Definition

Aortic stenosis (AS) is a narrowing of the aortic valve in the heart. This valve is located between the left ventricle (lower pumping chamber) and the aorta. The aorta is the largest artery in the body. It transports blood from the heart throughout the body. The aortic valve has three cusps, or flaps, that control the direction and flow of the blood. Aortic stenosis causes obstruction or blockage of blood flow through this valve.

Causes

The main causes of aortic stenosis include:

• A birth defect of the aortic valve, which normally has three cusps:
  • An aortic valve that has only one cusp or is otherwise stenotic from birth
  • A bicuspid (two-part) aortic valve with progressive wear and tear
• Progressive calcification of the aortic valve with age (most common in elderly)
• Rarely, scarring of the aortic valve caused by rheumatic fever]]>

Risk Factors

A risk factor is something that increases your chances of getting a disease or condition.

• Sex: male
• Family members with valvular heart disease
• History of rheumatic fever

Symptoms

Aortic stenosis does not always produce symptoms. However, if symptoms do occur, they may include the following:

• Extreme fatigue after exercise or exertion
• Fainting with exercise or exertion
• Chest pain, such as squeezing, pressure, or tightness
• Sensation of rapid or irregular heartbeat (palpitations)
• Shortness of breath
• Dizziness
• Neurological symptoms of a stroke or mini-stroke]]>

In rare cases, aortic stenosis can cause sudden death with no previous symptoms.

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam. The doctor may be alerted to aortic stenosis 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 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; it may show signs of heart strain or enlargement.
• ]]>Echocardiogram]]> —a test that uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart
• ]]>Cardiac Catheterization]]> —an x-ray of the heart's circulation that is done after injection of a contrast dye

Treatment

If you have mild AS, your condition will be monitored, but may not need immediate treatment. If you have more severe AS, your doctor may advise you to avoid strenuous physical activity. If necessary, you may be given medications to help prevent heart failure.

Severe AS may require surgery. Options include:

]]>Aortic Valve Replacement]]>

This is the surgical replacement of a defective heart valve. Currently, there are two types of replacement valves used:

• Bioprostheses—These valves are made from animals such as cows or pigs, and may last about 10-15 years. Blood-thinning medication is usually not needed with this type of valve.
• Mechanical prostheses—These synthetic valves are more durable, and may last for 20–40 years. However, you will be required to take blood-thinning medication for the rest of your life to prevent blood clots.

Aortic Valve Replacement—Mechanical (St. Jude) and Bioprostheses (Porcine) Valve Shown

© 2009 Nucleus Medical Art, Inc.

Prevention

Aortic stenosis cannot be prevented. However, if you have AS, there are several things you can do to try to avoid some of the complications:

• Get regular medical care, including checkups and periodic electrocardiograms.
• Take antibiotics before any dental cleaning, dental work, or other invasive procedures. This will help prevent infection of the heart valve.
• If your valve problem was caused by rheumatic fever, talk to your doctor about antibiotic treatment to prevent future episodes of rheumatic fever.