title: A swine model of infarct-related reentrant ventricular tachycardia: Electroanatomic, magnetic resonance, and histopathological characterization.
abstract: BACKGROUND
  Human ventricular tachycardia (VT) after myocardial infarction usually occurs because of subendocardial reentrant circuits originating in scar tissue that borders surviving myocardial bundles. Several preclinical large animal models have been used to further study postinfarct reentrant VT, but with varied experimental methodologies and limited evaluation of the underlying substrate or induced arrhythmia mechanism.
  
  
  OBJECTIVE
  We aimed to develop and characterize a swine model of scar-related reentrant VT.
  
  
  METHODS
  Thirty-five Yorkshire swine underwent 180-minute occlusion of the left anterior descending coronary artery. Thirty-one animals (89%) survived the 6-8-week survival period. These animals underwent cardiac magnetic resonance imaging followed by electrophysiology study, detailed electroanatomic mapping, and histopathological analysis.
  
  
  RESULTS
  Left ventricular (LV) ejection fraction measured using CMR imaging was 36% ± 6.6% with anteroseptal wall motion abnormality and late gadolinium enhancement across 12.5% ± 4.1% of the LV surface area. Low voltage measured using endocardial electroanatomic mapping encompassed 11.1% ± 3.5% of the LV surface area (bipolar voltage ≤1.5 mV) with anterior, anteroseptal, and anterolateral involvement. Reentrant circuits mapped were largely determined by functional rather than fix anatomical barriers, consistent with "pseudo-block" due to anisotropic conduction. Sustained monomorphic VT was induced in 28 of 31 swine (90%) (67 VTs; 2.4 ± 1.1; range 1-4) and characterized as reentry. VT circuits were subendocardial, with an arrhythmogenic substrate characterized by transmural anterior scar with varying degrees of fibrosis and myocardial fiber disarray on the septal and lateral borders.
  
  
  CONCLUSIONS
  This is a well-characterized swine model of scar-related subendocardial reentrant VT. This model can serve as the basis for further investigation in the physiology and therapeutics of humanlike postinfarction reentrant VT.
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Cardiovascular Division, Department of Medicine.
authors.forename: Cory M
authors.initials: CM
authors.lastname: Tschabrunn
authors.affiliation: Cardiovascular Division, Department of Medicine.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Roujol
authors.affiliation: Cardiovascular Division, Department of Medicine.
authors.forename: Reza
authors.initials: R
authors.lastname: Nezafat
authors.affiliation: Surgical Pathology Division, Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
authors.forename: Beverly
authors.initials: B
authors.lastname: Faulkner-Jones
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Cardiovascular Division, Department of Medicine.
authors.forename: Alfred E
authors.initials: AE
authors.lastname: Buxton
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Cardiovascular Division, Department of Medicine.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Josephson
authors.affiliation: Harvard-Thorndike Electrophysiology Institute, Cardiovascular Division, Department of Medicine. Electronic address: eanter@bidmc.harvard.edu.
authors.forename: Elad
authors.initials: E
authors.lastname: Anter
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000379:methods; D002921:Cicatrix / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D022062:Electrophysiologic Techniques, Cardiac; D004699:Endocardium / Q000473:pathology*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods; D009203:Myocardial Infarction / Q000150:complications*; D009206:Myocardium / Q000473:pathology*; D013318:Stroke Volume; D013552:Swine; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control
keywords: Ablation; Mapping; Myocardial infarction; Ventricular tachycardia