Prenatal Diagnosis: Fetal diagnosis of aortic stenosis is made by an echocardiogram of the baby's heart and can be made as early as 16 weeks into the pregnancy. An echocardiogram of the heart is done when a possible problem is identified during a routine prenatal ultrasound or because of a family history of congenital heart disease. The Fetal Diagnosis and Treatment Center offers comprehensive fetal diagnosis and treatment alternatives for unborn babies with aortic stenosis.

Symptoms: Symptoms of aortic stenosis are related to the degree of narrowing, leakage, and the presence of other heart problems. Mild aortic stenosis usually does not cause heart-related symptoms. More severe aortic stenosis may cause chest pain that is related to exercise, decreased stamina, palpitations or "skipping beats", and/or fainting. Undetected aortic stenosis can cause sudden death during vigorous physical exertion. Critical aortic stenosis in an infant can cause congestive heart failure with symptoms of poor feeding, rapid breathing, clammy sweating, lethargy, and/or irritability.

Physical findings: Aortic stenosis is often diagnosed due to the presence of a heart murmur. Infants may have symptoms of congestive heart failure as described above as well as weak pulses.

Medical tests: The gold standard for diagnosis is an echocardiogram. Cardiac catheterization is done if there are any questions not clearly answered by the echocardiogram and may also be done for therapeutic purposes, that is, to perform a balloon dilatation or angioplasty.

Aortic stenosis often progresses over time. Balloon angioplasty may be the only intervention required but is often used as a temporary means to delay open-heart surgery. This procedure is done in the heart catheterization laboratory. During the procedure, catheters (thin plastic tubes) are placed into the large blood vessels in the legs and gently guided to the heart. The catheter tip is placed across the aortic valve and the balloon tip is inflated. The balloon gently dilates the narrowed area. The incidence of complications is low and includes damage to the femoral artery, bleeding, perforation, and aortic valve leakage.

This procedure is a type of repair to the aortic valve in which the valve itself is stretched to allow better blood flow. During surgical valvotomy, an incision is made down the center of the breastbone. The heart is stopped for a brief period of time while the body is supported with a heart lung bypass machine (ECMO). The defect is then fixed by making an incision into the ascending aorta where it exits the left ventricle. An instrument called a dilator is then placed through the aorta and through the opening of the aortic valve stretching it. Progressively larger dilators are used until the valve is opened as much as possible without overstretching the valve which would allow it to leak blood backwards into the ventricle.

Sometimes the aortic valve is too narrow or too leaky to repair. When this happens the aortic valve will eventually need to be replaced. The goal is to identify when the valve function is poor enough to cause overwork for the heart, but before there is permanent damage. This is done through the history and physical examination as well as heart tests done during routine clinic visits. There are several types of valve replacement procedures and the choice of which operation is best for a child is decided through discussions with the parents, the pediatric cardiologist, and the pediatric cardiac surgeon. Valve replacements alone are not always enough to relieve the narrowing out the ventricle. 

Sometimes the whole area leading out of the ventricle to the aorta is too small. The supporting structure of the valve, called the valve annulus, may be too narrow even if the leaflets are opened up as far as possible. In these cases the valve replacement is performed with a procedure called a Konno procedure. This involves enlarging the left ventricular outflow tract and the valve ring. It is done through an incision into the outflow tract of the right ventricle and the septum or wall between the right and left ventricles. A patch is placed in this area that enlarges it. The Konno procedure can be done with any type of aortic valve replacement.

Subvalvar stenosis can be caused by a discrete membrane or by thickened muscle. Repair for discrete membranous stenosis is done to prevent damage to the aortic valve and to preserve left ventricular function. An incision is made down the center of the breastbone and the heart is stopped for a brief period of time while a heart-lung bypass machine supports the body. An incision is made in the aorta and the surgeon looks through the valve to visualize the membrane. The membrane is cut away along with a tiny pie shaped wedge of muscle. This is called membrane resection with myectomy and decreases the chances that the membrane will grow back. Muscular subaortic stenosis is a more diffuse narrowing that sometimes involves the mitral valve. 

The operation is performed in the same manner as discrete subaortic stenosis using the heart lung bypass machine. The surgeon incises the aorta and looks through the aortic valve to cut away the thickened muscle tissue. Care is taken to avoid the mitral valve structures. This type of narrowing is more difficult to treat and another operation to enlarge the entire left outflow tract may be required at a later time.

An incision is made down the center of the breastbone and the heart is stopped for a brief period of time while a heart lung bypass machine supports the body. The surgeon makes an incision along the length of the narrowing in the aortic wall. A patch is then placed into the area where the incision was made to open the area and relieve the narrowing. The size and length of the patch is determined by the degree of narrowing of the aorta.