Mitral valve anomalies obstructing left ventricular outflow.

This paper reports on two cases of more uncommon types of subaortic stenosis. A 2-year-old boy was found with accessory mitral valve leaflet (AMVL) attaching to the anterior leaflet, ballooning into the subaortic ventricular septum associated with a discrete subaortic membrane. The obstruction was successfully relieved by removal of the AMVL and resection of the membrane. A 19-day-old newborn with accessory tissue on the mitral valve (AMVT) causing subaortic stenosis, subaortic ventricular septal defect (VSD) and patent ductus arteriosus was operated on successfully. Accessory tissue excision through the VSD, VSD patch closure and ductus ligation were performed.