title: Right-sided free wall accessory pathway refractory to conventional catheter ablation: lessons from 3-dimensional electroanatomic mapping.
abstract: BACKGROUND
  the aim of this study was to delineate the electroanatomic substrates of right-sided free wall (RFW) accessory pathways (APs) that were refractory to conventional catheter ablation utilizing 3-dimensional (3-D) mapping.
  
  
  RESULTS
  eleven patients with RFW APs that failed initial conventional catheter ablation(s) by a mean of 1.9 ± 0.5 attempts were enrolled in the study. Electroanatomic mapping of the right atrium was performed during orthodromic reciprocating tachycardia in 3 patients and right ventricular pacing in 8 patients. The earliest atrial activation site, which represented the atrial insertion of the AP, was separated from the tricuspid annulus by an average of 14.3 ± 3.9 mm, and the local activation time was 27.8 ± 17.0 ms earlier than that of the corresponding annular point. One patient exhibited an AP with wide branching on the atrial side. RF ablation with an irrigated catheter successfully interrupted AP conduction in all patients without complications.
  
  
  CONCLUSIONS
  RFW APs resistant to conventional catheter ablation might be due to unique anatomic AP features such as more epicardial course at the annulus level with atrial insertion distant from the tricuspid annulus. Electroanatomic mapping is helpful to accurately localize the atrial insertion sites of these APs and facilitates catheter ablation.
authors.affiliation: Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Ming Long
authors.initials: ML
authors.lastname: Chen
authors.forename: Bing
authors.initials: B
authors.lastname: Yang
authors.forename: Wei Zhu
authors.initials: WZ
authors.lastname: Ju
authors.forename: Hong Wu
authors.initials: HW
authors.lastname: Chen
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
authors.forename: Xiao Feng
authors.initials: XF
authors.lastname: Hou
authors.forename: Fengxiang
authors.initials: F
authors.lastname: Zhang
authors.forename: Jun You
authors.initials: JY
authors.lastname: Cui
authors.forename: Chuan Huan
authors.initials: CH
authors.lastname: Zhang
authors.forename: Qi Jun
authors.initials: QJ
authors.lastname: Shan
authors.forename: Jian Gang
authors.initials: JG
authors.lastname: Zou
authors.forename: Jun Ping
authors.initials: JP
authors.lastname: Sun
authors.forename: Yu Tao
authors.initials: YT
authors.lastname: Xi
authors.forename: Jie
authors.initials: J
authors.lastname: Cheng
authors.forename: Ke Jiang
authors.initials: KJ
authors.lastname: Cao
mesh_terms: D000293:Adolescent; D000328:Adult; D016280:Atrial Function, Right / Q000502:physiology*; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D013617:Tachycardia, Supraventricular / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D014261:Tricuspid Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery