title: Focal atrial tachycardia: new insight from noncontact mapping and catheter ablation.
abstract: BACKGROUND
  This study investigated the electrophysiologic characteristics, atrial activation pattern, and effects of radiofrequency (RF) catheter ablation guided by noncontact mapping system in patients with focal atrial tachycardia (AT).
  
  
  RESULTS
  In 13 patients with 14 focal ATs, noncontact mapping system was used to map and guide ablation of AT. AT origins were in the crista terminalis (n=8), right atrial (RA) free wall (n=3), Koch triangle (n=1), anterior portion of RA-inferior vena cava junction (n=1), and superior portion of tricuspid annulus (n=1); breakout sites were in the crista terminalis (n=5), RA free wall (n=5), middle cavotricuspid isthmus (n=2), and RA-superior vena cava junction (n=2). ATs arose from the focal origins (11 ATs inside or at the border of low-voltage zone), with preferential conduction, breakout, and spread to the whole atrium. After applications of RF energy on the earliest activation site or the proximal portion of preferential conduction from AT origin, 13 ATs were eliminated without complication. During the follow-up period (8+/-5 months), 11 (91.7%) of the 12 patients with successful ablation were free of focal ATs.
  
  
  CONCLUSIONS
  Focal AT originates from a small area and spreads out to the whole atrium through a preferential conduction. Application of RF energy guided by noncontact mapping system was effective and safe in eliminating focal AT.
authors.affiliation: Division of Cardiology, Department of Medicine, National Yang-Ming, University School of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Higa
authors.forename: Ching-Tai
authors.initials: CT
authors.lastname: Tai
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.forename: Tu-Ying
authors.initials: TY
authors.lastname: Liu
authors.forename: Pi-Chang
authors.initials: PC
authors.lastname: Lee
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Huang
authors.forename: Ming-Hsiung
authors.initials: MH
authors.lastname: Hsieh
authors.forename: Yoga
authors.initials: Y
authors.lastname: Yuniadi
authors.forename: Bien-Hsien
authors.initials: BH
authors.lastname: Huang
authors.forename: Shih-Huang
authors.initials: SH
authors.lastname: Lee
authors.forename: Kwo-Chang
authors.initials: KC
authors.lastname: Ueng
authors.forename: Yu-An
authors.initials: YA
authors.lastname: Ding
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D000241:Adenosine / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D017115:Catheter Ablation; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D013612:Tachycardia, Ectopic Atrial / Q000188:drug therapy / Q000503:physiopathology* / Q000601:surgery*
chemical_list: D000889:Anti-Arrhythmia Agents; D000241:Adenosine