Aortic Stenosis
Pronounced: ay-ORE-tick sten-OH-sis
Definition |
Causes |
Risk Factors |
Symptoms |
Diagnosis |
Treatment |
Prevention |
Organizations
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 (this valve normally has three cusps):
- An aortic valve that has only one cusp or is otherwise stenotic from birth
- A bicuspid (2-part) aortic valve with progressive wear and tear
- Progressive calcification of the aortic valve with age (most common in elderly)
- 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:
Balloon Valvuloplasty
A balloon device is passed through the arteries to open or enlarge the stenotic aortic valve. This may provide temporary relief of symptoms. However, the valve can become blocked again.
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 not taken after this type of surgery.
- 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.
Prevention
Aortic stenosis cannot be prevented. But, 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.
- Treat strep throat infections promptly to avoid rheumatic fever, which can cause scarring 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.
Organizations
American Heart Association
http://www.americanheart.org/
National Heart, Lung, and Blood Institute (NHLBI)
http://www.nhlbi.nih.gov/index.htm
SOURCES:
Harrison's Principles of Internal Medicine, 14th ed. McGraw-Hill, 1998.
Last reviewed October 2001 by Medical Review Board
