Independent pulsed Doppler mapping techniques. Limitations in the prediction of the angiographic severity of mitral regurgitation.

Pulsed Doppler mapping of the flow disturbance of mitral insufficiency is commonly employed to estimate the severity of regurgitation. We re-examined the customary pulsed Doppler criterion of relative depth of jet penetration (MR ratio) in 50 patients undergoing left ventriculography and found a modest correlation (r = 0.70) between Doppler and angiographic estimates of regurgitant grade. The MR ratio did not provide statistically significant separation between adjacent angiographic grades 1+ to 3+ (scale 0 to 4+). However, when the data were re-analyzed for the subset of 36 patients with pure mitral regurgitation the correlation between Doppler and angiographic estimates of regurgitant grade improved dramatically (r = 0.88) and MR ratio provided statistically significant separation between all angiographic grades with the sole exception of the distinction between 1+ and 2+ regurgitation. The presence of restriction of the regurgitant orifice in the remaining 14 patients with relative mitral inflow obstruction may result in a nozzle effect on the regurgitant jet which alters the relationship between depth of jet penetration and severity of regurgitation. In this latter group of patients independent pulsed Doppler mapping techniques may provide inaccurate estimates of the angiographic severity of mitral regurgitation.