An experimental method for the percutaneous induction of a posterolateral infarct and functional ischemic mitral regurgitation.
OBJECTIVE
Appropriate experimental models are needed to study the mechanisms underlying left ventricular (LV) remodeling and functional ischemic mitral regurgitation (IMR). Herein is described an original percutaneous method for inducing a well-defined posterolateral infarct and significant IMR.


METHODS
Under videofluoroscopic guidance, the second (OM2) and third (OM3) obtuse marginal branches of the circumflex artery of six sheep were selectively and sequentially injected with 100% ethyl alcohol. Transthoracic echocardiography (TTE) was performed before and after alcohol injection, and weekly until sacrifice at 8 +/- 1.3 weeks. The LV endsystolic (LVESD) and end-diastolic (LVEDD) dimensions, interpapillary distance (M1-M2), mitral annulus diameter (MA), and degree of IMR and ischemic tricuspid regurgitation (ITR) were measured.


RESULTS
One animal died from irreversible ventricular fibrillation. In the remaining sheep, a well-defined posterolateral infarct of 22% of the heart mass resulted, followed by 2.8 + IMR and 2.1+ ITR. The mean weight gain was 16%, and all sheep showed signs of heart failure. All echocardiographic parameters were increased: systolic MA by 29%, diastolic MA by 18%, LVEDD by 33%, LVESD by 62%, M1-M2 diastolic by 32%, M1-M2 systolic by 21%, and tethering and tenting distances by 32% and 108%, respectively.


CONCLUSIONS
The percutaneous selective injection of 100% ethyl alcohol in OM2 and OM3 resulted in a well-defined posterolateral infarct and significant IMR and ITR. Because it was a percutaneous procedure, this novel, simple and reproducible method did not require a thoracotomy. This model should facilitate the further study of LV remodeling and IMR.
Joudinaud
Thomas M
TM
The International Heart Institute of Montana Foundation at Saint Patrick Hospital and Health Sciences Center and The University of Montana, Missoula, Montana 59802, USA.
Kegel
Corrine L
CL
Gabster
Alan A
AA
Sanz
Mark L
ML
MacDonald
Alistair
A
Propp
Dan
D
Callaghan
Edward
E
Weber
Patricia A
PA
Hvass
Ulrik
U
Duran
Carlos M G
CM
D000818:Animals; D002492:Central Nervous System Depressants / Q000008:administration & dosage; D003331:Coronary Vessels; D003971:Diastole / Q000502:physiology; D004195:Disease Models, Animal; D004452:Echocardiography; D004562:Electrocardiography; D000431:Ethanol / Q000008:administration & dosage; D006333:Heart Failure / Q000503:physiopathology; D006352:Heart Ventricles / Q000473:pathology; D008943:Mitral Valve / Q000473:pathology; D008944:Mitral Valve Insufficiency / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D009203:Myocardial Infarction / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D009206:Myocardium / Q000473:pathology; D012756:Sheep; D013599:Systole / Q000502:physiology; D020257:Ventricular Remodeling / Q000502:physiology*
D002492:Central Nervous System Depressants; D000431:Ethanol