This review describes numerous pathologic entities that cause structural abnormalities of the mitral valve. Different pathologic entities involve different components of the so-called mitral apparatus: atrial wall, annulus, leaflets, chordae, papillary muscles, and/or left ventricular free wall. These abnormalities can cause valvular stenosis, regurgitation, or both.
Currently, in addition to open-chest surgery to replace or repair the damaged mitral valve, there are less invasive percutaneous approaches to address mitral valve dysfunction. These include narrowing the orifice, clipping the leaflets, and inserting bioprostheses percutaneously. Understanding the structural abnormalities discussed in this review is essential for choosing the optimal therapeutic intervention for mitral valve disease.