title: Focal atrial tachycardia originating from the left atrial appendage: electrocardiographic and electrophysiologic characterization and long-term outcomes of radiofrequency ablation.
abstract: BACKGROUND
  This study sought to investigate electrophysiologic characteristics and radiofrequency ablation (RFA) in patients with focal atrial tachycardia (AT) arising from the left atrial appendage (LAA).
  
  
  METHODS
  This study included seven patients undergoing RFA with focal AT. Activation mapping was performed during tachycardia to identify an earlier activation in the left atria and the LAA. The atrial appendage angiography was performed to identify the origin in the LAA before and after RFA.
  
  
  RESULTS
  AT occurred spontaneously or was induced by isoproterenol infusion rather than programmed extrastimulation and burst atrial pacing in any patient. The tachycardia demonstrated a characteristic P-wave morphology and endocardial activation pattern. The P wave was highly positive in inferior leads in all patients. Lead V1 showed upright or biphasic (+/-) component in all patients. Lead V2-V6 showed an isoelectric component in five patients or an upright component with low amplitude (<0.1 mV) in two patients. Earliest endocardial activity occurred at the distal coronary sinus (CS) ahead of P wave in all seven patients. Mean tachycardia cycle length was 381 +/- 34 msec and the earliest endocardial activation at the successful RFA site occurred 42.3 +/- 9.6 msec before the onset of P wave. RFA was acutely successful in all seven patients. Long-term success was achieved in seven of the seven over a mean follow-up of 24 +/- 5 months.
  
  
  CONCLUSIONS
  The LAA is an uncommon site of origin for focal AT (3%). There were consistent P-wave morphology and endocardial activation associated with this type of AT. The LAA focal ablation is safe and effective. Long-term success was achieved with focal ablation in all patients.
authors: Department of Cardiology, People's Hospital, University of Peking, Peking, China.
authors: Yun-Long
authors: YL
authors: Wang
authors: Xue-Bin
authors: XB
authors: Li
authors: Xin
authors: X
authors: Quan
authors: Jin-Xin
authors: JX
authors: Ma
authors: Ping
authors: P
authors: Zhang
authors: Yuan
authors: Y
authors: Xu
authors: Hai-Cheng
authors: HC
authors: Zhang
authors: Ji-Hong
authors: JH
authors: Guo
mesh_terms: D000293:Adolescent; D000328:Adult; D020517:Atrial Appendage / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D002648:Child; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D013612:Tachycardia, Ectopic Atrial / Q000175:diagnosis* / Q000601:surgery*; D016896:Treatment Outcome