Mitral stenosis on M-mode echocardiography

The top tracing shows a normal anterior mitral leaflet (AL), showing early opening (E) due to passive left ventricle filling and the late leaflet opening due to atrial contraction (A). The bottom tracing is from a patient with mitral stenosis. In contrast to the normal valve, the stenotic valve is thicker, as indicated by the multiple lines rather than a single one; it never closes during diastole and the slope of closure (E to F slope) is reduced with a velocity of 20 mm/sec; and the posterior leaflet (PL) moves in parallel to the anterior rather than independently. In this patient, the A wave is lost because of atrial fibrillation.