Biplane measurement of mitral valve orifice size by two-dimensional echocardiography.

We used a new method of imaging the mitral valve orifice in two planes to assess 187 cases of mitral stenosis. By ensuring that the diastolic antero-posterior diameter of the mitral valve orifice in the short-axis view was the same as that obtained in the long-axis view, imaging of the true mitral valve orifice could be confirmed in 173 cases. This objective method proved to be accurate and could eliminate observer variation noted in other methods of current usage.