title: Role of Purkinje fibers in post-infarction ventricular tachycardia.
abstract: OBJECTIVE
  The objective of this study was to assess the role of Purkinje fibers in monomorphic, post-infarction ventricular tachycardia (VT).
  
  
  BACKGROUND
  Ventricular fibrillation and polymorphic VT in the setting of acute myocardial infarction (MI) may be triggered by ectopy arising from Purkinje fibers.
  
  
  METHODS
  From among a group of 81 consecutive patients with post-infarction monomorphic VT referred for catheter ablation, 9 patients were identified in whom the clinical VT had a QRS duration < or =145 ms. Mapping was performed focusing on areas with Purkinje potentials.
  
  
  RESULTS
  A total of 11 VTs with a QRS duration < or =145 ms were induced and mapped in the 9 patients; 9 of the 11 VTs had a right bundle branch block/left-axis morphology that mimicked left posterior fascicular VT. The mean VT cycle length was 402 +/- 82 ms. Eight of 9 patients had a history of inferior MI involving the left ventricular septum. One patient had an anterior wall MI with septal involvement. Mapping during VT demonstrated re-entry involving the inferior left ventricular wall. In each of the VTs, a Purkinje potential was present at the exit site of the VT re-entry circuit. Single radiofrequency catheter ablation lesions were successful in eliminating these VTs in all patients.
  
  
  CONCLUSIONS
  The Purkinje system may be part of the re-entry circuit in patients with post-infarction monomorphic VT, resulting in a type of VT with a relatively narrow QRS complex that mimics fascicular VT.
authors.affiliation: University of Michigan Medical Center, Ann Arbor, Michigan, USA. fbogun@umich.edu
authors.forename: Frank
authors.initials: F
authors.lastname: Bogun
authors.forename: Eric
authors.initials: E
authors.lastname: Good
authors.forename: Stephen
authors.initials: S
authors.lastname: Reich
authors.forename: Darryl
authors.initials: D
authors.lastname: Elmouchi
authors.forename: Petar
authors.initials: P
authors.lastname: Igic
authors.forename: David
authors.initials: D
authors.lastname: Tschopp
authors.forename: Sujoya
authors.initials: S
authors.lastname: Dey
authors.forename: Alan
authors.initials: A
authors.lastname: Wimmer
authors.forename: Krit
authors.initials: K
authors.lastname: Jongnarangsin
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
authors.forename: Aman
authors.initials: A
authors.lastname: Chugh
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
mesh_terms: D000368:Aged; D018780:Body Surface Potential Mapping; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications*; D011690:Purkinje Fibers / Q000503:physiopathology*; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000503:physiopathology*