Vena contracta width measurement: theoretic basis and usefulness in the assessment of valvular regurgitation severity.

In patients with valvular regurgitation, the regurgitation jet can be observed by Doppler color flow imaging. Vena contracta is defined as the narrowest part of the jet, just distal to the regurgitant orifice. Vena contracta dimensions reflect the severity of regurgitation. Vena contracta diameter, usually easy to measure in clinical practice, is well correlated with the effective regurgitant orifice area and the regurgitant volume. Cutoff values have been determined to identify severe regurgitation for mitral, aortic, and tricuspid valves. In clinical practice, determination of vena contracta diameter is a useful and simple method for assessment of valvular regurgitation. In the future, assessment of complex jet regurgitations will probably benefit from the contribution of three-dimensional Doppler flow imaging, which should improve the performances of the method.