title: Efficacy of low interatrial septum and right atrial appendage pacing for prevention of permanent atrial fibrillation in patients with sinus node disease: results from the electrophysiology-guided pacing site selection (EPASS) study.
abstract: BACKGROUND
  The role of pacing sites and atrial electrophysiology on the progression of atrial fibrillation (AF) to the permanent form in patients with sinus node dysfunction (SND) has never been investigated. The aim of the study was to investigate the relationship between atrial electrophysiology and the efficacy of atrial pacing at the low interatrial septum (IAS) or at the right atrial appendage (RAA) to prevent persistent/permanent AF in patients with SND.
  
  
  RESULTS
  The Electrophysiology-Guided Pacing Site Selection (EPASS) Study was a prospective, controlled, randomized study. Atrial refractoriness, basal and incremental conduction times from the RAA to the coronary sinus ostium were measured before implantation, and the difference (ΔCTos) was calculated. Patients with ΔCTos ≥ 50 ms (study group) and those with ΔCTos <50 ms (control group) were randomly assigned to RAA or IAS with algorithms for continuous atrial stimulation "on." The primary end point was time to development of permanent or persistent AF within a 2-year follow-up in the study group, IAS versus RAA. Data were analyzed by intention to treat. One hundred two patients (77 ± 7 years, 44 mol/L) were enrolled, 69 (68%) in the study group and 33 (32%) in the control group. Of these, 97 ended the study, respectively, randomly assigned: 29 IAS versus 36 RAA and 18 IAS versus 14 RAA. After a mean follow-up of 15 ± 7 (median, 17) months, 11 (16.6%) patients in the study group met the primary end point: 2 IAS versus 9 RAA (log rank=3.93, P=0.047).
  
  
  CONCLUSIONS
  In patients with SND and intra-atrial conduction delay, low IAS pacing was superior to RAA pacing in preventing progression to persistent or permanent AF.
  
  
  BACKGROUND
  URL: http://www.clinicaltrials.gov. Unique identifier: NCT00239226.
authors.affiliation: Cardiology Department, General Hospital, Camposampiero, Italy. roberto.verlato@libero.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Verlato
authors.forename: Giovanni Luca
authors.initials: GL
authors.lastname: Botto
authors.forename: Riccardo
authors.initials: R
authors.lastname: Massa
authors.forename: Claudia
authors.initials: C
authors.lastname: Amellone
authors.forename: Antonello
authors.initials: A
authors.lastname: Perucca
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Bongiorni
authors.forename: Emanuele
authors.initials: E
authors.lastname: Bertaglia
authors.forename: Vigilio
authors.initials: V
authors.lastname: Ziacchi
authors.forename: Marcello
authors.initials: M
authors.lastname: Piacenti
authors.forename: Attilio
authors.initials: A
authors.lastname: Del Rosso
authors.forename: Giovanni
authors.initials: G
authors.lastname: Russo
authors.forename: Maria Stella
authors.initials: MS
authors.lastname: Baccillieri
authors.forename: Pietro
authors.initials: P
authors.lastname: Turrini
authors.forename: Giorgio
authors.initials: G
authors.lastname: Corbucci
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020517:Atrial Appendage / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D054087:Atrial Septum / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D018450:Disease Progression; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D007558:Italy; D053208:Kaplan-Meier Estimate; D008297:Male; D018579:Patient Selection; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012032:Refractory Period, Electrophysiological; D012804:Sick Sinus Syndrome / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome