Mitral valve function following ischemic cardiomyopathy: A biomechanical perspective

Ischemic mitral valve (MV) is a common complication of pathologic remodeling of the left ventricle due to acute and chronic coronary artery diseases. It frequently represents the pathologic consequences of increased tethering forces and reduced coaptation of the MV leaflets. Ischemic MV function has been investigated from a biomechanical perspective using finite element-based computational MV evaluation techniques. A virtual 3D MV model was created utilizing 3D echocardiographic data in a patient with normal MV. Two types of ischemic MVs containing asymmetric medial-dominant or symmetric leaflet tenting were modeled by altering the configuration of the normal papillary muscle (PM) locations. Computational simulations of MV function were performed using dynamic finite element methods, and biomechanical information across the MV apparatus was evaluated. The ischemic MV with medial-dominant leaflet tenting demonstrated distinct large stress distributions in the posteromedial commissural region due to the medial PM displacement toward the apical-medial direction resulting in a lack of leaflet coaptation. In the ischemic MV with balanced leaflet tenting, mitral incompetency with incomplete leaflet coaptation was clearly identified all around the paracommissural regions. This computational MV evaluation strategy has the potential for improving diagnosis of ischemic mitral regurgitation and treatment of ischemic MVs.