There are three types of subaortic stenosis. A fibrous ring - this is a discrete fibrous membrane below the valve. It may extend onto the mitral leaflet and may attach to the aortic cusps. Ultimately this could lead to heart failure. Symptoms are shortness of breath, swelling in the legs, fatigue and difficulty lying flat.
Treatment is usually surgical.
During surgery a portion of the muscle of the heart and the membrane are excised to relieve the obstruction. Recurrence of the obstruction can occur and may require repeat surgery. Follow-up usually consists of yearly echocardiograms. Medical treatment varies from case to case and depends on the condition of the heart muscle and associated medical problems. Katz NM, et al.