On the Interrelationship Between Left Ventricle Infarction Geometry and Ischemic Mitral Regurgitation Grade.

Ischemic mitral regurgitation (IMR) is manifested by the inability of the mitral valve (MV) to form a completed sealed shape, which is induced by rapidly impairing contractile function of acute myocardial infarction (MI). Mitral valve repair with undersized ring annuloplasty is currently the preferred treatment strategy for IMR. However, the overall persistence and recurrence rate of moderate or severe IMR within 12 months of surgery has been consistently reported as high, which is a direct consequence of adverse left ventricle (LV) remodeling after MI. In this study, we developed a detailed finite element model with coupled left ventricle-mitral valve structure including mitral valve leaflets, chordae tendineae (CT), papillary muscles, and myocardium. In addition, this model was consisted of high fidelity structure segmented from image data, a novel structural constitutive model of MV leaflets and mechanical properties of CT measured using an in-vitro mechanical testing in an integrated computational modeling framework. Discrepancy of strain mapping has been found between in-silico model and in-vivo strain analysis and including pre-strain of mitral valve leaflets in in-silico model was necessary to have more agreement with in-vivo data. Our findings suggests our LV-MV model is capable of predicting IMR results by shutting down regional contractility and pre-strain should be incorporated into future LV-MV model for more accuracy.