title: Low atrial septal pacing with dual-chamber pacemakers reduces atrial fibrillation in sick sinus syndrome.
abstract: BACKGROUND
  Sick sinus syndrome (SSS) is often complicated with the additional presence of atrial fibrillation (AF). Atrial septal pacing, compared with right atrial appendage (RAA) pacing, shortens the atrial conduction time and reduces the dispersion of the refractoriness. However, low atrial septal (LAS) pacing's efficacy for preventing AF in SSS remains controversial in Japan.
  
  
  RESULTS
  We analyzed 95 consecutive patients with SSS who underwent dual-chamber pacemaker implantations. Forty-two patients (44%) had a history of AF at the time of the pacemaker implantation. In the group without a history of AF, LAS pacing was performed in 17 patients, and RAA pacing in 36 patients. In the group with a history of AF, LAS pacing was performed in 15 patients, and RAA pacing in 27 patients. We evaluated whether LAS pacing prevented the development of de novo AF and the persistence of AF after pacemaker implantations. No significant differences were found in the baseline characteristics between the RAA and LAS groups regardless of an AF history. During a 1-year follow-up period, in the SSS patients without a history of AF, 19.0% (7/36) of the RAA group developed de novo AF, however, 5.9% (1/17) of the LAS group developed de novo AF (p=0.20). On the other hand, in the SSS patients with a history of AF, 22.0% (6/27) of the RAA group developed persistent AF, but none of the LAS group developed any persistent AF (p=0.049). There were no post-operative complications related to the LAS pacing.
  
  
  CONCLUSIONS
  LAS pacing is safe and feasible. LAS pacing may prevent the progression to persistent AF in SSS patients with dual-chamber pacemakers.
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita 565-0871, Japan. hminami@medone.med.osaka-u.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Minamiguchi
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Nanto
authors.forename: Toshinari
authors.initials: T
authors.lastname: Onishi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Watanabe
authors.forename: Masaaki
authors.initials: M
authors.lastname: Uematsu
authors.forename: Issei
authors.initials: I
authors.lastname: Komuro
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000150:complications* / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D018450:Disease Progression; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012804:Sick Sinus Syndrome / Q000150:complications*