title: Epicardial connections between the pulmonary veins and left atrium: relevance for atrial fibrillation ablation.
abstract: BACKGROUND
  Some observations support the existence of epicardial connections (ECs) between ipsilateral pulmonary veins (vein to vein ECs [VVECs]), and we have observed venoatrial ECs inserted at distance from the pulmonary vein ostium (vein to atrium ECs [VAECs]). Our aim was to determine the prevalence of ECs and their relevance for pulmonary vein isolation.
  
  
  RESULTS
  We studied 100 consecutive patients with drug-refractory atrial fibrillation who underwent ostial pulmonary vein isolation by cooled radiofrequency catheter ablation. A VVEC was identified if pulmonary vein pacing activated the ipsilateral vein before the atrium, requiring ablation of both venous ostia to isolate either pulmonary vein. A VAEC was identified if pacing produced atrial breakthrough located at distance from the venous ostium, requiring extraostial ablation to isolate the pulmonary vein. Patients with ECs (20%) were younger (P = 0.02) and had a higher prevalence of structural heart disease (P = 0.01) than patients without ECs. VVECs and VAECs were identified in 32 pulmonary veins (10%) and VAECs in 10 veins (3%). Veins with ECs had a higher rate of early recurrence of conduction following isolation (29% vs 11%; P = 0.01).
  
  
  CONCLUSIONS
  Twenty percent of patients with atrial fibrillation had ECs resistant to ostial ablation in one or more pulmonary veins. Isolating veins with ECs may require a different ablation approach. These connections are associated with an increased rate of early recurrence of conduction. (J Cardiovasc Electrophysiol, Vol. 22, pp. 149-159, February 2011).
authors.affiliation: Unit of Arrhythmias, Cardiovascular Institute, San Carlos University Hospital, Madrid, Spain. nperez.hcsc@salud.madrid.org
authors.forename: Nicasio
authors.initials: N
authors.lastname: Pérez-Castellano
authors.forename: Julián
authors.initials: J
authors.lastname: Villacastín
authors.forename: Jorge
authors.initials: J
authors.lastname: Salinas
authors.forename: Mercedes
authors.initials: M
authors.lastname: Vega
authors.forename: Javier
authors.initials: J
authors.lastname: Moreno
authors.forename: Manuel
authors.initials: M
authors.lastname: Doblado
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ruiz
authors.forename: Carlos
authors.initials: C
authors.lastname: Macaya
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery*; D018780:Body Surface Potential Mapping; D005260:Female; D006325:Heart Atria / Q000503:physiopathology* / Q000601:surgery; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000503:physiopathology* / Q000601:surgery; D011667:Pulmonary Veins / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome