Aortic valve stenosis
Aortic valve stenosis
Description, Causes and Risk Factors:
AVS is a narrowing of the aortic valve. The aortic valve allows blood to flow from the heart's lower left chamber (ventricle) into the aorta and to the body. AVS affects 3 percent of persons older than 65 years and leads to greater morbidity and mortality than other cardiac valve diseases.
The natural history of AVS involves a prolonged latent period, during which progressive worsening of left ventricular outflow (LVO) obstruction leads to hypertrophic changes in the left ventricle. As the aortic valve area becomes less than one half its normal size of 3 to 4 cm2, a measurable pressure gradient between the left ventricle and ascending aorta may be detected on echocardiography or by direct measurement at cardiac catheterization. This change reflects compensatory increases in LV pressures that contribute to the maintenance of adequate systemic pressures. One consequence is LV hypertrophy with subsequent diastolic dysfunction and increased resistance to LV filling. Thus, a strong left atrial contraction is needed to provide sufficient LV diastolic filling and support adequate stroke volume. Increasing overall myocardial contractility and augmenting preload with an increased atrial kick preserve LV systolic function, typically while the patient remains asymptomatic.
As aortic stenosis worsens with the aortic valve area decreasing to 1 cm2 or less, changes in LV function may no longer be adequate to overcome the outflow obstruction and maintain systolic function, even when complemented by an increase in preload. The resulting impairment in systolic function, alone or combined with diastolic dysfunction, may lead to clinical heart failure.
Problems that can lead to AVS include:
A heart defect you were born with (congenital).
Rheumatic fever or endocarditis. These infections can damage the valve.
Calcium buildup on the aortic valve. As you age, calcium can build up on the valve, making it hard and thick. This buildup happens over time, so symptoms usually do not appear until after age 65.
Symptoms may include:
Feeling faint or fainting with exertion.
Shortness of breath, especially with exertion.
Fatigue, especially during times of increased activity.
Heart palpitations — sensations of a rapid, fluttering heartbeat.
Chest pain (angina) or tightness.
Diagnostic tests may include:
If your doctor suspects that you or your child may have a deformed or narrowed aortic valve, you may need to undergo several tests to confirm the diagnosis and gauge the severity of the problem. You may be referred to a cardiologist — a doctor who specializes in the study of the heart and its function — for tests such as:
Chest X-ray. An X-ray image of your chest allows your doctor to check the size and shape of your heart, to determine whether the left ventricle is enlarged — a possible indicator of aortic valve stenosis. A chest X-ray can also reveal calcium deposits on the aortic valve. In addition, a chest X-ray helps your doctor check the condition of your lungs. Aortic valve stenosis may lead to blood and fluid backing up in your lungs, which causes congestion that may be visible on an X-ray.
Echocardiogram. This test uses sound waves to produce an image of your heart. In an echocardiogram, sound waves are directed at your heart from a wand-like device (transducer) held on your chest. The sound waves bounce off your heart and are reflected back through your chest wall and processed electronically to provide video images of your heart. An echocardiogram helps your doctor closely examine the aortic valve to check for problems. A specific type of echocardiogram, a Doppler echocardiogram, may be used to help your doctor determine the severity of your aortic valve stenosis and to check for any leakage (regurgitation).
Cardiac catheterization. Your doctor may order this procedure if noninvasive tests have not provided enough information to firmly diagnose the type or severity of your heart condition. Your doctor threads a thin tube (catheter) through an artery in your arm or groin to an artery in your heart. A dye injected through the catheter fills your heart's arteries, and the arteries become visible on an X-ray. This test helps show blockages in arteries to your heart that can coexist with aortic valve stenosis and may need surgical treatment along with aortic valve stenosis.
Electrocardiogram (ECG). In this test, patches with wires (electrodes) are attached to your skin to measure the electrical impulses given off by your heart. Impulses are recorded as waves displayed on a monitor or printed on paper. An ECG can provide clues about whether the left ventricle is thickened or enlarged, a problem which can occur with aortic valve stenosis.
If you do not have symptoms, your doctor will see you regularly to check your heart. You probably will not have surgery. Unless you have symptoms, or tests show that the heart's pumping action is getting weak, surgery is likely to be more risky than the disease.
If you have symptoms, you probably need surgery right away. Surgery to replace the aortic valve is the best treatment for most people. Some young people or people who cannot have open-heart surgery may have another procedure called balloon valvuloplasty to enlarge the valve opening.
If you do not have surgery after you start having symptoms, you may develop myocardial infarction or sudden death. Surgery can help you to have a more normal Lifespan.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.
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