Role of Purkinje fibers in post-infarction ventricular tachycardia.
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.
Bogun
Frank
F
University of Michigan Medical Center, Ann Arbor, Michigan, USA. fbogun@umich.edu
Good
Eric
E
Reich
Stephen
S
Elmouchi
Darryl
D
Igic
Petar
P
Tschopp
David
D
Dey
Sujoya
S
Wimmer
Alan
A
Jongnarangsin
Krit
K
Oral
Hakan
H
Chugh
Aman
A
Pelosi
Frank
F
Morady
Fred
F
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*