subaortic stenosis
Pronunciation: sub-ay-OR-tik sten-OH-sis
Obstruction of left ventricular outflow occurring below the aortic valve, commonly due to fibrous membrane or muscular ridge.
Full Definition
Subaortic stenosis is a form of left ventricular outflow tract obstruction that occurs below the aortic valve level, accounting for approximately 10-20% of all left heart obstructive lesions in children. The most common form is discrete subaortic stenosis caused by a fibrous membrane or ridge that encircles the left ventricular outflow tract just below the aortic valve. Less commonly, the obstruction may be due to muscular bundles or tunnel-like narrowing. Unlike congenital aortic valve stenosis, subaortic stenosis is typically an acquired lesion that progresses over time and is often associated with aortic regurgitation due to disturbance of valve leaflet function. Treatment usually requires surgical resection of the obstructive tissue, though the lesion has a tendency to recur, necessitating long-term follow-up and potential repeat intervention.
Usage
Usage note: Distinguish from valvar and supravalvar stenosis; note progressive nature and association with aortic regurgitation.
In Context
- "Echocardiography revealed discrete subaortic stenosis with a peak gradient of 45 mmHg." — Echo report
- "Surgical resection of subaortic stenosis was performed through aortotomy approach." — Operative note