Semiquantitative assessment of mitral regurgitation by Doppler color flow imaging in patients aged < 20 years.

Doppler color flow imaging is a rapid, noninvasive method to estimate the severity of mitral regurgitation (MR) in adult patients; theoretically, it should be possible to use the technique at least as successfully in infants and children, because problems with beam penetration should be diminished. Doppler color flow studies in 27 pediatric patients (age range 12 days to 17 years, median 7 months) with various degrees of MR (but without coexistent aortic regurgitation or intracardiac shunt) were analyzed. All patients underwent left ventriculography within 2 weeks of their color Doppler examination. Three sets of parameters were investigated, including: (1) maximal length of regurgitant jet: by itself, and indexed to cube root of body surface area (BSA) and to left atrial depth; (2) proximal width of jet; by itself, and indexed to cube root of BSA and to diameter of mitral annulus; and (3) regurgitant jet area (RJA): by itself, and indexed to BSA and left atrial area (LAA). Of these parameters, RJA indexed to BSA, and the ratio of RJA/LAA had the best correlation with angiographic grading (r = 0.84 and 0.92, respectively). With our instrumentation, the "cutoff" values in infants and children separating mild, moderate and severe MR appear to be 4 and 10 cm2/m2 for RJA/BSA, and 30 and 50% for RJA/LAA, respectively. Both inter- and intraobserver correlations were good for RJA (r = 0.95 and 0.94, respectively), and the ratio of RJA/LAA (r = 0.92 and 0.94, respectively). Semiquantitative assessment of MR appears to be possible in pediatric patients, using 1 instrument and a standardized technique.