TEMPORAL VARIATIONS OF MITRAL REGURGITATI ON JETS - A 4TH-DIMENSION FOR DOPPLER ASSESSMENT OF MITRAL REGURGITATION

The quantitation of mitral regurgitation is based on measurement of th e maximal jet area by colour flow mapping. Discrepancies have been rep orted with the possibility of significant temporal variations of jet s ize. The aim of this study was to determine whether evaluation could b e improved by taking these variations into consideration. Three dimens ional Doppler colour flow mapping by combining measurements of length, height and width of the jet in two orthogonal planes, in order to obt ain a global index of regurgitation, was undertaken in 40 patients wit h angiographically documented mitral regurgitation classified in three degrees, mild, moderate and severe. Two dimensional Doppler with colo ur 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 re gurgitation index). When there were significant temporal variations, t he index was calculated during each phase of systole and the values av eraged to obtain a mean global regurgitation index. Temporal variation s were observed in 14 of the 40 patients (35 %), mainly in mild and mo derate 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 sev erity 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. The mean index corrected th ese over-estimations in 10 cases, resulting in 90 % of satisfactory es timations. The correlation coefficient between the angiographic and Do ppler assessments improved from 0,79 with the maximal index to 0.93 wi th the mean index. The authors conclude that measurement of the maxima l jet regurgitation area offers a satisfactory method of assessing mit ral regurgitation by three-dimensional Doppler colour flow mapping in the absence of systolic temporal variations. This fourth dimension of assessment required averaging of the regurgitation index in systole. T he practical interest resides in the accurate identification of modera te lesions and in avoiding further, often unjustified, investigations in these patients.