title: Non-contact mapping system accurately localizes right-sided accessory pathways in type B Wolff-Parkinson-White syndrome.
abstract: OBJECTIVE
  Ablation of right-sided accessory pathways (APs) is sometimes challenging because several anatomical features of the tricuspid annulus (TA) and surrounding structures differ from those of the mitral annulus. This study investigated the electrophysiological characteristics and efficacy of a non-contact mapping (NCM) system for catheter ablation of right-sided APs.
  
  
  RESULTS
  We examined nine APs in six consecutive patients who underwent catheter ablation of right-sided APs with NCM. In Case 6, we compared NCM with contact activation mapping. Three of six patients had two APs, and one of these had previously failed ablation. We observed atrial activation during sinus rhythm or atrial pacing using a multiple-electrode array (MEA) deployed in the right atrium near the TA. Non-contact mapping identified the AP location as a peri-TA breakout point that appeared prior to or simultaneously with the delta wave onset in all APs. In Case 6 we confirmed that the peri-TA breakout identified by NCM corresponded to the earliest ventricular activation identified by contact mapping. We successfully ablated nine APs by radiofrequency (RF) energy application to the breakout sites, while one AP located just above the pole of the MEA required additional conventionally guided mapping and ablation. The mean RF duration was 189.8 ± 119.0 s. After 33.2 ± 9.4 months of follow-up, one para-hisian AP and one right lateral AP recurred, but these were successfully ablated in a second procedure using NCM.
  
  
  CONCLUSIONS
  Non-contact mapping was able to identify the location of right-sided APs accurately and quickly.
authors.affiliation: The First Department of Internal Medicine, Nara Medical University, Shijocho 840, Kashihara, Nara 634-8521, Japan. taku197699@hotmail.com
authors.forename: Taku
authors.initials: T
authors.lastname: Nishida
authors.forename: Tamio
authors.initials: T
authors.lastname: Nakajima
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Kaitani
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takitsume
authors.forename: Tsunenari
authors.initials: T
authors.lastname: Soeda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okayama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Somekawa
authors.forename: Yukiji
authors.initials: Y
authors.lastname: Takeda
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Ishigami
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kawata
authors.forename: Rika
authors.initials: R
authors.lastname: Kawakami
authors.forename: Manabu
authors.initials: M
authors.lastname: Horii
authors.forename: Shiro
authors.initials: S
authors.lastname: Uemura
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Saito
mesh_terms: D058606:Accessory Atrioventricular Bundle / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D000328:Adult; D017115:Catheter Ablation; D004562:Electrocardiography / Q000379:methods; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014261:Tricuspid Valve / Q000502:physiology; D014927:Wolff-Parkinson-White Syndrome / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D055815:Young Adult