ABSTRACT
Definition Mitral regurgitation (MR) refers to retrograde flow through the mitral valve during ventricular systole. Among valvular heart diagnoses, it ranks second (after aortic stenosis [AS]) in prevalence (Iung et al., 2002). The severity of MR is usually scored on a 6-point scale, ranging from the physiologic levels of ‘none’ and ‘trace’ to pathologic levels 1-4. Both angiographic and echocardiographic means of quantitating regurgitant flow exist. As a noninvasive and contrast-free technique, echocardiographic assessment is the current dominant technology. The variety of subjective and objective criteria used to grade valve regurgitation is beyond the scope of this book, but may be found in echocardiography and angiography texts. When clinical management demands more precise grading of mitral regurgitation, quantitative methods based on careful 2D and Doppler echocardiographic measurements can be employed. These volumetric assessments yield descriptions of severity in terms of effective regurgitant orifice (ERO) and regurgitant stroke volume (RSV). Using this volumetric grading scheme, severe (4+) MR is defined as an ERO exceeding 40 mm2 or a regurgitant volume >60 ml/beat (Tribouilloy et al., 2002).
