Functional and ischemic mitral regurgitation

Unlike organic mitral regurgitation, so-called “functional” or “secondary” mitral regurgitation (MR) is related to progressive left ventricular dilatation, remodeling, dyssinchrony or distortion involving the mitral apparatus. Thus, there is no primary valve disease and leaflets are basically normal. More in general, valvular function is impaired because of underlying chronic or acute left ventricular dysfunction. As a consequence, functional MR is typically encountered in two clinical scenarios: acute left ventricular failure and chronic cardiomyopathy. Although the possible causes vary widely, the present chapter will focus on the two most common and best studied etiologies of functional MR: chronic ischemic heart disease with left ventricular dysfunction and non-ischemic, idiopathic dilated cardiomyopathy.