title: Interatrial block and interatrial septal thickness in patients with paroxysmal atrial fibrillation undergoing catheter ablation: Long-term follow-up study.
abstract: BACKGROUND
  Interatrial block (IAB) is a strong predictor of recurrence of atrial fibrillation (AF). IAB is a conduction delay through the Bachman region, which is located in the upper region of the interatrial space. During IAB, the impulse travels from the right atrium to the interatrial septum (IAS) and coronary sinus to finally reach the left atrium in a caudocranial direction. No relation between the presence of IAB and IAS thickness has been established yet.
  
  
  OBJECTIVE
  To determine whether a correlation exists between the degree of IAB and the thickness of the IAS and to determine whether IAS thickness predicts AF recurrence.
  
  
  METHODS
  Sixty-two patients with diagnosis of paroxysmal AF undergoing catheter ablation were enrolled. IAB was defined as P-wave duration ≥120 ms. IAS thickness was measured by cardiac computed tomography.
  
  
  RESULTS
  Among 62 patients with paroxysmal AF, 45 patients (72%) were diagnosed with IAB. Advanced IAB was diagnosed in 24 patients (39%). Forty-seven patients were male. During a mean follow-up period of 49.8 ± 22 months (range 12-60 months), 32 patients (51%) developed AF recurrence. IAS thickness was similar in patients with and without IAB (4.5 ± 2.0 mm vs. 4.0 ± 1.4 mm; p = .45) and did not predict AF. Left atrial size was significantly enlarged in patients with IAB (40.9 ± 5.7 mm vs. 37.2 ± 4.0 mm; p = .03). Advanced IAB predicted AF recurrence after the ablation (OR: 3.34, CI: 1.12-9.93; p = .03).
  
  
  CONCLUSIONS
  IAS thickness was not significantly correlated to IAB and did not predict AF recurrence. IAB as previously demonstrated was an independent predictor of AF recurrence.
authors.affiliation: Heart Rhythm Service, Kingston General Hospital, Queen's University, Kingston, ON, Canada.
authors.forename: Enes E
authors.initials: EE
authors.lastname: Gul
authors.affiliation: Department of Cardiology, Kingston General Hospital, Queen's University, Kingston, ON, Canada.
authors.forename: Raveen
authors.initials: R
authors.lastname: Pal
authors.affiliation: Hull & East Yorkshire NHS Trust and Hull York Medical School, Hull, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Caldwell
authors.affiliation: Heart Rhythm Service, Kingston General Hospital, Queen's University, Kingston, ON, Canada.
authors.forename: Usama
authors.initials: U
authors.lastname: Boles
authors.affiliation: Department of Public Health Sciences, Queen's University, Kingston, ON, Canada.
authors.forename: Wilma
authors.initials: W
authors.lastname: Hopman
authors.affiliation: Heart Rhythm Service, Kingston General Hospital, Queen's University, Kingston, ON, Canada.
authors.forename: Benedict
authors.initials: B
authors.lastname: Glover
authors.affiliation: Heart Rhythm Service, Kingston General Hospital, Queen's University, Kingston, ON, Canada.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Michael
authors.affiliation: Heart Rhythm Service, Kingston General Hospital, Queen's University, Kingston, ON, Canada.
authors.forename: Damian
authors.initials: D
authors.lastname: Redfearn
authors.affiliation: Heart Rhythm Service, Kingston General Hospital, Queen's University, Kingston, ON, Canada.
authors.forename: Chris
authors.initials: C
authors.lastname: Simpson
authors.affiliation: Heart Rhythm Service, Kingston General Hospital, Queen's University, Kingston, ON, Canada.
authors.forename: Hoshiar
authors.initials: H
authors.lastname: Abdollah
authors.affiliation: Heart Rhythm Service, Kingston General Hospital, Queen's University, Kingston, ON, Canada.
authors.forename: Adrian
authors.initials: A
authors.lastname: Baranchuk
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications* / Q000601:surgery; D054087:Atrial Septum / Q000000981:diagnostic imaging*; D001837:Body Weights and Measures / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D000074021:Interatrial Block / Q000150:complications / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013995:Time; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: atrial fibrillation; interatrial bock; interatrial septal thickness; recurrence