Analysis of methodology for quantifying mitral regurgitation by Doppler echocardiography

It is generally agreed that Doppler echocardiography is highly sensitive and specific for the detection of mitral regurgitation. There is more confusion about its ability to quantitate the degree of mitral regurgitation. Studies of the intensity of the Doppler signals, as well as cross sectional Doppler studies apparently can provide a straightforward, but rough estimate of the degree of regurgitation in term of atrial extent of the disturbed flow. The methods are also sensitive to methodological errors as beam direction, movement of the heart, signal/noise relationship and the size of the left atrium. Another approach to the non-invasive measurement of mitral regurgitation includes the use of Doppler echocardiography for the determination of both aortic and mitral volumetric flow. In a study of patients with mitral regurgitation, we found a close correlation between the regurgitant fraction determined by Doppler echocardiography, and the regurgitant severity determined by left ventriculography. This technique can only be used in pure mitral regurgitation, while associated atrial fibrillation, mitral stenosis, and combined aortic and mitral regurgitation make correct measurements difficult.