OBJECTIVE We sought to evaluate the vena contracts 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 +/- 3.1 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 cm(2), 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 axial area (r = 0.46, p < 0.0001). A VCW greater than or equal to 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,vith 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. (C) 2000 by the American College of Cardiology.