title: Spontaneous dissociated firing from the pulmonary veins during ablation of paroxysmal atrial fibrillation: implications and impact on arrhythmia-free survival.
abstract: BACKGROUND
  Following pulmonary vein isolation (PVI) for the treatment of paroxysmal atrial fibrillation (AF), spontaneous dissociated firing (DiFi) from the isolated veins may be observed. Little is known about the significance and prognostic implications of this phenomenon. We sought to determine the relationship between DiFi and ablation outcomes.
  
  
  METHODS
  The study population consisted of 156 paroxysmal AF patients who underwent first time PVI and were found to have spontaneous DiFi from the pulmonary veins (PVs). Their outcomes were compared to a population of 156 propensity-matched controls from our prospectively maintained AF ablation data registry.
  
  
  RESULTS
  DiFi was most frequently observed from the right superior PV and occurred in 89 patients (57.1%). After 24 months of follow-up, patients with DiFi had better success rates compared to those with silent veins after isolation (88.5% vs 75%, P = 0.002). The overall distribution of types of recurrent arrhythmia was similar between DiFi patients and their matched controls (P = NS). During repeat ablations, DiFi patients were less likely to have PV conduction recovery (60% vs 93.3%, P = 0.02). Importantly, none of the veins with DiFi during index procedures was found to have conduction recovery.
  
  
  CONCLUSIONS
  In patients with paroxysmal AF undergoing ablation, DiFi from the PVs after their isolation was associated with improved ablation outcomes. It is possible that DiFi is an indicator of successful durable isolation of the PVs. The findings suggest that confirmation of exit block may be warranted to improve AF ablation outcomes.
authors.affiliation: Center for Atrial Fibrillation, Cleveland Clinic, Cleveland, Ohio 44195, USA.
authors.forename: Ayman A
authors.initials: AA
authors.lastname: Hussein
authors.forename: Asuka
authors.initials: A
authors.lastname: Ozaki
authors.forename: David O
authors.initials: DO
authors.lastname: Martin
authors.forename: Mandeep
authors.initials: M
authors.lastname: Bhargava
authors.forename: Bryan
authors.initials: B
authors.lastname: Baranowski
authors.forename: Thomas
authors.initials: T
authors.lastname: Dresing
authors.forename: Thomas
authors.initials: T
authors.lastname: Callahan
authors.forename: Mohamed
authors.initials: M
authors.lastname: Kanj
authors.forename: Patrick
authors.initials: P
authors.lastname: Tchou
authors.forename: Andrea
authors.initials: A
authors.lastname: Natale
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Lindsay
authors.forename: Walid I
authors.initials: WI
authors.lastname: Saliba
authors.forename: Oussama M
authors.initials: OM
authors.lastname: Wazni
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000453:epidemiology / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000706:statistics & numerical data*; D017115:Catheter Ablation / Q000706:statistics & numerical data*; D018572:Disease-Free Survival; D005260:Female; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D011667:Pulmonary Veins / Q000601:surgery*; D012307:Risk Factors; D016896:Treatment Outcome
keywords: atrial fibrillation; catheter ablation; outcomes