What Is Mitral Valve Disease?
Mitral valve disease refers to conditions of the mitral valve. Located between the left chambers of your heart, this valve works to keep blood flowing properly. It allows blood to pass from your left atrium to your left ventricle but prevents it from flowing backward.
When your mitral valve does not work properly, you can experience symptoms such as fatigue and shortness of breath because the defective valve is allowing blood to flow backwards into the left atrium. When this happens, your heart will not pump enough blood out of the left ventricular chamber to supply your body with oxygen-filled blood. Many people with mitral valve disease experience no symptoms, however.
Mitral valve disease can be serious. Left untreated, severe cases can lead to heart failure or irregular heartbeats (arrhythmias), which may be life threatening.
Types of Mitral Valve Disease
There are three types of mitral valve disease:
Mitral Valve Stenosis
The valve opening becomes narrow. This means that not enough blood can pass through into your left ventricle.
Mitral Valve Prolapse
The flaps on the valve bulge instead of closing tightly. This might prevent the valve from closing completely, and regurgitation (backward flow) may occur.
Mitral Valve Regurgitation
Blood leaks from the valve and flows backward into your left atrium.
What Causes Mitral Valve Disease?
Mitral Valve Stenosis
Mitral valve stenosis is typically caused by rheumatic fever. Usually a childhood disease, rheumatic fever results from the body’s immune response to a streptococcal bacterial infection. Rheumatic fever is a serious complication of strep throat or scarlet fever.
The organs most affected by 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, the heart muscle, and the membrane surrounding the heart can become inflamed. These conditions are called endocarditis, myocarditis, and pericarditis, respectively.
If the mitral valve becomes inflamed or otherwise injured by this condition, it leads to the 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.
In general, mitral stenosis is becoming uncommon in the United States and other developed countries. This is because rheumatic fever is rare in these countries, where patients have access to antibiotics that treat bacterial infections such as strep throat (Merck).
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)
There are other causes of the condition, but these are rare. They include:
- blood clots
- calcium buildup
- congenital heart defects
- radiation treatment
Mitral Valve Prolapse
Mitral valve prolapse often has no specific or known cause. It often runs in families, and other conditions, such as scoliosis and connective tissue problems, can contribute to mitral valve prolapse. According to the National Heart, Lung, and Blood Institute, only about three percent of the U.S. population has mitral valve prolapse, and fewer people actually experience serious problems associated with the condition (NHLBI).
Mitral Valve Regurgitation
A variety of heart problems can cause mitral valve regurgitation. You may develop mitral valve regurgitation if you have had:
- endocarditis (inflammation of the heart’s lining and valves)
- heart attack
- rheumatic fever
Damage to your heart’s tissue cords or wear and tear to your mitral valve can also lead to regurgitation. Mitral valve prolapse can sometimes cause regurgitation.
What Are the Symptoms of Mitral Valve Disease?
Mitral valve disease symptoms vary depending on the exact problem with your valve. A problem with your mitral valve may cause no symptoms at all. When symptoms do occur, the can include:
- shortness of breath (especially when you are lying down on your back or exercising)
- fatigue and tiredness
You may also feel pain or tightness in your chest. In some cases, you might feel your heart beating irregularly or quickly.
In general, symptoms of any type of mitral valve disease develop gradually. Symptoms might appear or get worse when your body is dealing with some sort of extra stress, such as infection or pregnancy.
How Is Mitral Valve Disease Diagnosed?
If your doctor suspects that you may have a mitral valve disease, he or she will listen to your heart with a stethoscope. Unusual sounds or rhythm patterns can help him or her get a sense of what’s going on.
Other tests that may be performed to confirm a mitral valve disease diagnosis include:
- echocardiogram: an image of the heart’s structure and function produced by ultrasound waves
- 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 to Monitor Heart Activity
- 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 want to monitor you while you exercise to determine how your heart responds to physical stress.
How Is Mitral Valve Disease Treated?
Treatment for mitral valve disease may not be necessary, depending on the severity of your condition and symptoms.
Drugs & Medication
If treatment is necessary, your doctor may begin by treating you with medications. There are no medications that can actually fix the structural issues with your mitral valve. However, some medications can ease your symptoms or prevent them from getting worse. These medications may treat abnormal heart rhythms (antiarrhythmics), thin your blood (anticoagulants), slow your heart rate (beta blockers), or reduce accumulation of fluid in your lungs (diuretics).
In some cases, your doctor may need to perform more invasive procedures. For example, in cases of mitral valve stenosis, your doctor may be able to use a balloon to open up the valve in a procedure called balloon valvuloplasty.
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.