title: A novel, minimally invasive, segmental myocardial infarction with a clear healed infarct borderzone in rabbits.
abstract: Ventricular arrhythmias in the setting of a healed myocardial infarction have been studied to a much lesser degree than acute and subacute infarction, due to the pericardial scarring, which results from the traditional open-chest techniques used for myocardial infarction (MI) induction. We sought to develop a segmental MI with low perioperative mortality in the rabbit that allows optimal visualization and therefore improved study of the infarction borderzone. Rabbits underwent MI using endovascular coil occlusion of the first obtuse marginal artery. Three weeks postprocedure, we evaluated our model by echocardiography and electrophysiology studies, optical mapping of isolated hearts, and histological studies. Seventeen rabbits underwent the protocol (12 MI and 5 sham) with a 92% survival to completion of the study (11 MI and 5 sham). MI rabbits demonstrated wall motion abnormalities on echocardiography while shams did not. At electrophysiological study, two MI rabbits had inducible ventricular tachycardia and one had inducible ventricular fibrillation. Isolated hearts demonstrated no pericardial scarring with a smooth, easily identifiable infarct borderzone. Optical mapping of the borderzone region showed successful mapping of peri-infarct reentry formation, with ventricular fibrillation inducible in 11 of 11 MI hearts and 1 of 5 sham hearts. We demonstrate successful high resolution mapping in the borderzone, showing delayed conduction in this region corresponding to late deflections in the QRS on ECG. We report the successful development of a minimally invasive MI via targeted coil delivery to the obtuse marginal artery with an exceptionally high rate of procedural survival and an arrhythmogenic phenotype. This model mimics human post-MI on echocardiography, gross pathology, histology, and electrophysiology.
authors.affiliation: Cardiovascular Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, USA.
authors.forename: Ohad
authors.initials: O
authors.lastname: Ziv
authors.forename: Lorraine
authors.initials: L
authors.lastname: Schofield
authors.forename: Emily
authors.initials: E
authors.lastname: Lau
authors.forename: Lenny
authors.initials: L
authors.lastname: Chaves
authors.forename: Divyang
authors.initials: D
authors.lastname: Patel
authors.forename: Paul
authors.initials: P
authors.lastname: Jeng
authors.forename: Xuwen
authors.initials: X
authors.lastname: Peng
authors.forename: Bum-Rak
authors.initials: BR
authors.lastname: Choi
authors.forename: Gideon
authors.initials: G
authors.lastname: Koren
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000453:epidemiology / Q000503:physiopathology*; D004195:Disease Models, Animal; D004452:Echocardiography; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D004617:Embolism / Q000150:complications; D015994:Incidence; D008297:Male; D009203:Myocardial Infarction / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D009206:Myocardium / Q000473:pathology*; D011817:Rabbits