Stenosis means constriction or narrowing. Subaortic means below the aorta. Subaortic stenosis refers to a narrowing of the left ventricle (a main chamber of the heart) just below the aortic valve. The aortic valve is the valve that blood passes through to go into the aorta, which is the main artery of the body. A stenosis limits the flow of blood out of the left ventricle.
Subaortic stenosis is a condition that may be congenital (present from birth) or may be due to a particular form of cardiomyopathy (a chronic disease of the heart) known as "idiopathic hypertrophic subaortic stenosis" (IHSS). With IHSS, the left ventricle of the heart is hypertrophied (enlarged) and the size of the cavity is smaller than it should be.
There is no known cause for subaortic stenosis, but it may occur in children who have other birth defects of the heart. It does not appear to be genetic, but may be more likely to appear in a baby who has a sibling with the same condition.
Treatment for subaortic stenosis depends on the cause and the severity of the narrowing. Treatment can include drugs or surgery. You may have to limit the exercise activities of your child. Check with your pediatric cardiologist about limiting some kinds of exercise for your child.
People with subaortic stenosis, before and after treatment, are at risk for getting an infection within the aorta or the heart valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.