title: Clinical mapping approach to diagnose electrical rotors and focal impulse sources for human atrial fibrillation.
abstract: BACKGROUND
  The perpetuating mechanisms for human atrial fibrillation (AF) remain undefined. Localized rotors and focal beat sources may sustain AF in elegant animal models, but there has been no direct evidence for localized sources in human AF using traditional methods. We developed a clinical computational mapping approach, guided by human atrial tissue physiology, to reveal sources of human AF.
  
  
  RESULTS
  In 49 AF patients referred for ablation (62 ± 9 years; 30 persistent), we defined repolarization dynamics using monophasic action potentials (MAPs) and recorded AF activation from 64-pole basket catheters in left atrium and, in n = 20 patients, in both atria. Careful positioning of basket catheters was required for optimal mapping. AF electrograms at 64-128 electrodes were combined with repolarization and conduction dynamics to construct spatiotemporal AF maps. We observed sustained sources in 47/49 patients, in the form of electrical rotors (n = 57) and focal beats (n = 11) that controlled local atrial activation with peripheral wavebreak (fibrillatory conduction). Patients with persistent AF had more sources than those with paroxysmal AF (2.1 ± 1.0 vs 1.5 ± 0.8, P = 0.02), related to shorter cycle length (163 ± 19 milliseconds vs 187 ± 25 milliseconds, P < 0.001). Approximately one-quarter of sources lay in the right atrium.
  
  
  CONCLUSIONS
  Physiologically guided computational mapping revealed sustained electrical rotors and repetitive focal beats during human AF for the first time. These localized sources were present in 96% of AF patients, and controlled AF activity. These results provide novel mechanistic insights into human AF and lay the foundation for mechanistically tailored approaches to AF ablation.
authors.affiliation: Veterans' Affairs and University of California Medical Centers, San Diego, CA, USA. snarayan@ucsd.edu
authors.forename: Sanjiv M
authors.initials: SM
authors.lastname: Narayan
authors.forename: David E
authors.initials: DE
authors.lastname: Krummen
authors.forename: Wouter-Jan
authors.initials: WJ
authors.lastname: Rappel
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D016275:Atrial Function; D002140:California; D006328:Cardiac Catheterization; D017115:Catheter Ablation; D016009:Chi-Square Distribution; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors