The mitral valve is located on the left side of your heart, between two chambers: the atrium (upper) and the ventricle (lower). Blood is pumped from the left atrium, through the mitral valve, and into the left ventricle on its way to the aorta. The healthy mitral valve allows blood to pass through, but prevents it from flowing back.
Mitral valve stenosis, also known as mitral stenosis, is when the mitral valve opening is narrowed. This means that not enough blood can flow through it. This can lead to a variety of issues, including fatigue, difficulty breathing, 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 has become rare in the United States due to early recognition and treatment of streptococcal infections.
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 (or any of the heart valves) 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 5 to 10 years after the episode of rheumatic fever.
According to the American Heart Association (AHA), most U.S. cases of mitral stenosis are in older adults who had rheumatic fever before the widespread use of antibiotics. It is also more likely to occur in people who have moved from countries where rheumatic fever is common.
The factors that make some people more susceptible than others to mitral valve stenosis are unclear, but it is estimated that women are more at risk than men, according to the American Heart Association.
A congenital heart defect may cause mitral valve stenosis in a baby. Babies born with this condition usually need surgery, according to medical journal Research in Cardiovascular Medicine.
In rare cases, calcium may build up and lead to narrowing of the mitral valve. Other, more rare causes for mitral valve stenosis include:
- blood clots
- radiation treatments
- calcium buildup on valves
- congenital heart defects
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
- chest pain, or chest discomfort
- 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.
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. According to the Mayo Clinic, a heart “murmur,” arrhythmia, and fluid in the lungs are all indicators of mitral valve stenosis.
Your doctor may use a variety of imaging tests to confirm the diagnosis, as well as to deduce the original cause of the problem, including:
- Echocardiogram is an image of the heart’s structure and function produced by ultrasound waves. This is by far the most commonly used diagnostic test.
- Chest X-ray provides images of heart and lungs.
- Transesophageal echocardiogram (TEE) is 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 is 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. This is the most invasive and risky procedure, but also the most accurate.
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 to 48 hours usually)
Your doctor may have you perform moderate aerobic activity, and then monitor you while you exercise to determine how your heart responds to physical stress.
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 medication, but your mitral valve is not damaged enough to require heart surgery, this procedure is an option. 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.
If undetected or untreated, mitral valve stenosis can result in serious complications. Most commonly, these clients will develop arrhythmia (irregular heartbeat). Atrial fibrillation, in which the upper chambers of the heart tremble, will develop in many cases. If undetected or untreated, mitral valve stenosis can result in serious complications.
Endocarditis (an infection of the heart) and heart failure can occur.
Mitral valve stenosis also affects the lungs. Fluid buildup in the lungs (pulmonary edema) and pulmonary hypertension may develop as a result of mitral valve stenosis.
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:
- other stimulants (such as cough and cold medicines)
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.