Cystic subaortic discrete membrane in an elderly woman.

A discrete subaortic membrane is an uncommon cause of left ventricular outflow tract (LVOT) obstruction in patients of advanced age. Here, a significant LVOT obstruction caused by a discrete membrane is reported in a 64-year-old woman. On echocardiographic examination the membrane had a cystic appearance. To the present authors' knowledge, this is the first reported case of a cystic subaortic membrane.