Comparison of two-dimensional and Doppler echocardiography and intracardiac hemodynamics for quantification of mitral stenosis.

Forty-three patients with mitral stenosis (MS) were studied to assess the relation of catheter-derived pressure gradient half-time (P 1/2), mitral valve areas (calculated by the Gorlin formula and 2-dimensional echocardiography [2-D echo]) to mitral valve areas derived from Doppler pressure half-time (T 1/2) in order to establish an accurate line-drawing method in nonlinear velocity tracings and to revalidate the use of the empiric constant of 220 ms as the T 1/2 that predicts a 1.0-cm2 mitral valve area. Mitral valve area could be quantified by 2-D echo in 39 of 43 patients and by Doppler in 31 of 34 patients, for a success rate of 91%. A reliable technique for measuring Doppler T 1/2 in nonlinear Doppler velocity tracings was a "mid-diastolic" line-drawing method, validated with the "anatomic" mitral valve area by 2-D echo (r = 0.89) and with the "hemodynamic" mitral valve area by the Gorlin formula (in pure MS without regurgitation) (r = 0.95). By both Doppler T 1/2 and hemodynamic P 1/2, the use of 220 ms to predict a mitral valve area of 1.0 cm2 was validated. Each T 1/2 and P 1/2 had an exponential inverse relation to the mitral valve area by the Gorlin formula in pure MS. Doppler and 2-D echocardiographic quantification of MS are complementary. Reliable measurement of T 1/2 in nonlinear velocity tracings is achieved by a mid-diastolic line-drawing method and use of the equation 220 ms/T 1/2 = mitral valve area accurately quantifies MS.