Seventeen patients (12 with native and five with prosthetic tricuspid valves) with tricuspid stenosis were studied by Doppler echocardiography followed by cardiac catheterization within 24 h. The mean tricuspid diastolic pressure gradient was calculated using the modified Bernoulli equation. Tricuspid valve area (TVA) was calculated by the pressure half-time method (TVA = 190 divided by pressure half-time). Data from Doppler echocardiography and cardiac catheterization were compared. The Doppler-derived tricuspid mean diastolic gradient was 1.9-9.9 mmHg (average 5.3 +/- 2.5 mmHg), which correlated moderately well with the catheterization-determined mean diastolic gradient of 2-17 mmHg (average 7.3 +/- 4.0 mmHg), R = 0.74, standard error of the estimate (SEE) 1.70 mmHg, Y = 0.45 x + 2.00, P less than 0.001. The Doppler-derived TVA was 0.56-1.58 cm2 (average 1.06 +/- 0.32 cm2), which correlated well with the catheterization-determined TVA of 0.4-2.2 cm2 (average 1.06 +/- 0.46 cm2), R = 0.81, SEE = 0.20 cm2, Y = 0.56 x + 0.46, P less than 0.001. Of 12 patients undergoing right ventricular angiography, the angiographic and Doppler grades of tricuspid regurgitation matched exactly in six and differed by one grade in the remaining six. This study demonstrated that Doppler echocardiography compares very well to cardiac catheterization in the quantification of tricuspid stenosis and in the assessment of concomitant tricuspid regurgitation.