title: Spectral analysis identifies sites of high-frequency activity maintaining atrial fibrillation in humans.
abstract: BACKGROUND
  The identification of sites of dominant activation frequency during atrial fibrillation (AF) in humans and the effect of ablation at these sites have not been reported.
  
  
  RESULTS
  Thirty-two patients undergoing AF ablation (19 paroxysmal, 13 permanent) during ongoing arrhythmia were studied. Electroanatomic mapping was performed, acquiring 126+/-13 points per patient throughout both atria and coronary sinus. At each point, 5-second electrograms were obtained to determine the highest-amplitude frequency on spectral analysis and to construct 3D dominant frequency (DF) maps. The temporal stability of the recording interval was confirmed in a subset. Ablation was performed with the operator blinded to the DF maps. The effect of ablation at sites with or without high-frequency DF sites (maximal frequencies surrounded by a decreasing frequency gradient > or =20%) was evaluated by determining the change in AF cycle length (AFCL) and the termination and inducibility of AF. The spatial distribution of the DF sites was different in patients with paroxysmal and permanent AF; paroxysmal AF patients were more likely to harbor the DF site within the pulmonary vein, whereas in permanent AF, atrial DF sites were more prevalent. Ablation at a DF site resulted in significant prolongation of the AFCL (180+/-30 to 198+/-40 ms; P<0.0001; kappa=0.77), whereas in the absence of a DF site, there was no change in AFCL (169+/-22 to 170+/-22 ms; P=0.4). AF terminated during ablation in 17 of 19 patients with paroxysmal and 0 of 13 with permanent AF (P<0.0001). When 2 patients with nonsustained AF during mapping were excluded, 13 of 15 (87%) had AF termination at DF sites (54% at the initially ablated DF site): 11 pulmonary veins and 2 atrial. In addition, AF could no longer be induced in 69% with termination of AF at a DF site. There were no significant differences in the number or percentage of DF sites detected (5.4+/-1.6 versus 4.9+/-2.1; P=0.3) and ablated (1.9+/-1.0 versus 2.4+/-1.0; P=0.3) in those with and without AF termination. The duration of radiofrequency ablation to achieve termination was significantly shorter than that delivered in those with persisting AF (34.8+/-24.0 versus 73.5+/-22.9 minutes; P=0.0002). All patients with persisting AF had additional DF sites outside the ablated zones.
  
  
  CONCLUSIONS
  Spectral analysis and frequency mapping identify localized sites of high-frequency activity during AF in humans with different distributions in paroxysmal and permanent AF. Ablation at these sites results in prolongation of the AFCL and termination of paroxysmal AF, indicating their role in the maintenance of AF.
authors.affiliation: Hôpital Cardiologique du Haut-Lévêque, Université Victor Segalen Bordeaux II, Bordeaux, France.
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
authors.forename: Omer
authors.initials: O
authors.lastname: Berenfeld
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
authors.forename: Ravi
authors.initials: R
authors.lastname: Vaidyanathan
authors.forename: Li-Fern
authors.initials: LF
authors.lastname: Hsu
authors.forename: Stéphane
authors.initials: S
authors.lastname: Garrigue
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Martin
authors.initials: M
authors.lastname: Rotter
authors.forename: Fréderic
authors.initials: F
authors.lastname: Sacher
authors.forename: Christophe
authors.initials: C
authors.lastname: Scavée
authors.forename: Robert
authors.initials: R
authors.lastname: Ploutz-Snyder
authors.forename: José
authors.initials: J
authors.lastname: Jalife
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
mesh_terms: D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000503:physiopathology* / Q000628:therapy; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography / Q000379:methods; D004594:Electrophysiology / Q000379:methods; D006339:Heart Rate; D000078702:Radiofrequency Therapy
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone