title: Role of triggering pulmonary veins in the maintenance of sustained paroxysmal atrial fibrillation.
abstract: BACKGROUND
  Triggers from thoracic veins have been implicated not only in the initiation, but also in the perpetuation of paroxysmal atrial fibrillation (PAF). To investigate their role we studied the distribution and stability of dominant frequencies (DFs) during PAF and the response to isolation of the triggering pulmonary vein (PV).
  
  
  RESULTS
  Triggering structures inducing PAF were identified during isoproterenol challenge in 26 patients (15 males, 55 ± 8.5 years). During sustained PAF, sequential recordings were made with a decapolar circular mapping catheter from each PV and the left atrial posterior wall (LAPW), together with coronary sinus (CS) and right atrium (RA) recordings. DF was determined using fast Fourier transformation. Recordings were repeated after ≥15 minutes of PAF. Radiofrequency ablation was directed first at the triggering PVs. PAF initiated from the PVs in 24 patients and from RA in two. There was a significant frequency gradient from the triggering structure to the PVs, CS, LAPW, and RA (P < 0.0001). During the second recording, DF decreased at all sites (P < 0.02), but the frequency gradient remained unchanged. Despite isolation of the triggering PV, PAF continued in 53% of patients, although DF measured in the CS was lower. AF termination occurred with contralateral PV isolation in half of the remaining patients and further AF slowing was noted in the rest.
  
  
  CONCLUSIONS
  Triggering structures harbor the fastest activity during sustained PAF pointing to their leading role in arrhythmia perpetuation. However, nontriggering PVs also seem to contribute to PAF maintenance.
authors.affiliation: Second Department of Internal Medicine and Cardiology Centre, University of Szeged, Kor´anyi Fasor 6, 6720 Szeged, Hungary. vtraykov@yahoo.com
authors.forename: Vassil B
authors.initials: VB
authors.lastname: Traykov
authors.forename: Róbert
authors.initials: R
authors.lastname: Pap
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Gingl
authors.forename: Szami
authors.initials: S
authors.lastname: Chadaide
authors.forename: Haris M
authors.initials: HM
authors.lastname: Haqqani
authors.forename: Gergely
authors.initials: G
authors.lastname: Klausz
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Gallardo
authors.forename: Tamás
authors.initials: T
authors.lastname: Forster
authors.forename: David J
authors.initials: DJ
authors.lastname: Callans
authors.forename: László
authors.initials: L
authors.lastname: Sághy
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D018780:Body Surface Potential Mapping / Q000379:methods*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods; D002908:Chronic Disease; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000503:physiopathology* / Q000601:surgery; D025321:Surgery, Computer-Assisted / Q000379:methods; D016896:Treatment Outcome
keywords: dominant frequency; fast Fourier transformation; frequency gradient; paroxysmal atrial fibrillation