Degenerative Mitral Regurgitation

Abstract

Degenerative mitral valve disease consists of a spectrum, with the mildest form recognized as fibroelastic deficiency and the most severe form as Barlow’s disease. Both forms, through different mechanisms, result in thickened leaflet segments that prolapse and billow resulting in mitral regurgitation. These disease processes also lead to changes in mitral annular shape and function. Management of these diseases will differ depending on the extent of valve involvement. Most surgeons can surgically correct mild disease affecting a single P2 segment whereas complex disease affecting both the anterior and posterior leaflets or multiple segments requires an expert mitral valve surgeon. Three-dimensional echocardiography helps determine the location and extent of the lesion. Parametric models are color-encoded topographic displays of mitral valve anatomy from three-dimensional echocardiographic images. These models improve assessment of valve anatomy and provide quantitative measurements that can be used to determine the etiology of the valve abnormality and can therefore be used to direct treatment. Three-dimensional echocardiography also improves quantification of mitral regurgitation severity. This is especially true for degenerative mitral valve disease where the regurgitant orifice is frequently eccentric resulting in an eccentric regurgitant jet. This is achieved by improving the calculation of the effective regurgitant orifice area with vena contracta area or proximal isovelocity surface area, and/or by measuring the true 3D anatomical regurgitant orifice area. Overall, three-dimensional echocardiography improves diagnosis and management of patients with degenerative mitral valve disease.