Rheumatic mitral stenosis in parasternal short axis viewParasternal short axis view showing mitral valve in cross section (dotted outline). The valve leaflets are thickened and the commissures are fused. The cut is slightly oblique as a good cut should appear circular. It is often difficult to get a good circular outline of the mitral valve to varying anatomical features of the chambers and cardiac position. Ideally the smallest full circle should be taken to planimeter the valve area. If it is not a full circle, the subvalvar pathology may be measured as the valve orifice. If the smallest full circle is not taken, it will be the valve proximal to the severest stenosis (valve belly). The mitral valve cross section in mitral stenosis has a fish mouth appearance. The left ventricular cavity surrounds the mitral orifice, which in turn is surrounded by the left ventricular wall. Interventricular septum with the right ventricle beyond is seen towards the upper left corner.