[How reliable is echocardiography in evaluating the severity of mitral stenosis]

40 patients with mitral stenosis were examined by M-mode and 2-dimensional echocardiography. E-F slope, mitral valve closure index and mitral valve area were compared with the invasively determined mitral valve area. E-F slope and closure index correlated with the valve area by an r of 0.65 and 0.62 respectively. The mitral valve area as calculated by 2D echocardiogram showed a correlation with the invasively determined valve area of 0.86 and was even better in patients with sinus rhythm (0.91). However, in severe mitral stenosis (less than 1 cm2) this correlation was only 0.62 by estimating 22% of patients with severe mitral stenosis as only moderate (greater than 1 cm2). It is concluded that whereas E-F slope and closure index are not of use in the quantification mitral stenosis, determination of mitral valve areas by 2D echo is reliable. However, in the severe mitral stenosis group 22% of mitral valve areas were estimated purely numerically by 2D echo as moderate (greater than 1 cm2).