Causes

In babies, AS is caused by a birth defect of the aortic valve that may result in:

• One cusp instead of three—When the heart valve is closed, the cusp seals the area.
• Two cusps that are damaged
• Cusps that are partly closed or do not open correctly due to thickness

Damage to the aortic valve can also be caused by certain conditions, like these infections:

• Rheumatic fever (usually occurring after a Streptococcus infection)
• Bacterial endocarditis

Risk Factors

These factors increase your child's chance of developing AS:

• Family members with congenital heart disease that affects valves
• History of rheumatic fever or bacterial endocarditis

Tell the doctor if your child has any of these risk factors.

Symptoms

If your child has AS, he may not have any symptoms. As your child ages, he may develop symptoms, such as:

• Extreme fatigue after exercise or exertion
• Fainting with exercise or exertion
• Pain, squeezing, pressure, or tightness of the chest, usually occurring with exertion
• Sensation of rapid or irregular heartbeat (palpitations)
• Shortness of breath
• Dizziness with exertion

In rare cases, AS can cause:

• Abnormal heart rhythms ( arrhythmia )
• Sudden death with no previous symptoms

Diagnosis

The doctor will ask about your child’s symptoms and medical history. A physical exam will be done. The doctor may be alerted of AS by the following:

• Abnormal chest sounds, such as a heart murmur or click
• Noticeable chest heave or vibration when the doctor's hand is held over your child’s heart

To confirm the diagnosis, tests may include:

• Chest x-ray —a test that uses radiation to take pictures of structures inside the chest
• Electrocardiogram (ECG, EKG)—a test that records the heart's activity by measuring electrical currents through the heart muscle; may show signs of heart strain or enlargement
• Echocardiogram —a test that uses sound waves (ultrasound) to examine the size, shape, and motion of the heart
• Exercise stress test —the recording of the heart during exercise
• Cardiac catheterization (rarely done)—an x-ray of the heart's circulation that is done after injection of contrast dye

Treatment

If your child has mild AS, his condition will be monitored. He may not need treatment right away.

Prevention

Congenital AS cannot be prevented.