Mitral valve prolapse - click-murmur syndrome
Another name for mitral valve prolapse is click-murmur syndrome. Mitral valve prolapse (MVP) is one of the most common conditions affecting the valves of the heart. It occurs when the twin flaps (leaflets) of tissue that make up your heart's mitral valve billow up and don't close correctly.
The mitral valve separates the two chambers on the left side of your heart: the left atrium and the left ventricle. When the mitral valve malfunctions and doesn't close properly, blood may leak from the ventricle back into the atrium.
When a doctor listens to your heart using a stethoscope, he may hear a clicking sound as the valve's leaflets billow out, as well as a murmur resulting from blood flowing back into the atrium. Doctors also use other names to describe MVP, such as:
Mitral valve prolapse affects about 2 percent of the adult population. In the past, doctors overdiagnosed MVP before they began using sophisticated tools to help in the diagnosis. Men and women appear to develop MVP in similar numbers.
In most people, MVP is harmless, and doesn't require any changes in lifestyle. It also doesn't shorten your life expectancy.
Signs and symptoms
Although MVP is a lifetime disorder, most people with this condition never have signs and symptoms. When diagnosed, most people are surprised to learn that they have a heart abnormality because of their absence of signs and symptoms.
When signs and symptoms do occur with MVP, they can vary widely from one person to another. They tend to be mild, develop gradually and may include:
When your heart is working properly, the mitral valve opens and closes to regulate the movement of blood between your heart's upper-left chamber (left atrium, or holding chamber) and the lower-left chamber (left ventricle, or pumping chamber). But in some people, their mitral valve malfunctions, bulging (prolapsing) like a parachute into their left atrium each time the heart pumps or contracts. The bulging may keep the valve from closing tightly. As a result, rather than all of the blood flowing normally in one direction, some blood may leak back into the atrium.
Doctors usually can't identify the cause of MVP. There may be a hereditary component to the disorder in some people, and the condition frequently runs in families. People with Marfan syndrome, in which the mitral valves are enlarged, tend to have an increased susceptibility to MVP.
If you have MVP, the flaps of your mitral valve may be misshapen or oversized. Women who develop MVP are often thin and have curvature of the spine (scoliosis) or minor skeletal abnormalities of the chest wall. Some also may have a hole in the walls separating the upper heart chambers, a condition called atrial septal defect.
The mitral valve separates the two chambers (atrium and ventricle) of the left side of the heart.
When to seek medical advice
If you develop what may appear to be the signs or symptoms of MVP, contact your doctor. If you've already been diagnosed with this disorder, see your doctor if your symptoms worsen.
Screening and diagnosis
Most frequently, doctors diagnose mitral valve prolapse during young adulthood. Your doctor is most likely to detect MVP during a routine examination of your heart using a stethoscope. If MVP is present, he or she may hear abnormal sounds, such as a characteristic clicking noise that suggests MVP. This clicking sound typically occurs midway through the beating portion of each heartbeat cycle, followed by a murmur or whooshing noise. The clicking sound is made by the flapping of the mitral valve's leaflets, and the murmur is associated with the backward flow of blood into the atrium.
To confirm the diagnosis, you may undergo an echocardiogram, which is a noninvasive, painless ultrasound (sonar) evaluation of your heart. This test uses high-frequency sound waves to create a picture of your heart and its structures, including the mitral valve itself and the flow of blood through it. Your doctor can view and analyze this image on a TV monitor.
In some cases, you may need to undergo additional tests to provide more details about your heart's valves and help in the diagnosis, including ruling out other conditions of the heart. These tests may include:
Once you've received a diagnosis of MVP, your doctor may suggest testing for your first-degree relatives — parents, siblings and children —to determine if they also have this condition.
Complications are rare in MVP. When they do develop, complications occur most often in middle-age or older adults. In people with a diagnosis of mitral valve regurgitation (mitral insufficiency) — a condition in which the valve is particularly leaky and allows excessive blood back into the left atrium — their doctor may sometimes recommend surgery to repair or even replace the valve in order to prevent the development of complications such as congestive heart failure. This regurgitation of blood also increases the likelihood of acquiring an infection called bacterial endocarditis, which can affect the mitral valve or the heart's lining. People with MVP who have had surgery or dental work are at a small but increased risk of this infection.
Although doctors have reported cases of sudden cardiac death associated with MVP, such fatalities are extremely rare. When fatalities do occur, these sudden deaths appear to result from an arrhythmia. People with severe mitral regurgitation, or severe deformity of their mitral valve, are most susceptible.
Most people with mitral valve prolapse, particularly people without any symptoms of MVP, don't require treatment.
If you develop symptoms, your doctor might prescribe certain medications to treat MVP-related chest pain or heart rhythm abnormalities. For example, doctors sometimes recommend drugs called beta blockers for irregular heartbeats or chest discomfort. Never stop taking these medications or change their dose without your doctor's approval.
Make sure your dentist or dental hygienist knows that you have mitral valve prolapse if you need to undergo dental work likely to cause gum bleeding, including routine cleaning. Also, tell your surgeon about your MVP before operations such as tonsillectomies, gallbladder surgery or prostate surgery. You may need to take a course or two of antibiotics before the treatment or surgery in order to reduce the risks of an infection. The prophylactic use of antibiotics destroys most of the bacteria that enter and travel through your bloodstream, thus preventing an infection of the heart valve. Your doctor may consider using antibiotics to be particularly important if you have mitral regurgitation, which carries a higher risk of infections. However, many doctors recommend prophylactic antibiotics for anyone with moderate to severe MVP. Amoxicillin is one of the most commonly prescribed medications for this use, but if you're allergic to the penicillin family of drugs, your doctor can choose other antibiotics instead, such as clindamycin, cephalexin or azithromycin.
If you're pregnant and have MVP, your chances of a successful, uncomplicated pregnancy are good. Even so, doctors sometimes recommend antibiotics during childbirth if there's a risk of an infection that could affect the mitral valve.
If you don't have MVP-associated signs or symptoms, and thus aren't receiving any treatment for this disorder, your doctor may still advise being rechecked every three to five years to monitor whether the condition has progressed.
You can't prevent mitral valve prolapse. However, you can lower your chances of developing the complications associated with it — particularly bacterial infections that may occur during surgery or dental treatments — by letting your doctor or dentist know that you have MVP. When appropriate, you'll receive prophylactic antibiotics prior to any procedures. If you develop any signs and symptoms of a bacterial infection — including fever, chills or headaches — contact your doctor.
Most people with MVP lead normal, productive and symptom-free lives. Doctors generally won't recommend any restrictions on your lifestyle, or any limitations on your personal exercise or dietary program.