Mitral valve prolapse

Symptoms and causes

Mitral (MY-trul) valve prolapse is a common type of heart valve disease. It affects the valve between the two chambers on the left side of the heart. The mitral valve has flaps, called leaflets, that should open and close to keep blood flowing in the right direction. In mitral valve prolapse, one or both flaps are floppy. They puff out backward like a parachute each time the heart squeezes. This can change how blood flows through the heart.

Sometimes mitral valve prolapse causes blood to leak backward across the valve. When this happens, the condition is called mitral valve regurgitation.

Usually, mitral valve prolapse doesn't need treatment. But some people may need surgery, especially if the condition causes a major change in blood flow.

Other names for mitral valve prolapse are:

• Barlow syndrome.
• Billowing mitral valve syndrome.
• Floppy valve syndrome.
• Mitral prolapse.
• Myxomatous mitral valve disease.

Mitral valve prolapse and regurgitation

The mitral valve separates the two left heart chambers. The upper left heart chamber is called the left atrium. The bottom left chamber is called the left ventricle. In mitral valve prolapse, the mitral valve flaps bulge backward into the upper left heart chamber. Sometimes mitral valve prolapse causes blood to leak backward into the left atrium. If this happens, the condition is called mitral valve regurgitation.

Symptoms of mitral valve prolapse may happen when blood starts to leak backward through the valve. This is called regurgitation. Symptoms may be mild and start slowly. They may include:

• A racing or irregular heartbeat. This symptom may happen with or without mitral regurgitation.
• Trouble breathing.
• Shortness of breath, especially during exercise or when lying flat.
• Feeling very tired.

Symptoms can vary from person to person. Many people don't notice symptoms.

If you have symptoms of mitral valve prolapse, make an appointment for a health checkup. Many other conditions can cause similar symptoms. Your healthcare professional may refer you to a doctor trained in heart diseases, called a cardiologist.

Call 911 or your local emergency number if you have sudden or unusual chest pain or think you're having a heart attack.

To understand the causes of mitral valve disease, it may help to know how the heart works.

The mitral valve is one of four valves in the heart that keep blood flowing in the right direction. Each heart valve has flaps, called leaflets or cusps. The name of the flap depends on the valve. The mitral valve's flaps are called leaflets. The flaps open and close once during each heartbeat. If a valve flap doesn't open or close properly, less blood moves out of the heart to the rest of the body.

In mitral valve prolapse, the valve flaps are stretched out and floppy. They puff out backward like a parachute into the left upper heart chamber each time the heart squeezes.

Mitral valve prolapse falls into two general categories, depending on the cause.

• Primary mitral valve prolapse is a change or thickening in the tissue of the valve flaps. But the person doesn't have a connective tissue disease. Primary mitral prolapse may sometimes run in families.
• Secondary mitral valve prolapse is linked to another health condition, such as a connective tissue or heart condition present at birth.

Anyone can get mitral valve prolapse. Women are more likely than men to have mitral valve prolapse. But men with mitral valve prolapse are more likely to have a significant leaky valve that causes a condition called regurgitation. This leak may need surgery to fix.

Some medical conditions may raise the risk of mitral valve prolapse, including:

• Ebstein anomaly, a rare heart condition present at birth.
• Brittle bone disease, also called osteogenesis imperfecta.
• Graves' disease, a type of thyroid disease.
• Connective tissue conditions, including Ehlers-Danlos syndrome, Marfan syndrome and pseudoxanthoma elasticum.
• A sunken breastbone, called pectus excavatum.
• Duchenne muscular dystrophy.
• Eating disorders such as anorexia nervosa and bulimia.

Possible complications of mitral valve prolapse are:

• Mitral valve regurgitation. The mitral valve flaps don't close tightly. Blood flows backward when the valve is closed, making it harder for the heart to pump blood. Mitral valve prolapse is the main cause of mitral valve regurgitation.
• Irregular heartbeats, called arrhythmias. Irregular heartbeats can happen if you have mitral valve prolapse with or without mitral valve regurgitation.