ABSTRACT
Mitral regurgitation is a very complex disease and has been poorly understood in the past. Unlike mitral stenosis, for which the cause is almost always rheumatic disease resulting in predictable mitral valve lesions, there are many disease processes that may render a mitral valve incompetent (Table 4.1).1 With the eradication of rheumatic disease in most parts of the world, degenerative valve disease, bacterial and non-bacterial endocarditis, congenital heart disease, and diseases of the left ventricle including ischemia and cardiomyopathy, are increasingly implicated as the cause of mitral regurgitation. In addition, each disease process may cause a variety of mitral lesions that can singly or in combination adversely affect the structural integrity of the mitral valve apparatus.
