What Is Mitral Valve Prolapse?
Mitral (MI-tral) valve prolapse (MVP) is a condition
in which one of the valves of the heart, the mitral valve, doesnt work
properly. The flaps of the valve are floppy and dont close
tightly. Much of the time, MVP doesnt cause any problems. Rarely, blood
can leak the wrong way through the floppy valve, which may cause shortness of
breath,
palpitations,
chest pain, and other symptoms.
Normal Mitral Valve
The mitral valve controls the flow of blood between
the two chambers on the left side of the heart. The two chambers are the left
atrium (AY-tree-um) and the left ventricle (VEN-trih-kul). The mitral valve
allows blood to flow from the left atrium to the left ventricle, but not back
the other way. (The heart also has a right atrium and ventricle, separated by
the tricuspid (tri-CUSS-pid) valve.)
At the beginning of a heartbeat, the atria contract
and push blood through to the ventricles. The flaps of the mitral and tricuspid
valves swing open to let the blood through. Then, the ventricles contract to
pump the blood out of the heart. When the ventricles contract, the flaps of the
mitral and tricuspid valves swing shut and form a tight seal that prevents
blood from flowing back into the atria.
For more information, see the
How the Heart Works section.
Mitral Valve Prolapse
In MVP, when the left ventricle contracts, one or
both flaps of the mitral valve flop or bulge back (prolapse) into the left
atrium. This can prevent the valve from forming a tight seal, which allows
blood to flow backward from the ventricle into the atrium. The backward flow of
blood is called regurgitation (re-GUR-ji-TA-shun), and it can lead to symptoms
and complications.
Regurgitation doesnt occur in all cases of
MVP. In fact, the majority of people with MVP dont have regurgitation and
never have any symptoms or complications. In these people, even though the
valve flaps prolapse, the valve is still able to form a tight seal.
When regurgitation does occur, it can cause
complications and troublesome symptoms such as shortness of breath,
arrhythmias
(ah-RITH-me-ahs), or chest pain. Arrhythmias are problems with the rate or
rhythm of the heartbeat.
Regurgitation can get worse over time and lead to
changes in the hearts size and higher pressures in the left atrium and
lungs. Regurgitation increases the risk for heart valve infections.
Medicines can treat MVP symptoms that cause people
to worry or have discomfort. Medicines are also used to prevent complications.
Sometimes a person will need surgery to repair or replace the mitral valve.
Figure A shows the normal mitral
valve separating the left atrium from the left ventricle. Figure B shows the
heart with mitral valve prolapse. Figure C shows the detail of mitral valve
prolapse. Figure D shows a mitral valve that allows blood to flow backward into
the left atrium.
MVP was once thought to affect as much as 5 to 15
percent of the population. Its now believed that many people who were
diagnosed with MVP in the past didnt actually have an abnormal mitral
valve. They may have had a slight bulging of the valve flaps due to other
conditions such as dehydration or a small heart. However, their valve was
normal and there was little or no regurgitation through the valve.
Now, more precise rules for diagnosing MVP with a
test called an
echocardiogram make it easier to identify true MVP and to
detect troublesome regurgitation. Based on these new rules, its now
believed that less than 3 percent of the population actually have true MVP, and
an even smaller percentage has serious complications from it.
Outlook
Most people who have MVP have no symptoms or medical
problems and dont need treatment. These people are able to lead normal,
active lives; they may not even know they have the condition. A small number of
people who have MVP may need medicines to relieve their symptoms. Very few
people who have MVP need heart valve surgery to repair their mitral valve.
Rarely, MVP can cause complications, such as
arrhythmias (irregular heartbeats) or
infective endocarditis (EN-do-kar-DI-tis). Infective
endocarditis is a heart valve infection caused by bacteria that enter the
bloodstream and attach to the heart valves.
How the Heart Works
The heart is a muscle about the size of your fist.
It works like a pump and beats 100,000 times a day.
The heart has two sides, separated by an inner wall
called the septum. The right side of the heart pumps blood to the lungs to pick
up oxygen. Then, oxygen-rich blood returns from the lungs to the left side of
the heart, and the left side pumps it to the body.
The heart has four chambers and four valves and is
connected to various blood vessels. Veins are the blood vessels that carry
blood from the body to the heart. Arteries are the blood vessels that carry
blood away from the heart to the body.
A Healthy Heart Cross-Section
The illustration shows a
cross-section of a healthy heart and its inside structures. The blue arrow
shows the direction in which oxygen-poor blood flows from the body to the
lungs. The red arrow shows the direction in which oxygen-rich blood flows from
the lungs to the rest of the body.
Heart Chambers
The heart has four chambers or "rooms."
- The atria are the two upper chambers that collect
blood as it comes into the heart.
- The ventricles are the two lower chambers that
pump blood out of the heart to the lungs or other parts of the body.
Heart Valves
Four valves control the flow of blood from the atria
to the ventricles and from the ventricles into the two large arteries connected
to the heart.
- The tricuspid valve is in the right side of the
heart, between the right atrium and the right ventricle.
- The pulmonary (PULL-mun-ary) valve is in the
right side of the heart, between the right ventricle and the entrance to the
pulmonary artery, which carries blood to the lungs.
- The mitral valve is in the left side of the
heart, between the left atrium and the left ventricle.
- The aortic valve is in the left side of the
heart, between the left ventricle and the entrance to the aorta, the artery
that carries blood to the body.
Valves are like doors that open and close. They open
to allow blood to flow through to the next chamber or to one of the arteries,
and then they shut to keep blood from flowing backward.
When the heart's valves open and close, they make a
"lub-DUB" sound that a doctor can hear using a stethoscope.
- The first soundthe lubis
made by the mitral and tricuspid valves closing at the beginning of systole
(SIS-toe-lee). Systole is when the ventricles contract, or squeeze, and pump
blood out of the heart.
- The second soundthe DUBis
made by the aortic and pulmonary valves closing at beginning of diastole
(di-AS-toe-lee). Diastole is when the ventricles relax and fill with blood
pumped into them by the atria.
Arteries
The arteries are major blood vessels connected to
your heart.
- The pulmonary artery carries blood pumped from
the right side of the heart to the lungs to pick up a fresh supply of
oxygen.
- The aorta is the main artery that carries
oxygen-rich blood pumped from the left side of the heart out to the body.
- The coronary arteries are the other important
arteries attached to the heart. They carry oxygen-rich blood from the aorta to
the heart muscle, which must have its own blood supply to function.
Veins
The veins are also major blood vessels connected to
your heart.
- The pulmonary veins carry oxygen-rich blood from
the lungs to the left side of the heart so it can be pumped out to the
body.
- The vena cava is a large vein that carries
oxygen-poor blood from the body back to the heart.
For more information on how a healthy heart works,
see the Diseases and Conditions Index article on
How
the Heart Works. This article contains animations that show how your heart
pumps blood and how your hearts electrical system works.
Other Names for Mitral Valve Prolapse
- Balloon mitral valve
- Barlows syndrome
- Billowing mitral valve
- Click-murmur syndrome
- Floppy valve syndrome
- Myxomatous mitral valve
- Prolapsing mitral valve syndrome
What Causes Mitral Valve Prolapse?
The exact cause of mitral valve prolapse (MVP)
isnt known. Most people with the condition are born with it. It tends to
run in families and is more common in people who were born with connective
tissue disorders, such as
Marfan
syndrome.
The mitral valve can be abnormal in two ways. First,
the valve flaps may be oversized and thickened. Second, the valve flaps may be
floppy. The tissue of the flaps and their supporting
strings are too stretchy, and parts of the valve flop or bulge back
into the atrium. Some peoples valves are abnormal in both ways. Either
way can keep the valve from making a tight seal.
Who Is At Risk for Mitral Valve Prolapse?
Mitral valve prolapse (MVP) occurs in all age groups
and in men and women. MVP with complications or severe symptoms is seen most
often in men older than 50.
Certain conditions increase the risk for MVP,
including:
- Connective tissue disorders, such as
Marfan
syndrome
- Scoliosis and other skeletal abnormalities
- Some types of muscular dystrophy
- Graves disease
What Are the Signs and Symptoms of Mitral Valve
Prolapse?
The majority of people with mitral valve prolapse
(MVP) arent affected by the condition because they dont have any
symptoms or significant mitral valve regurgitation. Among those who do have
symptoms,
heart
palpitations (strong or rapid heartbeats) are reported most often.
Other symptoms include shortness of breath, cough,
dizziness, fatigue (tiredness), anxiety, migraine headaches, and chest
discomfort.
Symptoms can vary widely from one person to another.
They tend to be mild but can worsen over time, mainly when there are
complications of MVP.
Complications of Mitral Valve Prolapse
Complications of MVP are rare, but when present,
theyre most often due to regurgitation of blood through the valve. Mitral
valve regurgitation is most common among men and people with
high
blood pressure. People with severe cases of mitral valve regurgitation may
need valve surgery to prevent complications.
In mitral valve regurgitation, blood flows backward
from the left ventricle into the left atrium. It can even back up from the
atrium into the lungs, causing shortness of breath. The backward flow of blood
puts a strain on the muscles of both the atrium and the ventricle. Over time,
the strain can lead to
arrhythmias
(irregular heartbeats). Regurgitation also increases the risk of
infective endocarditis, an infection of the lining of the
valves.
Arrhythmias
Mitral valve regurgitation can cause arrhythmia, an
abnormal rate or rhythm of the heartbeat.
There are many different types of arrhythmia. The
most common arrhythmias are harmless. Others can be serious or even life
threatening. When the heart rate is too slow, too fast, or irregular, the heart
may not be able to pump enough blood to the body. Lack of blood flow can damage
the brain, heart, and other organs.
One troublesome arrhythmia that may be seen with MVP
and regurgitation is atrial fibrillation. In atrial fibrillation, the walls of
the atria quiver instead of beating normally. As a result, the atria
arent able to pump blood into the ventricles the way they should.
Atrial fibrillation is bothersome but rarely life
threatening unless its very fast or unless it causes blood clots to form
in the atria. Blood clots can form in the atria because some of the blood
pools there instead of flowing into the ventricles. If a blood clot
breaks off and goes into the bloodstream, it can reach the brain and cause a
stroke.
Infection of the Mitral Valve
A deformed mitral valve flap attracts bacteria that
may be found in the bloodstream. The bacteria attach to the valve and can cause
a serious infection called infective endocarditis. Signs and symptoms of a
bacterial infection include fever, chills, body aches, or headaches.
Infective endocarditis doesnt happen often,
but when it does, its serious. MVP is the most common heart condition
that puts people at risk for this infection.
Floss and brush your teeth regularly. Gum infections
and tooth decay can cause endocarditis.
How Is Mitral Valve Prolapse Diagnosed?
Mitral valve prolapse (MVP) is most often found
during a routine physical exam when your doctor uses a stethoscope to listen to
your heart. Your doctor listens for a certain click and/or
murmur.
Stretched valve flaps, as seen in MVP, can make a clicking sound as they shut.
If the valve is leaking blood back into the atrium, a murmur or whooshing sound
can often be heard. However, these abnormal heart sounds may come and go, so
they may not be heard at the time of an exam, even if you have MVP. As a
result, diagnostic tests and procedures may also be needed to diagnose MVP.
Diagnostic Tests and Procedures
Echocardiogram
An
echocardiogram is the most useful test for diagnosing MVP.
This test uses sound waves to create a moving picture of your heart. An
echocardiogram provides information about the size and shape of your heart and
how well your heart chambers and valves are functioning. The test also can
identify areas of poor blood flow to the heart, areas of heart muscle that are
not contracting normally, and previous injury to the heart muscle caused by
poor blood flow. The echocardiogram is a painless test thats used to look
for prolapse of the mitral valve flaps and for backflow (regurgitation) of
blood through the leaky valve.
There are several different types of
echocardiograms, including a stress echocardiogram. During this test, an
echocardiogram is done both before and after your heart is stressed either by
having you exercise or by injecting a medicine into your bloodstream that makes
your heart beat faster and work harder. A stress echocardiogram is usually done
to find out if you have decreased blood flow to your heart (coronary
artery disease).
Echocardiography also can be performed through your
esophagus (the tube leading from your mouth to your stomach) to get a closer
look at the mitral valve. A tiny probe in your esophagus takes sound wave
pictures of your heart. This form of echocardiogram is called a transesophageal
echocardiogram, or TEE.
Doppler Ultrasound
A Doppler
ultrasound is part of the echocardiogram test. The Doppler
ultrasound is used to show the speed and direction of blood flow through the
mitral valve.
Other Tests
Other tests that can help diagnose MVP are:
- A
chest
x ray, which is used to look for fluid in your lungs or to see if your
heart is enlarged.
- An
EKG
(electrocardiogram), which charts the electrical activity of your heart. The
EKG can show abnormal heartbeats, damage to the heart muscle, and enlargement
of the heart.
How Is Mitral Valve Prolapse Treated?
Goals of Treatment
The goals of treating mitral valve prolapse (MVP)
are to:
- Prevent
infective endocarditis, arrhythmias, and other
complications
- Relieve symptoms
- Correct the underlying mitral valve problem when
necessary
Who Needs Treatment
Most people with MVP don't need treatment because
they don't have significant regurgitation of blood through the valve, and they
have few or no symptoms. Even people who do have symptoms may not require
treatment. The presence of symptoms doesn't necessarily mean that there is
significant regurgitation through the valve. People with MVP and troublesome
mitral valve regurgitation usually need treatment.
Specific Types of Treatment
MVP can be treated with medicine, surgery, or
both.
Medicine
For people with MVP who have little or no
regurgitation, medicines called beta blockers have been used to treat symptoms
such as
palpitations
(strong or rapid heartbeats) and chest discomfort.
For people with MVP who have significant
regurgitation and symptoms, the following medicines may be used to prevent
complications:
- Vasodilators to widen the blood vessels and
reduce the workload of the heart. Examples of vasodilators are isosorbide
dinitrate and hydralazine.
- Digoxin to strengthen the heartbeat.
- Diuretics (water pills) to remove excess fluid in
the lungs.
- Drugs such as flecainide and procainamide to
regulate heart rhythms.
- Anticoagulants (blood thinners) to reduce the
risk of blood clots forming in people with atrial fibrillation. Examples
include aspirin or warfarin.
Surgery
Surgery on the mitral valve is done only when the
valve is very abnormal and blood is regurgitating into the atrium. The main
goal of surgery is to improve symptoms and reduce the risk for
heart
failure.
The timing of the surgery is very important. If it's
done too early and your leaking valve is working fairly well, you may be put at
needless risk from surgery. If it's done too late, irreversible heart damage
may have already occurred.
Surgical approaches. The
traditional surgical approach for mitral valve repair and replacement is
through an incision in the breastbone to expose the heart. A small but growing
number of heart surgeons are using another approach that uses one or more
smaller incisions through the side of the chest wall. This approach can result
in less cutting, reduced blood loss, and a shorter hospital stay, but it isn't
available yet in all hospitals.
Valve repair versus valve
replacement. In mitral valve surgery, the valve may either be repaired
or replaced completely. Valve repair is preferred when possible. It's less
likely to weaken the heart, lowers the risk of infection, and decreases the
need for lifelong use of blood-thinning medicines.
If repair isn't an option, then the valve can be
replaced. Two types of substitute valves are available: a mechanical valve or a
biological valve.
Mechanical valves are made of man-made materials and
can last a lifetime. Patients with mechanical valves must take blood-thinning
medicines for life. Biological valves are valves taken from cows or pigs or
made from human tissue. Many patients with biological valves don't need to take
blood-thinning medicines for life. The major drawback of biological valves is
that they weaken and often only last about 10 years.
After surgery, a patient usually stays in the
intensive care unit in the hospital for 2 to 3 days. Most people spend about 1
to 2 weeks in the hospital. Complete recovery takes a few weeks to several
months, depending on the person's health before surgery.
If you've had valve repair or replacement, you may
need antibiotics before dental work and surgery that can allow bacteria into
the bloodstream. These medicines can help prevent infective endocarditis, a
serious heart valve infection. Talk to your doctor about whether you need to
take antibiotics before such procedures.
Experimental approaches. Some
researchers are testing the repair of leaky valves using a catheter inserted
through a large blood vessel. While this approach is less invasive and can save
the patient from having open heart surgery, it's only being done in a few
medical centers. In addition, because it's a new procedure, it hasn't yet been
shown in large studies to be better than traditional approaches.
How Can Mitral Valve Prolapse Be Prevented?
You can't prevent mitral valve prolapse (MVP). Most
people who have the condition are born with it. However, complications from
MVP, such as
arrhythmias
(irregular heartbeats) and
infective endocarditis, are rare.
In the past, some people who had MVP were given
antibiotics before dental work and surgeries to prevent infective endocarditis.
New research suggests that people who have MVP don't need antibiotics before
such procedures.
However, if you've had valve repair or replacement,
you may still need antibiotics before dental work and surgeries. Talk to your
doctor about whether you need these medicines.
Living With Mitral Valve Prolapse
Most people with mitral valve prolapse (MVP) have no
symptoms or problems, need no treatment, and are able to lead normal, active
lives. Symptoms and complications, when present, most often can be controlled
with medicines.
Some people may need heart valve surgery to relieve
their symptoms and prevent complications. Rarely, MVP can result in
heart
failure,
arrhythmias
(irregular heartbeats), or
stroke.
Ongoing Health Care Needs
If you have MVP, you should:
- Check with your doctor if your symptoms get
worse.
- Try to prevent
infective endocarditis (an infection of the surface of the
mitral valve flaps).
- Tell your doctors and dentists that you have
MVP. Floss and brush your teeth regularly. Gum infections and tooth decay can
cause endocarditis.
- Call your doctor if you have any signs of
infection, such as sore throat, general body aches, and fever.
- Take all medicines as prescribed, including
blood-thinning and
high
blood pressure medicines.
- Make healthy lifestyle choices.
- Avoid smoking and taking birth control pills,
which increase the risk for blood clots.
- Talk with your health care provider about how
much and what kind of exercise is right for you.
- Ask about any changes you need to make to
your diet.
Key Points
- Mitral valve prolapse (MVP) is a heart condition
in which one or both flaps of the mitral valve are floppy or thickened. These
abnormal valve flaps prolapse (bulge back) into the left atrium as the left
ventricle contracts. This prevents the valve from closing tightly and can allow
blood to flow backward through the valve. The backward flow of blood through
the valve is called mitral valve regurgitation.
- MVP is one of the more common heart valve
conditions. Most often, its a lifelong condition that a person is born
with. Most people with MVP have no symptoms or problems, need no treatment, and
are able to lead normal, active lives.
- Rarely, MVP can cause complications, such as
mitral valve regurgitation,
arrhythmias
(irregular heartbeats), and
infective endocarditis, a serious heart valve infection.
- The most useful test for diagnosing MVP is an
echocardiogram with Doppler
ultrasound.
- Complications and severe symptoms of MVP are
treated with medicines and sometimes with heart valve surgery. The preferred
surgery is mitral valve repair, but the mitral valve may need to be replaced
with a mechanical or biological valve.
- You can't prevent MVP. However, complications
from this condition are rare.
- If you have MVP, you should check with your
doctor if your symptoms get worse, get ongoing care, and take all your
medicines as prescribed.
Links to Other Information About Mitral Valve
Prolapse
Non-NHLBI Resources
Clinical Trials
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