Quantification of mitral and tricuspid regurgitation by the proximal flow convergence method using two-dimensional colour Doppler and colour Doppler M-mode: Influence of the mechanism of regurgitation

In patients with mitral (n=77: organic=49, functional=28) and tricuspid reg urgitation (n=55: functional=54) quantified by angiography, the temporal va riation of the proximal flow convergence region throughout systole was asse ssed by colour Doppler M-Mode, and peak and mean radius of the proximal iso velocity surface area for 28 cm/s blood flow velocity were measured. Additi onally, the peak radius derived from two-dimensional colour Doppler was obt ained. About 50% of the patients with mitral and tricuspid regurgitation sh owed a typical temporal variation of the flow convergence region related to the mechanism of regurgitation. The different proximal isovelocity surface area radii were similarly correlated to the angiographic grade in mitral a nd tricuspid regurgitation (rank correlation coefficients 0.55-0.89) and th ey differentiated mild to moderate (grade less than or equal to II) from se vere (grade greater than or equal to III) mitral and tricuspid regurgitatio n with comparable accuracy (82-96%). However, moderate mitral regurgitation due to leaflet prolapse in two patients was correctly classified by the me an M-mode radius and overestimated by both peak radii. Only half of the patients showed a typical variation of the flow convergenc e region related to the mechanism of regurgitation. The different proximal isovelocity surface area radii were suitable to quantify mitral and tricusp id regurgitation in most patients. However, in mitral regurgitation due to leaflet prolapse the use of the mean M-mode radius may avoid overestimation . (C) 1998 Elsevier Science Ireland Ltd All rights reserved.