Quantification of tricuspid regurgitation by measuring the width of the vena contracta with Doppler color flow imaging: a clinical study.

OBJECTIVE: We sought to evaluate the vena contracta width (VCW) measured using color Doppler as an index of severity of tricuspid regurgitation (TR).
BACKGROUND: The VCW is a reliable measure of mitral and aortic regurgitation, but its value in measuring TR is uncertain.
METHODS: In 71 consecutive patients with TR, the VCW was prospectively measured using color Doppler and compared with the results of the flow convergence method and hepatic venous flow, and its diagnostic value for severe TR was assessed.
RESULTS: The VCW was 6.1+/-3.4 mm and was significantly higher in patients with, than those without, severe TR (9.6+/-2.9 vs. 4.2 +/- 1.6 mm, p<0.0001). The VCW correlated well with the effective regurgitant orifice (ERO) by the flow convergence method (r = 0.90, SEE = 0.17 cm2, p<0.0001), even when restricted to patients with eccentric jets (r = 0.93, p < 0.0001). The VCW also showed significant correlations with hepatic venous flow (r = 0.79, p < 0.0001), regurgitant volume (r = 0.77, p<0.0001) and right atrial area (r = 0.46, p< 0.0001). A VCW > or =6.5 mm identified severe TR with 88.5% sensitivity and 93.3% specificity. In comparison with jet area or jet/right atrial area ratio, the VCW showed better correlations with ERO (both p<0.01) and a larger area under the receiver operating characteristic curve (0.98 vs. 0.88 and 0.85, both p<0.02) for the diagnosis of severe TR.
CONCLUSIONS: The VCW measured by color Doppler correlates closely with severity of TR. This quantitative method is simple, provides a high diagnostic value (superior to that of jet size) for severe TR and represents a useful tool for comprehensive, noninvasive quantitation of TR.