Obstruction of the left ventricular outflow tract by the mitral valve due to a muscle band.

This paper details a rare cause of subaortic obstruction--a muscle band tethering the anterior leaflet of the mitral valve to the ventricular septum. Excision of this band released the leaflet and cured the obstruction. The patient also had a discrete subaortic membranous obstruction, the membrane being excised.