title: Regional fractionation and dominant frequency in persistent atrial fibrillation: effects of left atrial ablation and evidence of spatial relationship.
abstract: OBJECTIVE
  The aim was to study regional fractionation and dominant frequency (DF) to determine if any relationship exists between the two parameters and also to assess the impact of limited left atrial ablation.
  
  
  RESULTS
  Patients undergoing catheter ablation of persistent AF using three-dimensional navigation were studied. Regional left atrial electrograms were analysed in the frequency domain by assessing DF and organization index (OI), and for degree of fractionation [using complex fractionated electrograms (CFE)-mean] before and after circumferential pulmonary vein and left atrial roof ablation. Twenty-three patients with persistent AF were studied. After ablation, global CFE-mean increased [100 ± 5 to 147 ± 11 ms (P= 0.0003)], DF decreased [6.1 ± 0.2 to 5.3 ± 0.2 Hz (P= 0.0003)], and OI was unchanged [0.27 ± 0.01 to 0.26 ± 0.02, (P= 0.70)]. Comparing sites close to and distant from ablation lines, percentage change in CFE-mean was 94 ± 10 vs. 37 ± 6% (P< 0.0001), DF change was -13 ± 3 vs.-12 ± 2% (P= 0.98), and OI change was 3 ± 6 vs. 10 ± 5% (P= 0.75), respectively. There was modest correlation between CFE-mean and DF points prior to ablation (r = -0.33, P< 0.0001) which was reduced following left atrial ablation (r = -0.24, P= 0.005).
  
  
  CONCLUSIONS
  Left atrial ablation reduces global left atrial DF and decreases the degree of fractionation. Complex fractionated electrograms-mean and DF appear to share only modest spatial correlation and are affected to different extents by ablation, suggesting that they are either separate entities or reflect different components of the same substrate.
authors.affiliation: Department of Cardiovascular Sciences, University of Leicester, Cardiology group, Glenfield Hospital, Leicester LE3 9QP, UK.
authors.forename: Jiun
authors.initials: J
authors.lastname: Tuan
authors.forename: Mohamed
authors.initials: M
authors.lastname: Jeilan
authors.forename: Suman
authors.initials: S
authors.lastname: Kundu
authors.forename: Will
authors.initials: W
authors.lastname: Nicolson
authors.forename: Irene
authors.initials: I
authors.lastname: Chung
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Stafford
authors.forename: G André
authors.initials: GA
authors.lastname: Ng
mesh_terms: D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents; D001281:Atrial Fibrillation / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D017115:Catheter Ablation; D022062:Electrophysiologic Techniques, Cardiac; D055724:Electrophysiological Phenomena / Q000502:physiology; D005260:Female; D006325:Heart Atria / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone