title: Left bundle branch-Purkinje system in patients with bundle branch reentrant tachycardia: lessons from catheter ablation and electroanatomic mapping.
abstract: BACKGROUND
  The mechanism of bundle branch reentrant tachycardia has been described, and ablation of the right bundle branch (RBB) is a curative approach.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the left bundle branch (LBB)-Purkinje system during sinus rhythm and to test the feasibility of ablating the LBB in patients with bundle branch reentrant tachycardia.
  
  
  METHODS
  Thirteen consecutive male patients (age 62 +/- 12 years) with sustained bundle branch reentrant tachycardia were included in the study.
  
  
  RESULTS
  Surface ECG before ablation showed left bundle branch block (LBBB) in 10 patients and a narrow QRS in 3 patients. Bundle branch reentrant tachycardia with LBBB morphology was inducible in all cases. Ablation of the RBB resulted in right bundle branch block (RBBB) on surface ECG in 8 of 9 patients and total AV block with preserved retrograde conduction over the LBB in 1 of 9 patients. In 4 patients with LBBB during sinus rhythm, electroanatomic mapping showed (1) absent conduction through the anterior fascicle of the LBB and (2) anterograde slow conduction through the posterior fascicle of the LBB with (3) left ventricular activation by transseptal conduction due to conduction block between the distal Purkinje and the local ventricle in 2 of 4 patients. The LBB was successfully ablated in these 4 patients. During mean follow-up of 48 +/- 29 months, 3 patients died, but bundle branch reentrant tachycardia did not recur in any patient.
  
  
  CONCLUSIONS
  In patients with LBBB and bundle branch reentrant tachycardia, anterograde slow conduction over the LBB is present. Ablation of the LBB is feasible and may be an alternative approach for bundle branch reentrant tachycardia. Patients with normal heart and bundle branch reentrant tachycardia have a good prognosis and may not require further intervention.
authors.affiliation: Asklepios Klinik St Georg, Hanseatic Heart Centre, Hamburg, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Schmidt
authors.forename: Min
authors.initials: M
authors.lastname: Tang
authors.forename: K R Julian
authors.initials: KR
authors.lastname: Chun
authors.forename: Matthias
authors.initials: M
authors.lastname: Antz
authors.forename: Roland R
authors.initials: RR
authors.lastname: Tilz
authors.forename: Andreas
authors.initials: A
authors.lastname: Metzner
authors.forename: Bulent
authors.initials: B
authors.lastname: Koektuerk
authors.forename: Ping
authors.initials: P
authors.lastname: Xie
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Kuck
authors.forename: Feifan
authors.initials: F
authors.lastname: Ouyang
mesh_terms: D000328:Adult; D000368:Aged; D018780:Body Surface Potential Mapping / Q000379:methods*; D002036:Bundle of His / Q000503:physiopathology* / Q000601:surgery; D002304:Cardiac Pacing, Artificial / Q000379:methods; D017115:Catheter Ablation / Q000379:methods*; D004554:Electric Countershock / Q000379:methods; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011690:Purkinje Fibers / Q000503:physiopathology* / Q000601:surgery; D012189:Retrospective Studies; D013318:Stroke Volume / Q000502:physiology; D054139:Tachycardia, Reciprocating / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology