title: Distinctive patterns of dominant frequency trajectory behavior in drug-refractory persistent atrial fibrillation: preliminary characterization of spatiotemporal instability.
abstract: BACKGROUND
  The role of substrates in the maintenance of persistent atrial fibrillation (persAF) remains poorly understood. The use of dominant frequency (DF) mapping to guide catheter ablation has been proposed as a potential strategy, but the characteristics of high DF sites have not been extensively studied. This study aimed to assess the DF spatiotemporal stability using high density noncontact mapping (NCM) in persAF.
  
  
  RESULTS
  Eight persAF patients were studied using NCM during AF. Ventricular far-field cancellation was performed followed by the calculation of DF using Fast Fourier Transform. Analysis of DF stability and spatiotemporal behavior were investigated including characteristics of the highest DF areas (HDFAs). A total of 16,384 virtual electrograms (VEGMs) and 232 sequential high density 3-dimensional DF maps were analyzed. The percentage of DF stable points decreased rapidly over time. Repetition or reappearance of DF values were noted in some instances, occurring within 10 seconds in most cases. Tracking the HDFAs' center of gravity revealed 3 types of propagation behavior, namely (i) local, (ii) cyclical, and (iii) chaotic activity, with the former 2 patterns accounting for most of the observed events.
  
  
  CONCLUSIONS
  DF of individual VEGMs was temporally unstable, although reappearance of DF values occurred at times. Hence, targeting sites of 'peak DF' from a single time frame is unlikely to be a reliable ablation strategy. There appears to be a predominance of local and cyclical activity of HDFAs hinting a potentially nonrandom temporally periodic behavior that provides further mechanistic insights into the maintenance of persAF.
authors.affiliation: Department of Engineering, University of Leicester, Leicester, UK.
authors.forename: João L
authors.initials: JL
authors.lastname: Salinet
authors.affiliation: University Hospitals of Leicester NHS Trust, Leicester, UK.|National Institute for Health Research Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital, Leicester, UK.
authors.forename: Jiun H
authors.initials: JH
authors.lastname: Tuan
authors.affiliation: University Hospitals of Leicester NHS Trust, Leicester, UK.
authors.forename: Alistair J
authors.initials: AJ
authors.lastname: Sandilands
authors.affiliation: University Hospitals of Leicester NHS Trust, Leicester, UK.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Stafford
authors.affiliation: National Institute for Health Research Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital, Leicester, UK.
authors.forename: Fernando S
authors.initials: FS
authors.lastname: Schlindwein
authors.affiliation: National Institute for Health Research Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital, Leicester, UK.|Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.
authors.forename: G André
authors.initials: GA
authors.lastname: Ng
mesh_terms: D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D004351:Drug Resistance; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery; D012008:Recurrence
chemical_list: D000889:Anti-Arrhythmia Agents
keywords: atrial fibrillation; conduction; dominant frequency; dynamics; noncontact mapping; spectrum analysis