What Is Mitral Valve Stenosis?
Your mitral valve is located on the left side of your heart, between two chambers, the atrium and the ventricle. Blood is pumped from the left atrium through the mitral valve and into the left ventricle on its way to the aorta. The mitral valve allows blood to pass through but prevents it from flowing back.
In mitral valve stenosis, also known as mitral stenosis, the mitral valve opening is narrowed. This means that not enough blood can flow through it, which can lead to a variety of issues, including fatigue, blood clots, and heart failure.
Scarring caused by rheumatic fever is the leading cause of mitral valve stenosis. Although rheumatic fever is common in some countries, it is becoming rare in the United States. Consequently, mitral valve stenosis is also uncommon in the United States, according to the National Institutes of Health (NIH).
What Causes Mitral Valve Stenosis?
- Mitral valve stenosis is typically caused by rheumatic fever. This is usually a childhood disease, and it results from the body’s immune response to an infection with the streptococcal bacteria. It is a serious complication of strep throat or scarlet fever.
- The body’s organs most affected by the acute rheumatic fever are the joints and the heart. The joints can become very inflamed and can lead to temporary and sometimes chronic disability. The lining of the heart (endocarditis), the heart muscle (myocarditis) and the membrane surrounding the heart (pericarditis) can become inflamed. When the mitral valve becomes involved, this leads to a chronic heart condition called rheumatic heart disease. The clinical signs and symptoms of this condition might not occur until five to ten years after the episode of rheumatic fever.
According to the Merck Manual Home Health Handbook, most U.S. cases of mitral stenosis are in older adults who had rheumatic fever before the widespread use of antibiotics or in people who have moved from countries where rheumatic fever is common (Merck).
A congenital heart defect may cause mitral valve stenosis in a baby. Babies born with this condition usually need surgery.
In rare cases, calcium may build up and cause narrowing of the mitral valve. Other rare causes for mitral valve stenosis include:
- blood clots
- radiation treatments
- calcium build up on vales
- congenital heart defects
What Are the Symptoms of Mitral Valve Stenosis?
Mitral valve stenosis commonly leads to shortness of breath, especially during exercise or when lying down. Other common symptoms include:
- cough, with or without blood
- swelling in ankles and/or feet
- respiratory infections
- plum-colored cheeks
If mitral valve stenosis is severe, you may feel your heart fluttering or beating rapidly.
Rarely, you may feel discomfort in your chest. Your chest might feel tight or constricted, or you may feel pain that radiates outward from your chest.
In some cases, mitral valve stenosis may not cause any symptoms, or the symptoms may appear only during exercise. You might develop symptoms when your body undergoes stress such as during an infection or pregnancy.
In addition to the common symptoms, children with this issue might experience slower growth.
How Is Mitral Valve Stenosis Diagnosed?
There are several tests that your doctor may use to diagnose mitral valve stenosis:
Your doctor will listen to your heart with a stethoscope. In people with this condition, the heart often makes unusual sounds such as rumbling and snapping.
Your doctor may use a variety of imaging tests to determine the cause of symptoms, including:
- echocardiogram: an image of the heart’s structure and function produced by ultrasound waves
- X-rays of heart and lungs (looking at size of left atrium and whether lungs are congested)
- transesophageal echocardiogram: an image of the heart produced when a device that emits ultrasound waves is threaded into your esophagus. This method creates a more detailed picture than a traditional echo because the esophagus is right behind the heart.
- cardiac catheterization: a long, thin tube is inserted into your arm, upper thigh, or neck and threaded up to your heart. This allows your doctor to do a variety of tests, including getting an image of the heart’s blood vessels.
Tests for Heart Rhythm Irregularities
Tests that can monitor your heart for rhythm abnormalities include:
- electrocardiogram: a recording of your heart’s electrical activity
- Holter monitoring: when your heart’s electrical activity is recorded using a portable monitoring device worn over a period of time (24-48 hours usually)
Your doctor may have you work out, and then monitor you while you exercise to determine how your heart responds to physical stress.
How is Mitral Valve Stenosis Treated?
Treatment for mitral valve stenosis can vary greatly depending on your symptoms and the severity of the condition. If you have no symptoms and only mild mitral valve stenosis, you might not need any treatment.
Drugs and Medication
If your mitral valve stenosis is causing symptoms, your doctor might prescribe medications. Although these do not actually fix the problem with your mitral valve, they can help treat your symptoms. Types of medications your doctor might prescribe include:
- anticoagulants (blood thinners)
- diuretics (to reduce fluid buildup through increased urine output)
- antiarrhythmics (medications to treat abnormal heart rhythms)
- beta-blockers (medications to slow your heart rate).
Your doctor may choose to perform a mitral balloon valvuloplasty if you need more treatment than just medications but your mitral valve is not damaged enough to require surgery. This involves threading a tube (catheter) with a balloon attached to it through a vein and into your heart. Once in the mitral valve, the doctor inflates the balloon to expand the valve. In some cases, you may need to undergo this procedure more than once.
Surgery may become necessary. Your doctor might be able to surgically repair your existing mitral valve to make it function properly. If that isn’t possible, you may need to have your mitral valve replaced with a new one. The replacement might be biological (from a cow, pig, or human cadaver, for example) or mechanical.
Making Lifestyle Changes to Improve Your Health
Although lifestyle changes cannot repair mitral valve stenosis, they may ease your symptoms or help keep the problem from worsening.
Your doctor might suggest that you make changes to your diet. These typically involve consuming less:
You should reach or maintain a weight that is healthy for you. Your doctor may instruct you to exercise to help you get or stay fit. However, your exercise regime must take your condition into account because exercising too vigorously might cause your symptoms to flare up.