CLINICAL RESEARCH: HEART RHYTHM DISORDER
Role of Purkinje Fibers in Post-Infarction Ventricular Tachycardia
Frank Bogun, MD*,
Eric Good, DO,
Stephen Reich, MD,
Darryl Elmouchi, MD,
Petar Igic, MD,
David Tschopp, MD,
Sujoya Dey, MD,
Alan Wimmer, MD,
Krit Jongnarangsin, MD,
Hakan Oral, MD1,
Aman Chugh, MD,
Frank Pelosi, MD and
Fred Morady, MD1
University of Michigan Medical Center, Ann Arbor, Michigan.
Manuscript received June 26, 2006;
accepted July 20, 2006.
* Reprint requests and correspondence: Dr. Frank Bogun, Assistant Professor of Medicine, Division of Cardiology, University of Michigan Health System, 3119 TC, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109-0366. (Email: fbogun{at}umich.edu).
OBJECTIVES: 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  145 ms. Mapping was performed focusing on areas with Purkinje potentials.
RESULTS: A total of 11 VTs with a QRS duration 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.
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Abbreviations and Acronyms
| | LV = left ventricle/ventricular | | MI = myocardial infarction | | VT = ventricular tachycardia |
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