TEMPORAL VARIABILITY OF VENA CONTRACTA AND JET AREAS WITH COLOR DOPPLER IN AORTIC REGURGITATION - A CHRONIC ANIMAL-MODEL STUDY

Objective. The purpose of our study was to determine the temporal vari ability of regurgitant color Doppler jet areas and the width of the co lor Doppler imaged vena contracta for evaluating the severity of aorti c regurgitation. Methods. Twenty-nine hemodynamically different states were obtained pharmacologically in 8 sheep 20 weeks after surgery to produce aortic regurgitation. Aortic regurgitation was quantified by p eak and mean regurgitant flow rates, regurgitant stroke volumes, and r egurgitant fractions determined using pulmonary and aortic electromagn etic flow probes and meters balanced against each other. The regurgita nt jet areas and the widths of color Doppler imaged. vena contracta we re measured at 4 different times during diastole to determine the temp oral variability of this parameter Results. Wizen measured at 4 differ ent temporal points ill diastole, a significant change was observed in the size of the color Doppler imaged regurgitant jet (percent of diff erence: from 31.1% to 904%; 233% +/- 245%). Simple Linear regression a nalysis between each color jet area at 4 different periods in diastole and how meter-based severity of the aortic regurgitation showed only weak correlation (0.23 < r < 0.49). In contrast, for most conditions o nly a slight change was observed in the width of the color Doppler Ima ged vena contracta during the diastolic regurgitant period (percent of difference, vena contracts: from 2.4% to 12.9%, 5.8% +/- 3.2%). In ad dition, for each period the width of the color Doppler imaged vena con tracta at the 4 different time periods In diastole correlated quite st rongly with volumetric measures of the severity of aortic regurgitatio n (0.81 < r < 0.90) and with the instantaneous flow rate for the corre sponding period (0.85 < r < 0.87). Conclusions. Color Doppler imaged v ena contracta may provide a simple, practical, and accurate method for quantifying aortic regurgitation, even when using a single frame colo r Doppler how mapping image.