|Anatomy and Physiology of the Heart :
The heart is a muscle that pumps oxygenated blood and nutrients to the body's cells.
There are four chambers in the heart: The top two chambers are called the right and left atria, and the bottom two chambers are the right and left ventricles.
There are four valves which maintain the free flow of blood in a forward direction through the heart chambers, then out through the arteries. The valves open to allow blood to move in a forward direction, then they close tightly to prevent a backwards flow of blood. The opening & closing of the valves creates the heart sounds heard by a stethoscope. (Illustration courtesy of the National Institute of Arthritis and Musculoskeletal and Skin Diseases)
The mitral valve is one of four heart valves which maintain the free flow of blood in a forward direction through the heart. Mitral valve stenosis is a heart condition in which the mitral valve is narrowed (stenotic) and fails to open as wide as it should. As a result, blood can't efficiently move from the left atrium to the left ventricle. Over time, the narrowed valve opening may make the heart work very hard to pump blood through it. This can lead to an enlarged left atrium.
The enlarged left atrium often beats rapidly in an irregular pattern (a disorder called atrial fibrillation). As a result, the heart's pumping efficiency is reduced.
Other potential complications include heart failure, stroke, heart infection, pulmonary edema, and blood clots.
|Causes of Mitral Valve Stenosis
| The most common cause of mitral valve stenosis is rheumatic fever, which can result from an untreated strep throat infection. Other less common causes of mitral valve stenosis include: A congenital heart defect , infection of the mitral valve or the adjacent heart muscle (infective endocarditis), metabolic disorders, such as Fabry's disease or Hurler-Scheie syndrome, hardening of the mitral valve components due to aging, and conditions that cause scarring of the mitral valve (lupus, rheumatoid arthritis, carcinoid syndrome). A noncancerous tumor in the left atrium (myxoma), can cause a blockage of the mitral valve.
|Symptoms of Mitral Valve Stenosis
| Significant symptoms of mitral valve stenosis usually take 10 to 20 years to develop, however the course is variable and somewhat unpredictable; some patients may not have symptoms for as long as 40 years.
- People with heart failure become easily fatigued and short of breath. Shortness of breath may occur only during physical activity at first, but later, it may occur even during rest. Some people cannot breathe comfortably when they are lying flat and need to sleep propped up with pillows or sitting upright.
- Weakness or dizziness can occur. You may feel too weak to carry out your normal daily activities. Dizziness can also occur, and in some cases, passing out may be a symptom.
- Chest discomfort, pain, or pressure, may occur with activity or when going out in cold air.
- Palpitations. This may feel like a rapid heart rhythm, irregular heartbeat, skipped beats or a flip-flop feeling in your chest.
- Swelling of your ankles, feet or abdomen. This is called edema. Swelling may occur in your belly, which may cause you to feel bloated.
- Rapid weight gain due to fluid retention can occur. A weight gain of two or three pounds in one day is possible.
- Coughing up blood can occur if the high pressure causes a vein or capillaries in the lungs to burst. Usually only a small amount of blood may be coughed up.
Note: Your doctor or health care provider should be consulted if any of the above symptoms develop or change in character.
| Diagnosis & Medical Treatment of Mitral Valve Stenosis
| Mitral stenosis produces a characteristic heart murmur as blood passes through the narrowed valve opening from the left atrium into the left ventricle. The doctor can often hear this murmur with a stethoscope. Unlike a normal valve, which opens silently, the abnormal valve often makes a snapping sound as it opens to allow blood into the left ventricle. The diagnosis is usually confirmed by echocardiography, which uses ultrasound waves to produce an image of blood passing through the narrowed valve opening.
Mitral stenosis in people of all ages is treatable. Treatment depends on the severity and progression of the condition and symptoms. Patients with mild, stable symptoms may only require periodic monitoring of their condition with an echocardiogram. Medications cannot correct a defect in the mitral valve. However, once symptoms become more significant, medications may be prescribed to relieve the symptoms and prevent complications:
- Diuretics may be prescribed to reduce fluid accumulation in the lungs or elsewhere.
- Drugs may be necessary to treat atrial fibrillation or other rhythm disturbances associated with mitral stenosis.
- Antibiotics may be prescribed before certain dental or medical procedures. These procedures may increase the likelihood of bacteria entering your bloodstream that can cause an infection in your heart (endocarditis).
- Anticoagulation (thinning of the blood with medication) can be an important method of preventing blood clots from forming in a heart with a damaged valve and causing a stroke, particularly in patients who have an irregular heart rhythm.
Surgery If the condition is severe enough, you may need heart surgery to repair or replace the valve. Left unchecked, mitral stenosis can lead to serious heart complications
| Educational Video Tutorials
| Mitral Valve Stenosis from Merck.com This page is a good handout but also has an animated multimedia illustration of the narrowed valve opening with resultant reduced blood flow from the left atria into the left ventricle|
Mitral Valve Stenosis from Merck Source Click on the above link, once on this page, click on "Interactive Human Atlas", then scroll down the list to find Mitral Valve Stenosis
Echocardiogram from Medline Plus. Scroll down to "Tests and Diagnostic Procedures" and select "echocardiogram" (Medline Plus is a service of the National Library of Medicine and the National Institute of Health)
Heart Valve Replacement from Medline Plus. Scroll down to "Surgery and Treatment Procedures" and select "Heart Valve Replacement" (Medline Plus is a service of the National Library of Medicine and the National Institute of Health)
| Internet References
| Mitral Valve Stenosis from Merck.com
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