[Quantitative assessment of pulmonary regurgitation by two-dimensional Doppler color flow imaging: postoperative evaluation of patients with tetralogy of Fallot].

Pulmonary regurgitation (PR) is a serious event following surgical repair for tetralogy of Fallot. For quantitative assessments of PR using noninvasive methods, we performed Doppler color flow imaging in 38 children, whose ages ranged from three to 15 years. All images were obtained from one to 10 years after surgery. The right ventricle and pulmonary valve were demonstrated in the parasternal short-axis view. The images of PR flow were in red and were frozen when the area of a signal was maximum (early to mid diastole). The PR distance index (PRDI), which is the maximum PR flow distance divided by square root of the body surface area, was measured. The PR area index (the maximum PR flow area/body surface area) (PRAI) was also calculated using a track ball. Cardiac catheterization was performed for 12 patients without residual L-R shunts or any apparent tricuspid regurgitation. PR was graded (0 = absent, 1 = trivial, 2 = mild, 3 = moderate, 4 = severe) according to the projection of contrast medium in the right ventricle as seen on the main pulmonary arteriogram. The size of the right ventricle was expressed as the right ventricular end-diastolic volume (RVEDV; % of normal), as determined from the cineangiogram, and the tricuspid valve annulus diameter (TVD; % of normal) from a four-chamber view of the two-dimensional echocardiogram. There were significant differences between the PRDI and the PRAI of five patients with PR of grades 1-2 and those of seven patients with PR of grade 3-4 (p less than 0.01, p less than 0.01, respectively). There was significant correlation between the % RVEDV and the % TVD observed (r = 0.82, p less than 0.01). Significant negative correlations were observed between the PRDI and right ventricular ejection fraction (RVEF), and the PRAI and RVEF (r = -0.68, p less than 0.02; r = -0.82, p less than 0.01, respectively). RVEF was below normal in all seven patients (100%) with PR of grade 3 or more and in one of five patients (20%) with PR of grade 2 or less. The PRDI of 2.5 or more, or the PRAI of 4.0 or more was equivalent to a PR of grade 3 or more and was a reliable index of significant PR.(ABSTRACT TRUNCATED AT 400 WORDS)