Aortic Stenosis: Causes, Symptoms, Diagnosis, Treatment, and Prevention
Aortic stenosis is a condition where the aortic valve becomes narrowed and does not open fully, which separates the left ventricle (the main pumping chamber of the heart) from the aorta (the largest artery that carries blood to the rest of the body). As a result, the blood flow from the heart to the aorta and the rest of the body is reduced or blocked, which results in the heart working harder and potentially damaging itself. Untreated aortic stenosis can cause serious health problems and even death.
Causes of Aortic Stenosis
Aortic stenosis can have different causes depending on the age and health of the person. Some of the common causes are:
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This type of stenosis most commonly occurs after age 65, as calcium builds up on the valve, similar to what cholesterol does to blood vessels.
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As bacteria accumulate in the bloodstream from untreated infections, they can damage the valve, causing the immune system to attack. As a consequence of rheumatic fever, which is a complication of strep throat, or endocarditis, which is an infection of the heart tissue, this can happen.
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It is possible for some people to be born with a congenital heart defect that has only two leaflets instead of three, or that is abnormally shaped or fused.
Symptoms of Aortic Stenosis
Aortic stenosis may not cause any symptoms for many years, especially if it is mild or moderate. However, when the narrowing of the valve becomes severe, it can cause symptoms such as:
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Heart murmur: This is an abnormal sound that can be heard through a stethoscope when the heart beats. It is caused by the turbulent blood flow through the narrowed valve.
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Chest pain or tightness: This can occur with activity or stress, as the heart struggles to pump enough blood to the body. The pain may radiate to the neck, jaw, or arms.
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Shortness of breath or difficulty breathing: This can happen with exertion or when lying down, as the blood backs up in the lungs due to the reduced blood flow from the heart.
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Fatigue or weakness: This can result from the lack of oxygen and nutrients that the body receives due to the impaired blood flow from the heart.
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Dizziness or fainting: This can occur when the blood pressure drops due to the insufficient blood flow from the heart, especially when changing positions or standing up quickly.
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Palpitations or irregular heartbeat: This can happen when the heart tries to compensate for the reduced blood flow by beating faster or irregularly.
Diagnosis of Aortic Stenosis
Aortic stenosis can be diagnosed by a physical examination and various tests that can assess the condition and severity of the valve and the heart. Some of the tests that may be used are:
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An echocardiogram uses sound waves to produce images of the heart and its valves. It can measure the size, shape, and function of the heart and the flow of blood through it.
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An electrocardiogram (ECG or EKG) measures the electrical activity of the heart and can detect abnormal heart rhythms.
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An X-ray of the chest uses radiation to produce images of the heart and aorta, as well as other conditions that may be causing the symptoms.
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These tests use advanced imaging techniques to produce detailed images of the heart and aorta, as well as showing the structure and function of the valves.
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An invasive test, cardiac catheterization involves inserting a thin tube (catheter) into a blood vessel and guiding it to the heart through a blood vessel in the groin or arm. A dye is injected through the catheter to highlight the blood flow and the pressure in the heart and aorta. It is then possible to determine the degree of stenosis and whether treatment is required.
Treatment of Aortic Stenosis
It depends on the severity of aortic stenosis as well as the symptoms and risk factors of the patient to decide how to treat it. Treatment goals include relieving symptoms, preventing complications, and improving quality and length of life. Treatment options include:
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Medications help manage symptoms and underlying conditions that may worsen the stenosis, such as high blood pressure, high cholesterol, diabetes, or heart failure, but they cannot reverse or stop the stenosis' progression.
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As part of surgery, a damaged valve is replaced with an artificial one or a valve from a donor animal or human, which can restore normal blood flow and improve survival rates. Surgery is, however, not without risks and complications, including bleeding, infection, stroke, or valve failure. Because of this, surgery is usually reserved for individuals with severe stenosis and symptoms or a high risk of sudden death.
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Transcatheter aortic valve replacement (TAVR): This is a less invasive procedure that involves inserting a new valve through a catheter and placing it inside the old valve. The procedure can improve blood flow and symptoms without the need for open-heart surgery, though it also comes with risks and complications, such as bleeding, infection, stroke, or leakage of the valve. It is usually recommended for patients who are not suitable candidates for surgery or who have a high surgical risk to undergo TAVR.
Prevention of Aortic Stenosis
Aortic stenosis may not be preventable in some cases, such as those caused by congenital defects or aging. However, some steps can be taken to reduce the risk or delay the onset of the stenosis, such as:
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Eating a healthy diet: This can help lower the cholesterol and blood pressure levels and prevent the buildup of plaque and calcium on the valve and the blood vessels.
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Exercising regularly: This can help maintain a healthy weight and improve the heart function and the blood circulation.
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Quitting smoking: This can help reduce the damage to the heart and the blood vessels and lower the risk of infections and inflammation.
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Treating infections: This can help prevent the spread of bacteria to the heart and the valve and avoid the complications of rheumatic fever or endocarditis.
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Following up with the doctor: This can help monitor the condition of the valve and the heart and receive the appropriate treatment and advice.
