In aortic valve stenosis, the valve between the lower left chamber of the heart (the left ventricle) and the main artery carrying blood from the heart to the body (the aorta) is narrowed. Aortic stenosis can be due to:
- Fusion of the valve leaflets, the door-like structures that open to allow blood to flow out of the heart and close to prevent it from leaking backward, or
- A “doorway” for blood flow that is too small.
Aortic stenosis is rare in infancy. Its incidence increases with age, and it becomes a common congenital heart disease in the third decade of life.
If aortic stenosis is mild or moderate, there may be no symptoms. If it is severe, symptoms may include:
- Shortness of breath
- Fainting (syncope)
- Abnormal heart rhythms
Progression and Possible Complications
Aortic stenosis may be mild, moderate, severe or critical.
Mild narrowing of the aortic valve opening usually causes no problems. However, with moderate or severe narrowing, the heart’s left ventricle must work harder to pump blood through a too-small opening. The extra work leads to thickening of the wall of the ventricle, a condition called left ventricular hypertrophy.
Eventually the overworked left ventricle can become tired, causing it to fail in its efforts to pump blood to the body, a condition called heart failure. Left ventricular heart failure leads to high blood pressure in the lungs. Shortness of breath and, eventually, right heart failure may occur. Left ventricular failure will also result in the heart being unable to provide the body with the amount of blood it needs. One result for the child is tiredness or fatigue.
Critical aortic stenosis is the extreme narrowing of the aortic valve in newborns. Before birth, a baby can survive well with only one well-functioning ventricle. That is not the case after birth. With critical aortic stenosis, the left ventricle is not able to pump blood adequately through the narrowed aortic valve and into the body. As a result, a child with this defect will become very ill soon after birth. Unless the condition is treated immediately, it could lead to death.
No treatment is generally recommended for mild aortic stenosis. However, ongoing monitoring of the condition is important to determine any change toward a moderate or severe level.
If aortic stenosis is moderate or severe, an interventional cardiologist may be able to use special tools to separate the fused valve leaflets – and thereby widen the opening for blood flow.
Balloon dilation (widening) of the aortic valve, using a thin, flexible tube (catheter) with an inflatable balloon at its tip, may be recommended in some cases to open the valve wider. This procedure is performed in the hospital's cardiac catheterization laboratory by specialized pediatric cardiologists.
Critical aortic stenosis requires immediate medical attention. This usually involves starting the infant on a medication to keep the blood vessel that normally closes soon after birth (patent ductus arteriosus) open until the aortic valve can be opened up in the catheterization lab.