title: Interatrial right-to-left conduction in patients with paroxysmal atrial fibrillation.
abstract: OBJECTIVE
  We wanted to illustrate the right-to-left impulse propagation routes during sinus in patients with paroxysmal atrial fibrillation (PAF), as alterations in conduction patterns have been linked to the pathogenesis of PAF, and as no large patient materials have been published.
  
  
  METHODS
  Patients underwent 3-D electroanatomical contact mapping prior to catheter ablation. The site of the earliest left atrial (LA) activation was determined.
  
  
  RESULTS
  Three different interatrial routes were identified, either as solitary pathways (36/50 patients, 72%) or in their combinations (14/50). Bachmann's bundle (BB) was involved in the majority of the cases with solitary routes (25/36). More seldom, impulse propagation occurred near the oval fossa (FO) (7/36) or the coronary sinus ostium (4/36). In patients with combined routes, both the BB (10/14) and FO routes (11/14) were included in most cases.
  
  
  CONCLUSIONS
  In PAF patients, LA can be activated during sinus rhythm through three distinct connections, either encompassing a single route or via any combination of these connections. In one third, the earliest LA activation occurs outside BB. The knowledge of the propagation patterns may give insight into the pathophysiology of PAF and into refining ablation therapy.
authors.affiliation: Department of Cardiology, Helsinki University Central Hospital, Helsinki, Finland. jari.tapanainen@jippii.fi
authors.forename: Jari M
authors.initials: JM
authors.lastname: Tapanainen
authors.forename: Raija
authors.initials: R
authors.lastname: Jurkko
authors.forename: Fredrik
authors.initials: F
authors.lastname: Holmqvist
authors.forename: Daniela
authors.initials: D
authors.lastname: Husser
authors.forename: Ole
authors.initials: O
authors.lastname: Kongstad
authors.forename: Markku
authors.initials: M
authors.lastname: Mäkijärvi
authors.forename: Lauri
authors.initials: L
authors.lastname: Toivonen
authors.forename: Pyotr G
authors.initials: PG
authors.lastname: Platonov
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology*; D018780:Body Surface Potential Mapping / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D055815:Young Adult