title: Localization of the initial fibrillatory cycle in patients with paroxysmal atrial fibrillation.
abstract: BACKGROUND
  Recent reports suggest the presence of conduction delay in the posterior septal region during sinus rhythm in patients with lone paroxysmal atrial fibrillation (AF).
  
  
  OBJECTIVE
  To explore the location of intra-atrial conduction delay associated with initiation of AF.
  
  
  METHODS
  In 8 lone AF patients (51 +/- 10 years), 20 AF paroxysms were induced during electrophysiological examination. Bipolar electrograms were acquired from a 10-polar catheter in the coronary sinus (CS), a 4-polar His bundle catheter, and a 20-polar Halo catheter in the right atrium.
  
  
  RESULTS
  Induced AF paroxysms showed earliest registered atrial activity in interatrial septum (IAS) or proximal CS in 17 cases (85%). Conduction delay at the posterior IAS or proximal CS accompanied induction of 18 AF paroxysms (6 patients). Atrial activation sequence at the beginning of the AF paroxysms was stable and reproducible in six repeatedly induced AF episodes (3 patients).
  
  
  CONCLUSIONS
  In lone AF patients, induction of AF is associated with conduction disturbances in the IAS and proximal CS regions.
authors.affiliation: Department of Cardiology, Lund University, Sweden. ppg@cpr.spb.ru
authors.forename: P G
authors.initials: PG
authors.lastname: Platonov
authors.forename: S
authors.initials: S
authors.lastname: Yuan
authors.forename: E
authors.initials: E
authors.lastname: Hertervig
authors.lastname: Kongstad
authors.forename: L V
authors.initials: LV
authors.lastname: Chireikin
authors.forename: S B
authors.initials: SB
authors.lastname: Olsson
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000503:physiopathology*; D016280:Atrial Function, Right / Q000502:physiology; D004558:Electric Stimulation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology*; D006346:Heart Septum / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged