title: Blocking the pulmonary vein to left atrium conduction in addition to the entrance block enhances clinical efficacy in atrial fibrillation ablation.
abstract: BACKGROUND
  The unidirectional pulmonary vein (PV) to left atrium (LA) conduction after achieving PV entrance block has not been evaluated.
  
  
  METHODS
  Circumferential PV isolation was performed in 573 consecutive patients with atrial fibrillation (AF). The unidirectional PV to LA conduction and its influence on clinical outcomes were evaluated.
  
  
  RESULTS
  A total of 341 ipsilateral PVs (29.7%) with spontaneous activities (SAs) were documented in 231 patients (40.3%). The unidirectional PV to LA conduction was confirmed in 11 ipsilateral PVs (3.2%) of 11 patients (4.8%). Patients were classified to three groups: Group A (had unidirectional PV to LA conduction during SAs), Group B (with SAs but without PV to LA conduction), and Group C (without SAs). During a 30-minute observation, the reconnection incidence was higher in Group A (45.4%) than in Group B (13.9%, P = 0.042) and Group C (11.5%, P = 0.018). The reconnection time was shorter in Group A (10.8 ± 9.8 minutes) than that in Group B (20.7 ± 8.0 minutes, P = 0.037) and Group C (21.2 ± 8.2 minutes, P = 0.022). All 11 PVs were successfully isolated and bidirectional block was achieved.
  
  
  CONCLUSIONS
  Unidirectional entrance block with SAs in PVs may not be a good indication of complete PV isolation. Bidirectional block of the PV-LA junction can reduce the acute PV reconnection and may reduce the chronic AF recurrence in patients undergoing circumferential PV isolation.
authors.affiliation: Department of Cardiology, Shanghai First People's Hospital, College of Medical, Shanghai Jiaotong University, Shanghai, China University of Arizona, Tucson, Arizona, USA. shaowen.liu@hotmail.com
authors.forename: Songwen
authors.initials: S
authors.lastname: Chen
authors.forename: Weidong
authors.initials: W
authors.lastname: Meng
authors.forename: Ding
authors.initials: D
authors.lastname: Sheng He
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Yan
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu-Ge
authors.forename: Shaowen
authors.initials: S
authors.lastname: Liu
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000601:surgery*; D017115:Catheter Ablation / Q000706:statistics & numerical data*; D002681:China / Q000453:epidemiology; D005260:Female; D006325:Heart Atria / Q000601:surgery*; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011667:Pulmonary Veins / Q000601:surgery*; D012008:Recurrence; D016896:Treatment Outcome