title: An interactive platform to guide catheter ablation in human persistent atrial fibrillation using dominant frequency, organization and phase mapping.
abstract: OBJECTIVE
  Optimal targets for persistent atrial fibrillation (persAF) ablation are still debated. Atrial regions hosting high dominant frequency (HDF) are believed to participate in the initiation and maintenance of persAF and hence are potential targets for ablation, while rotor ablation has shown promising initial results. Currently, no commercially available system offers the capability to automatically identify both these phenomena. This paper describes an integrated 3D software platform combining the mapping of both frequency spectrum and phase from atrial electrograms (AEGs) to help guide persAF ablation in clinical cardiac electrophysiological studies.
  
  
  METHODS
  30s of 2048 non-contact AEGs (EnSite Array, St. Jude Medical) were collected and analyzed per patient. After QRST removal, the AEGs were divided into 4s windows with a 50% overlap. Fast Fourier transform was used for DF identification. HDF areas were identified as the maximum DF to 0.25Hz below that, and their centers of gravity (CGs) were used to track their spatiotemporal movement. Spectral organization measurements were estimated. Hilbert transform was used to calculate instantaneous phase.
  
  
  RESULTS
  The system was successfully used to guide catheter ablation for 10 persAF patients. The mean processing time was 10.4 ± 1.5min, which is adequate comparing to the normal electrophysiological (EP) procedure time (120∼180min).
  
  
  CONCLUSIONS
  A customized software platform capable of measuring different forms of spatiotemporal AEG analysis was implemented and used in clinical environment to guide persAF ablation. The modular nature of the platform will help electrophysiological studies in understanding of the underlying AF mechanisms.
authors.affiliation: Department of Engineering, University of Leicester, UK; Department of Cardiovascular Science, University of Leicester, UK.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Biomedical Engineering, Center for Engineering, Modelling and Applied Social Sciences, Universidade Federal do ABC, Brazil; Bioengineering Division, Heart Institute (InCor), Brasil.
authors.forename: João L
authors.initials: JL
authors.lastname: Salinet
authors.affiliation: Department of Engineering, University of Leicester, UK; Biomedical Engineering, Center for Engineering, Modelling and Applied Social Sciences, Universidade Federal do ABC, Brazil.
authors.forename: Tiago P
authors.initials: TP
authors.lastname: Almeida
authors.affiliation: Institute of Sound and Vibration Research, University of Southampton, UK.
authors.forename: Frederique J
authors.initials: FJ
authors.lastname: Vanheusden
authors.affiliation: Department of Cardiovascular Science, University of Leicester, UK; University Hospitals of Leicester NHS Trust, UK.
authors.forename: Gavin S
authors.initials: GS
authors.lastname: Chu
authors.affiliation: Department of Cardiovascular Science, University of Leicester, UK; University Hospitals of Leicester NHS Trust, UK; National Institute for Health Research Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital, UK.
authors.forename: G André
authors.initials: GA
authors.lastname: Ng
authors.affiliation: Department of Engineering, University of Leicester, UK; National Institute for Health Research Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital, UK. Electronic address: fss1@leicester.ac.uk.
authors.forename: Fernando S
authors.initials: FS
authors.lastname: Schlindwein
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D006321:Heart / Q000502:physiology; D006801:Humans; D012984:Software
keywords: Atrial fibrillation; Catheter ablation; Diagnostic software; Frequency mapping; Intracardiac electrogram; Noncontact mapping; Phase mapping