title: Identification of pulmonary vein foci by non-contact mapping in patients with paroxysmal atrial fibrillation.
abstract: OBJECTIVE
  Ectopies from the pulmonary veins may cause paroxysmal atrial fibrillation and their discrete ablation may be curative. In the absence of focal activity during the procedure, identification of target sites with conventional techniques is difficult. We investigated the feasibility of non-contact mapping (EnSite) for identification and successful ablation of pulmonary vein foci in such cases.
  
  
  RESULTS
  We studied 7 patients with idiopathic paroxysmal atrial fibrillation referred for percutaneous ablation and not presenting spontaneous or inducible atrial premature beats during the procedure. An EnSite balloon catheter and an ablation catheter (NaviStar) were placed inside the left atrium. The ablation catheter was also used for electroanatomic mapping (CARTO) of specific sites. Multiphasic pulmonary vein potentials were detected on virtual electrograms and tagged on the non-contact map and confirmed with conventional mapping. The procedural endpoint was elimination or dissociation of the multiphasic potential. Non-contact mapping identified 13 foci of multiphasic potentials in the seven patients (5 foci were initially identified by EnSite), and discrete ablation suppressed 9 of them (69%). Six months later, 4 of the 5 patients in whom all foci were suppressed remain asymptomatic, in sinus rhythm, under no medication.
  
  
  CONCLUSIONS
  In patients with paroxysmal atrial fibrillation and no ectopic activity during electrophysiological study virtual electrograms may complement conventional techniques in detecting hidden pulmonary vein foci and may be used to evaluate ablation efficacy.
authors.affiliation: Serviço de Cardiologia, Hospital de Santa Cruz, Carnaxide, Portugal. padragao@netcabo.pt
authors.forename: Pedro
authors.initials: P
authors.lastname: Adragão
authors.forename: Diogo
authors.initials: D
authors.lastname: Cavaco
authors.forename: Carlos
authors.initials: C
authors.lastname: Aguiar
authors.forename: José
authors.initials: J
authors.lastname: Palos
authors.forename: Francisco
authors.initials: F
authors.lastname: Morgado
authors.forename: Regina
authors.initials: R
authors.lastname: Ribeiras
authors.forename: Miguel
authors.initials: M
authors.lastname: Abecasis
authors.forename: José
authors.initials: J
authors.lastname: Neves
authors.forename: Daniel
authors.initials: D
authors.lastname: Bonhorst
authors.forename: Ricardo
authors.initials: R
authors.lastname: Seabra-Gomes
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation; D002404:Catheterization; D004594:Electrophysiology; D005260:Female; D006325:Heart Atria / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000002:abnormalities* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery