title: Electrophysiologic and electrocardiographic characteristics and radiofrequency catheter ablation of focal atrial tachycardia originating from the left atrial appendage.
abstract: BACKGROUND
  The left atrial appendage (LAA) is one of the major sources of focal atrial tachycardias (ATs).
  
  
  OBJECTIVE
  The purpose of this study was to investigate the detailed electrophysiologic characteristics and catheter ablation of focal ATs originating from the LAA.
  
  
  METHODS
  The study population consisted of 47 consecutive patients with 50 focal ATs originating from the left atrium (LA): LAA in 13, left pulmonary veins (PVs) in 14, right PVs in 12, and mitral annulus in 11. Programmed electrical stimulation and pharmacologic testing were performed to examine the mechanism of LAA AT. Left atriography was performed prior to radiofrequency ablation to identify the focus in the LAA.
  
  
  RESULTS
  The mechanism of LAA AT was automaticity in 11 and triggered activity in 2. The 13 LAA foci were located mainly at the LAA base: 11 on the medial side and 2 on the lateral side. Atrial activation sequences within the distal coronary sinus were helpful in differentiating these LAA foci. The criterion of a negative P wave in leads I and aVL indicating an LAA AT focus was associated with sensitivity of 92.3%, specificity 97.3%, positive predictive value 92.3%, and negative predictive value 97.3%. No complications occurred in any of the 13 patients. All 13 patients were free of atrial arrhythmias without any antiarrhythmic drugs during follow-up of 8 +/- 3 years.
  
  
  CONCLUSIONS
  LAA ATs have typical electrophysiologic and electrocardiographic characteristics that are helpful in guiding radiofrequency catheter ablation.
authors: Cardiac Rhythm Management Laboratory, Division of Cardiovascular Diseases, University of Alabama at Birmingham, 1670 University Boulevard, 1530 Third Avenue S., Birmingham, AL 35294, USA. takumi-y@fb4.so-net.ne.jp
authors: Takumi
authors: T
authors: Yamada
authors: Yoshimasa
authors: Y
authors: Murakami
authors: Yukihiko
authors: Y
authors: Yoshida
authors: Taro
authors: T
authors: Okada
authors: Naoki
authors: N
authors: Yoshida
authors: Junji
authors: J
authors: Toyama
authors: Naoya
authors: N
authors: Tsuboi
authors: Yasuya
authors: Y
authors: Inden
authors: Makoto
authors: M
authors: Hirai
authors: Toyoaki
authors: T
authors: Murohara
authors: Hugh T
authors: HT
authors: McElderry
authors: Andrew E
authors: AE
authors: Epstein
authors: Vance J
authors: VJ
authors: Plumb
authors: G Neal
authors: GN
authors: Kay
mesh_terms: D000328:Adult; D020517:Atrial Appendage / Q000503:physiopathology* / Q000601:surgery; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted