Time changes of mitral regurgitant jets: a 4th dimension for Doppler evaluation of the severity of mitral regurgitation]

The quantitation of mitral regurgitation is based on measurement of the maximal jet area by colour flow mapping. Discrepancies have been reported with the possibility of significant temporal variations of jet size. The aim of this study was to determine whether evaluation could be improved by taking these variations into consideration. Three dimensional Doppler colour flow mapping by combining measurements of length, height and width of the jet in two orthogonal planes, in order to obtain a global index of regurgitation, was undertaken in 40 patients with angiographically documented mitral regurgitation classified in three degrees, mild, moderate and severe. Two-dimensional Doppler with colour M-mode was performed in each patient analysing early, mild and late systole. In the absence of significant temporal variation, assessment was based on measurement of maximal jet area alone (maximum global regurgitation index). When there were significant temporal variations, the index was calculated during each phase of systole and the values averaged to obtain a mean global regurgitation index. Temporal variations were observed in 14 of the 40 patients (35%), mainly in mild and moderate regurgitation. Significant differences were noted in the values of maximal (p < 0.01 to 0.001) and mean global regurgitation indices (p < 0.001 to 0.0001) between each degree of severity. A paired study demonstrated significant differences between the two indices in mild (p < 0.01) and moderate regurgitation (p < 0.05). Assessment of the severity of mitral regurgitation was satisfactory in 65% of cases using the maximal global regurgitation index with 14 overestimations, all in cases of mild and moderate regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)