The severity of mitral regurgitation can be assessed by echo-Doppler qualitatively and quantitatively. The width of the regurgitant jet at its narrowest point, vena contracta, is a qualitative method to assess the severity of mitral regurgitation, which roughly correlates with the size of the regurgitant orifice. Advanced Doppler principles can provide us with more quantitative measures of regurgitant volume and regurgitant orifice.