The movement of the anterior leaflet of the mitral valve has been recorded with an ultrasound echo technique. The intrinsic mobility of the valve cusps and the rate of ventricular filling are thought to influence the closure of the valve during diastole. Atrial contraction occurs at the end of ventricular diastole and reopens the valve before the mitral valve returns to the closed position before the onset of ventricular systole. The relation of the opening snap and third heart sound to the movement of the cusp is shown. In mitral stenosis ventricular systole occurs when the mitral valve is still far away from the closed position and the rapid movement of the cusp to the closed position may be the cause of the high intensity vibrations of the first heart sound. The EF slope (representing the rate of the closing movement of the cusp in end diastole) is decreased and a good correlation has been found with the degree of stenosis. After mitral valvotomy the EF slope increases significantly. The validity of these methods in assessing mitral incompetence or relative predominance of stenosis or incompetence in mixed mitral lesions is discussed. The ultrasound cardiograph is a fairly simple and completely atraumatic technique with proven diagnostic value in mitral valve disease. In addition, because of the new type of information that is given, it has potential as a research tool which is, as yet, largely unexplored.
Wharton et al. (1970) studied this question.