LA following catheter ablation of AF, demonstrating the importance of atrial drivers in the maintenance of AF. Further mapping of these drivers is needed to characterize their mechanism and thereby allow for a more specific ablation strategy.
authors.affiliation: Service de Rythmologie, Hôpital Cardiologique du Haut-Lévêque and the Université Victor Segalen Bordeaux II, Bordeaux-Pessac, France. rostock@uke.uni-hamburg.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Rostock
authors.forename: Martin
authors.initials: M
authors.lastname: Rotter
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Fréderic
authors.initials: F
authors.lastname: Sacher
authors.forename: Anders
authors.initials: A
authors.lastname: Jönsson
authors.forename: Mark D
authors.initials: MD
authors.lastname: O'Neill
authors.forename: Li-Fern
authors.initials: LF
authors.lastname: Hsu
authors.forename: Jacques
authors.initials: J
authors.lastname: Clémenty
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery