title: Electrocardiographic spatial loops indicate organization of atrial fibrillation minutes before ablation-related transitions to atrial tachycardia.
abstract: During ablation for atrial fibrillation (AF), it is challenging to anticipate transitions to organized tachycardia (AT). Defining indices of this transition may help to understand fibrillatory conduction and help track therapy.
  
  
  
  To determine the timescale over which atrial fibrillation (AF) organizes en route to atrial tachycardia (AT) using the ECG referenced to intracardiac electrograms.
  
  
  
  In 17 AF patients at ablation (58.7±9.6years; 53% persistent AF) we analyzed spatial loops of atrial activity on the ECG and intracardiac electrograms over successive timepoints. Loops were tracked at precisely 15, 10, 5, 3 and 1min prior to defined transitions of AF to AT.
  
  
  
  Organizational indices reliably quantified changes from AF to AT. Spatiotemporal AF organization on the ECG was identifiable at least 15min before AT was established (p=0.02).
  
  
  
  AF shows anticipatory global organization on the ECG minutes before AT is clinically evident. These results offer a foundation to establish when AF therapy is on an effective path, and for a quantitative classification separating AT from AF.
authors.affiliation: Stanford University, CA, USA.
authors.forename: Tina
authors.initials: T
authors.lastname: Baykaner
authors.affiliation: Stanford University, CA, USA.
authors.forename: Rishi
authors.initials: R
authors.lastname: Trikha
authors.affiliation: Cedars Sinai Medical Center, CA, USA.
authors.forename: Junaid A B
authors.initials: JAB
authors.lastname: Zaman
authors.affiliation: University of California San Diego, CA, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Krummen
authors.affiliation: Stanford University, CA, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Wang
authors.affiliation: Stanford University, CA, USA. Electronic address: sanjiv1@stanford.edu.
authors.forename: Sanjiv M
authors.initials: SM
authors.lastname: Narayan
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D017115:Catheter Ablation; D018450:Disease Progression; D004569:Electroencephalography / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013612:Tachycardia, Ectopic Atrial / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Ablation; Atrial tachycardia; ECG; Fibrillation; Signal processing