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Characterization of the infarct substrate and ventricular tachycardia circuits with noncontact unipolar mapping in a porcine model of myocardial infarction
- Source :
- Heart Rhythm. 3:189-197
- Publication Year :
- 2006
- Publisher :
- Elsevier BV, 2006.
-
Abstract
- Background Conventional mapping of ventricular tachycardia (VT) after myocardial infarction is limited in patients with hemodynamically untolerated or noninducible VT. Objectives The purpose of this study was to develop a unique strategy using noncontact unipolar mapping to define infarct substrate and VT circuits. Methods Dynamic substrate mapping (DSM) was performed in seven pigs with healed anterior myocardial infarction. This technique defined substrate as the intersection of low-voltage areas identified in sinus rhythm and during pacing around the infarct. Pacing was also performed within the substrate to determine exit sites. Results Anteroapical transmural scar was identified in all animals. A mean of three pacing sites was used for substrate definition. The mean area (± SD) was 18.4 ± 8.8 cm 2 by DSM and 15.4 ± 6.9 cm 2 by pathology ( P >.5). A mean of 4.5 sites was paced within substrate. Ten of 18 paced wavefronts exited substrate adjacent to the pacing area, seven exited at distant areas, and one had two exits. VT was induced in five animals (1.6 morphologies per animal). Except for one VT, circuit exit sites were identified at substrate borders on the endocardium. VT exit sites were at (n = 6) or near (n = 3) a pacing exit site. Electrogram voltages differed significantly between substrate, border, and nonsubstrate areas in infarcted animals and in comparison with control animals. No substrate was identified in two control animals. Conclusion DSM is a reliable method for infarct substrate localization in this model. Pacing within substrate can predict VT exit sites and may prove useful for ablation of unmappable VT after myocardial infarction.
- Subjects :
- medicine.medical_specialty
Substrate mapping
Swine
medicine.medical_treatment
Myocardial Infarction
Anterior myocardial infarction
Ventricular tachycardia
Statistics, Nonparametric
Cicatrix
Heart Conduction System
Physiology (medical)
Internal medicine
medicine
Animals
Sinus rhythm
Myocardial infarction
Endocardium
business.industry
Cardiac Pacing, Artificial
medicine.disease
Ablation
Substrate (marine biology)
Disease Models, Animal
Tachycardia, Ventricular
Cardiology
Electrophysiologic Techniques, Cardiac
Cardiology and Cardiovascular Medicine
business
Subjects
Details
- ISSN :
- 15475271
- Volume :
- 3
- Database :
- OpenAIRE
- Journal :
- Heart Rhythm
- Accession number :
- edsair.doi.dedup.....ad80d7453be864164315e2da7b9b99e6