Aortic stenosis (AS) is the narrowing or obstruction of the heart’s aortic valve; this prevents it from opening properly and blocks the flow of blood from the left ventricle to the aorta. As the aortic valve becomes more narrow, the pressure increases inside the left heart ventricle; in turn the left ventricle becomes thicker and decreases blood flow and can cause chest pain. As the pressure continues to increase, blood may back up into the lungs and cause shortness of breath. Severe forms may affect blood flow to the brain and lightheadedness and dizziness may result.
Aortic stenosis may be present from birth (congenital) or develop later in life (acquired). Causes of aortic stenosis include rheumatic fever or calcification of the valve. When it is due to calcification, it is usually not seen until a person reaches their 70’s. It is more common in men.
Normally the aortic valve has 3 parts, called “leaflets” that open and close. It functions as a one way valve.
5 of every 10,000 people in the US have AS. Approximately 1-2 % of the population have only 2 valve leaflets and are at increased risk of developing aortic stenosis (these patients often develop symptoms between the ages of 40 and 60).
Symptoms:
There may be no symptoms until late in the disease. Symptoms may include:
- Fainting, weakness or dizziness
- Shortness of breath with activity
- Palpitations
- Chest pain
The health care provider may be able to feel a vibration or movement when the hand is over the heart. A murmur, click, or abnormal sound is generally heard with a stethoscope. You may have low blood pressure.
Risk Factors:
As the aortic valve becomes more narrow, the pressure increases inside the left heart ventricle. This causes the left heart ventricle to become thicker, which decreases blood flow and can lead to chest pain. As the pressure continues to rise, blood may back up into the lungs, and you may feel short of breath. Severe forms of aortic stenosis prevent enough blood from reaching the brain and rest of the body. This can cause light-headedness and fainting.
Aortic stenosis may be present from birth (congenital), or it may develop later in life (acquired). Children with aortic stenosis may have other congenital conditions.
In adults, aortic stenosis occurs most commonly in those who've had rheumatic fever, a condition that may develop after strep throat or scarlet fever. Valve problems do not develop for 5 - 10 years or longer after rheumatic fever occurs. Rheumatic fever is increasingly rare in the United States.
Only rarely do other factors lead to aortic stenosis in adults. These include calcium deposits forming around the aortic valve, radiation treatment to the chest, and some medications.
How it is Diagnosed:
- Echocardiogram
- Electrocardiogram (EKG)
- Left heart catherization
- Chest X-ray
- Doppler ultrasound
- Transesophageal echocardiogram
Treatment Options:
If there are no symptoms or the symptoms are mild, you may only need to be monitored by your health care provider.
If there are symptoms (difficulty breathing, chest pain, fainting episodes), you need a physical exam every 6 to 12 months and an ECG every 1 to 3 years. Patients with severe aortic stenosis will need an echocardiogram at least annually. Symptomatic patients should avoid strenuous physical activity. Medications to treat heart failure may be used (diuretics, digoxin, etc). Surgery may be recommended to repair or replace the valve in patients who have symptoms. Because patients with aortic stenosis often also have blockages in the coronary arteries, most patients undergo cardiac catheterization before valve surgery to detect any blockages.
Valve replacement surgery is usually indicated in patients who have been diagnosed with severe AS, regardless of symptoms. Replacement of the valve requires open heart surgery.
There are 3 basic types of valves used to replace a diseased heart valve.
- A porcine valve is made of tissue from a pig. Patients with pig valves do not have significant risk for blood clots and do not require blood thinner medication. After approximately 10 years these valves may need to be replaced.
- A mechanical valve is made from metal and synthetic materials; these are more durable and often last more than 20 years, but with these there is a small risk for a blood clot to form on the valve. To prevent this complication, patients are treated with Coumadin to decrease the risk of clot formation.
- A homograft valve is an aortic valve taken from a human donor and does not require the use of a blood thinner.
After surgery, valves generally are monitored with echocardiograms every 6 to 12 months. Patients with valve replacements also require prophylactic antibiotics before and after undergoing any type of invasive procedure.
Some high risk patients may be better candidates for a less invasive procedure called balloon valvuloplasty. With balloon valvuloplasty, a balloon is placed in an artery in the groin and advanced into the heart where it is placed across the valve and inflated. This may relieve the obstruction.
Persons with aortic stenosis, particularly moderate and severe forms, should not participate in strenous activities.
Other Infomation:
What can I do to prevent complications associated with aortic stenosis?
- Treat strep infections promptly to prevent rheumatic fever.
- Notify your healthcare provider and dentist about any history of heart valve disease before treatment of any condition. There is potential that dental work (including cleaning) and/or invasive procedures can introduce bacteria into the blood. Bacteria can infect a weakened valve causing endocarditis.
When should I call my provider?
Call when you have worsening or new symptoms (fainting, chest pain, shortness of breath and/or palpitations).