title: Noninvasive characterization of epicardial activation in humans with diverse atrial fibrillation patterns.
abstract: BACKGROUND
  Various mechanisms of atrial fibrillation (AF) have been demonstrated experimentally. Invasive methods to study these mechanisms in humans have limitations, precluding continuous mapping of both atria with sufficient resolution. In this article, we present continuous biatrial epicardial activation sequences of AF in humans using noninvasive electrocardiographic imaging (ECGI).
  
  
  RESULTS
  In the testing phase, ECGI accuracy was evaluated by comparing ECGI with co-registered CARTO images during atrial pacing in 6 patients. Additionally, correlative observations from catheter mapping and ablation were compared with ECGI in 3 patients. In the study phase, ECGI maps during AF in 26 patients were analyzed for mechanisms and complexity. ECGI noninvasively imaged the low-amplitude signals of AF in a wide range of patients (97 procedural success). Spatial accuracy for determining initiation sites from pacing was 6 mm. Locations critical to maintenance of AF identified during catheter ablation were identified by ECGI; ablation near these sites restored sinus rhythm. In the study phase, the most common patterns of AF were multiple wavelets (92), with pulmonary vein (69) and non-pulmonary vein (62) focal sites. Rotor activity was seen rarely (15). AF complexity increased with longer clinical history of AF, although the degree of complexity of nonparoxysmal AF varied widely.
  
  
  CONCLUSIONS
  ECGI offers a noninvasive way to map epicardial activation patterns of AF in a patient-specific manner. The results highlight the coexistence of a variety of mechanisms and variable complexity among patients. Overall, complexity generally increased with duration of AF.
authors.affiliation: Cardiac Bioelectricity Center, One Brookings Drive, St Louis, MO 63130-4899, USA.
authors.forename: Phillip S
authors.initials: PS
authors.lastname: Cuculich
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Lindsay
authors.forename: Mitchell N
authors.initials: MN
authors.lastname: Faddis
authors.forename: Richard B
authors.initials: RB
authors.lastname: Schuessler
authors.forename: Ralph J
authors.initials: RJ
authors.lastname: Damiano
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Yoram
authors.initials: Y
authors.lastname: Rudy
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D001281:Atrial Fibrillation / Q000145:classification / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D018780:Body Surface Potential Mapping; D004562:Electrocardiography / Q000379:methods; D004594:Electrophysiology / Q000379:methods; D005260:Female; D018729:Fontan Procedure; D006351:Heart Valves / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed