title: Characteristics of the cavotricuspid isthmus in predicting recurrent conduction in the long-term follow-up.
abstract: BACKGROUND
  The characteristics of cavotricuspid isthmus (CTI) in patients with atrial fibrillation (AF) and flutter that may predict recurrence of flutter is not known. We aimed to investigate the CTI characteristics in patients who underwent a second ablation procedure for recurrent AF after previous combined pulmonary vein (PV) and CTI ablation.
  
  
  METHODS
  Among 196 consecutive patients with drug-refractory symptomatic AF who underwent PV isolation and CTI ablation with bidirectional isthmus block, 49 patients (age 50 +/- 12 years, 43 males) had recurrent AF and received a second procedure 291 +/- 241 days after the first procedure. Right atrial angiography for the evaluation of the CTI morphology, and the biatrial contact bipolar electrograms were obtained before both procedures.
  
  
  RESULTS
  In the second procedure, 11 (group 1) of the 49 patients demonstrated recovered CTI conduction. Compared with the patients without CTI conduction (group 2, n = 38), group 1 patients had a higher frequency of a pouch-type anatomy (82% vs 13%, P < 0.001), longer CTI (34.0 +/- 8.6 vs 25.5 +/- 7.5 mm, P = 0.01), longer ablation time, and larger number of radiofrequency applications; furthermore, the preablation bipolar voltage decreased along both the CTI and ablation line in group 2, whereas it remained similar in group 1 in the second procedure.
  
  
  CONCLUSIONS
  A high (22%) percentage of CTIs exhibited recurrent conduction in the long-term follow-up. The CTIs with recurrent conduction had a higher incidence of a pouch and longer length compared with those without recurrent conduction.
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Lo
authors.forename: Ching-Tai
authors.initials: CT
authors.lastname: Tai
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.forename: Shih-Lin
authors.initials: SL
authors.lastname: Chang
authors.forename: Wanwarang
authors.initials: W
authors.lastname: Wongcharoen
authors.forename: Ta-Chuan
authors.initials: TC
authors.lastname: Tuan
authors.forename: Ameya R
authors.initials: AR
authors.lastname: Udyavar
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Hu
authors.forename: Kuo-Chang
authors.initials: KC
authors.lastname: Ueng
authors.forename: Wen-Chin
authors.initials: WC
authors.lastname: Tsai
authors.forename: Chien-Jung
authors.initials: CJ
authors.lastname: Chang
authors.forename: Hsuan-Ming
authors.initials: HM
authors.lastname: Tsao
authors.forename: Satoshi
authors.initials: S
authors.lastname: Higa
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012008:Recurrence; D014261:Tricuspid Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055815:Young Adult