title: Panoramic characterization of endocardial left atrial activation during human persistent AF: Insights from non-contact mapping.
abstract: BACKGROUND
  The relative importance of focal drivers, multiple wavelets, rotors and endocardial-epicardial circuits in the maintenance of persistent AF remains unclear. Our objective was to characterize AF wavefront (WF) dynamics during persistent AF.
  
  
  METHODS
  The Ensite 3000 (St Jude Medical) non-contact mapping system was used to map the LA of 15 patients with persistent AF. Wavefronts were classified into planar WFs, rotors or focal WFs. For each new WF the site of origin, the unipolar electrogram, and propagation patterns were determined.
  
  
  RESULTS
  AF was characterized by highly unstable patterns of activation with random combinations of 1-2 propagating planar wavefronts alternating with focal activations in a dynamic process. Stable reentry circuits and rotors were never seen. A total of 499 wavefront patterns were analyzed in this study (416 planar wavefronts and 83 focal wavefronts). In an individual patient planar WFs accounted for 67±35% of activations with lifespans of 98±86ms. Focal activations accounted for 29.7±33.5% of activations with lifespans of 76±95ms. The most common sites for new WF generation were the PVs (33%), LA roof (23%), anterior LA (15%), LAA (11%), and posterior LA (8%). The most common unipolar electrogram morphologies observed were QS pattern (34%), rS (29%), CFAE (26%), QR (7%) and Rs (4%), suggesting that WFs may originate from both the endocardial and epicardial surfaces.
  
  
  CONCLUSIONS
  Human persistent AF is characterized by the formation of highly unstable WFs consisting of various combinations of one to two planar WFs and brief focal activations without any evidence of rotors or sustained focal sources.
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; The Department of Medicine, The University of Melbourne, Australia.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Lee
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Alex J A
authors.initials: AJ
authors.lastname: McLellan
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Hunter
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Lovell
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Finlay
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Waqas
authors.initials: W
authors.lastname: Ullah
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Mehul B
authors.initials: MB
authors.lastname: Dhinoja
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Sporton
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Earley
authors.affiliation: Cardiovascular Biomedical Research Unit, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom. Electronic address: Richard.Schilling@bartshealth.nhs.uk.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schilling
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D004699:Endocardium / Q000503:physiopathology*; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged
keywords: Atrial fibrillation; Electrogram; Non-contact mapping; Rotor; Wavefront