How can echocardiography be used to estimate the severity of mitral regurgitation?

1. Identify the cause of the regurgitation (the most reliable method). For example, flail leaflet invariably suggests severe regurgitation, while mitral annular calcification suggests mild to moderate regurgitation.
2. Estimate the size of the jet at the level of the valve orifice using 2DE. This estimation correlates with the area of the regurgitant orifice and is a highly qualitative assessment.
3. Measure the jet size at the regurgitant orifice using color flow Doppler. This technique is not reliable because it depends on many variables other than the regurgitant volume, including left atrial size and pressure, left ventricular function, and Doppler gain settings.
4. Identify the direction of the jet using color flow Doppler. This exercise helps determine the cause of the regurgitation. For example, an eccentric jet is almost always seen when there is a flail or prolapsing leaflet, while a central jet is seen predominantly with mitral annular calcification.
5. Evaluate the associated findings. Associated findings, such as left atrial enlargement and pulmonary hypertension, signify longstanding severe mitral regurgitation.
6. Identify reversal of pulmonary venous flow during systole. This finding suggests significant mitral regurgitation.

CARDS
Cause
Associations
Reversal of pulmonary vein flow
Direction of jet
Size of jet using 2DE and color flow