Mitral Valve Prolapse

What Is the Mitral Valve?

To understand mitral valve prolapse, it's helpful to review some basics about the way a healthy heart works.

• The heart is made up of four distinct chambers: two atria (the two upper chambers) and two ventricles (the two lower chambers).
• During circulation, blood flows from all over the body into the heart's right atrium.
• From there the blood travels to the right ventricle, which pumps the blood to the lungs to receive oxygen.
• Once the blood has been infused with oxygen, it returns from the lungs to the heart's left atrium.The oxygen-rich blood then passes into the left ventricle, which pumps it out to the body through a large blood vessel known as the aorta.

The mitral valve is located between the left atrium and the left ventricle and helps control the flow of blood as it passes from the left atrium into the left ventricle. The valve has two flaps of tissue — known as leaflets — that open and close together like a pair of swinging doors. Each time the heart beats, the left ventricle pumps blood out to the body and the flaps of the mitral valve swing shut to prevent the blood in the ventricle from flowing backward into the left atrium.

In cases of MVP, one or both of the mitral valve's flaps bulge back into the atrium when they are shut, a bit like a balloon. This may occur because one of the flaps is abnormally shaped or a little too large.

In some cases, when the flaps do not close evenly, blood is allowed to leak back into the left atrium. This is called mitral regurgitation. A tiny amount of mitral regurgitation is normal. In some cases, there's more leakage, which can cause a heart murmur a whooshing sound between the normal lub-dub of the heartbeat. (Because of these sounds, MVP is sometimes called click-murmur syndrome, floppy valve syndrome, or balloon mitral valve.)

In most cases, the cause of MVP is unknown. Sometimes kids are born with the condition. In other cases, it develops after some sort of inflammatory condition, like endocarditis, an inflammation of the inner lining of the heart, or rheumatic fever, an inflammation that can affect the joints and the heart.

MVP may be diagnosed in people who have other health conditions that affect the body's connective tissue, such as Marfan sndrome. Some research has shown that kids with MVP may be more likely to also have an arrythmia, an irregular heartbeat.

Signs and Symptoms

Many people with MVP have no symptoms. In some cases, though, the flaps of the mitral valve make a clicking sound when they close. A doctor may be able to hear this noise when listening to the heart with a stethoscope. Someone who has MVP and mitral regurgitation may also have a heart murmur, a sound caused by some blood moving backward into the left atrium. When a click and a murmur are heard together, the click happens first, as the flaps close, followed by the murmur as the blood leaks back into the atrium through the improperly closed valve.

Kids with MVP also may experience:

• dizziness or lightheadedness
• fatigue
• shortness of breath or trouble breathing after exertion
• a feeling that the heart is skipping beats or beating very quickly
• chest pain that comes and goes

The chest pain is often sharp but it can vary from person to person. Learn to recognize the symptoms, and call your doctor if your child has chest pain that:

• consistently occurs during physical exertion (exercise or sports)
• creates pressure and a crushing sensation
• occurs with other symptoms (palpitations that last more than a few seconds, dizziness, fainting, or shortness of breath)

Diagnosis and Treatment

In most cases, MVP is diagnosed during a routine exam when a doctor listens to the heart with a stethoscope and hears a different sound. If the doctor hears a click or a murmur that indicates MVP, your child may be referred to a pediatric cardiologist, a doctor who specializes in diagnosing and treating heart conditions in kids.

The cardiologist will perform a thorough physical exam and listen to the heart. Then he or she may order tests — including an echocardiogram (echo) and an electrocardiogram (EKG or ECG) — to find out what's causing the sound. An echo uses sound waves to create a picture of the heart and its blood flow, and an EKG records electrical activity in the heart. If a child has MVP, the bulging valve flaps will probably be seen on the echo when the heart beats.

Kids who are diagnosed with MVP usually require no medical treatment. In some cases where MVP causes significant regurgitation, blood pressure medication is prescribed to control how hard the heart muscle must work. (With blood leaking back into the atrium, the heart works harder to pump the normal amount of blood out to the body.) A child who has an arrhythmia in addition to MVP may need to take medicine to help regulate the heart's rhythm. In rare cases, surgery may be done to repair a very leaky mitral valve.

Caring for a Child With MVP

Kids with MVP who have no other medical conditions typically require no special care. A child with MVP who plays competitive sports will be able to continue doing so as long there's no mitral regurgitation or active symptoms from the MVP. A child who does have regurgitation or symptoms will have to be cleared by the doctor to participate in sports. This may involve some additional tests.

Although any heart condition can be frightening, mitral valve prolapse likely will not have any impact on your child's everyday life and activities. If you have any questions or concerns, speak with your doctor.