ABSTRACT
Since preliminary reports, it has been proposed that measuring the flow convergence region proximal to an orifice by Doppler mapping can provide a means of calculating regurgitant flow rate. More recently, this method was used for estimation of mitral surface area in mitral stenosis. The goal of this study was to determine the accuracy and limitations of calculating mitral surface area using this concept comparatively with two dimensional echocardiography and pressure half time methods. 55 patients with rheumatic mitral stenosis with and without moderate mitral or aortic regurgitation were studied using imaging and Doppler echocardiography. The transmitral flow rate was calculated using the hemispheric flow convergence equation. The aliasing velocity was selected to 23cm/s by adjusting the zero baseline shift. Mitral valve area was evaluated according to the continuity equation. Mitral valve area by color flow convergence region method correlated well with that by two dimensional echocardiography [r = 0,90 p = 0,005] and by pressure half time [r = 0,81 p = 0,003]. This method provides accurate measurement of mitral valve area in patients with significant mitral stenosis and is not influenced by associated mitral or aortic regurgitations