What is mitral valve prolapse?

Mitral valve prolapse is a disease of the heart valve that rarely causes symptoms. However, mitral valve prolapse can lead to a leak in the heart valve

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What is mitral valve prolapse?

The mitral valve is one of the four heart valves. Doctors speak of mitral valve prolapse when parts of this heart valve bulge beyond a certain amount into the left atrium during the pumping action of the heart.

"Around one to two percent of the population are affected by mitral valve prolapse," says Professor Markus Haass, chief physician at the Theresienkrankenhaus Mannheim, an academic teaching hospital at Heidelberg University.

Mitral valve prolapse can occur at any age, but appears to be less common in children and adolescents under 16 years of age.

Where is the mitral valve located?

The mitral valve is located between the left atrium and the left ventricle and supports the heart in efficiently performing its main task: to pump blood that has been oxygenated in the lungs through the left atrium into the left ventricle and from there into the body.

The mitral valve sits between the left atrium and the left ventricle

© W & B / Szczesny

The heart valves are used so that the blood always flows forwards and not backwards while the heart is pumping. Like valves, they prevent backflow.

The mitral valve opens when blood flows from the left atrium into the left ventricle and closes when the ventricle subsequently contracts to force the blood into the main artery.

Its name can be traced back to its curved shape: it resembles a bishop's cap, called a miter. The mitral valve consists of an anterior and posterior valve leaflet that is suspended from tendon threads. The tendon threads in turn arise from protrusions of the heart muscle in the left ventricle - the so-called papillary muscles.

With mitral valve prolapse, parts of a leaflet, an entire leaflet, or even both leaflets can bulge into the left atrium.

What are the causes of mitral valve prolapse?

Mitral valve prolapse is usually the result of a connective tissue disorder. The reasons for this are largely unknown. Genetic factors seem to play a role.

In some cases, mitral valve prolapse develops as part of hereditary connective tissue diseases such as Marfan's syndrome. The result is an enlargement, overstretching, loosening or thickening of the valves and tendon threads.

However, prolapse can also occur after a heart attack - for example, if one of the papillary muscles from which the tendon threads of the mitral valve originate has been damaged.

Does a mitral valve prolapse cause symptoms?

The bulges usually do not cause any complaints. Some patients turn to the doctor because their heart seems to trip every now and then. "But perceptions of irregular heartbeat called palpitations are not a cause for undue concern in mitral valve prolapse," says Haass.

Anyone who experiences cardiac arrhythmias should still have them checked by a doctor - because they can also have other causes. Some arrhythmias require treatment.

How does the doctor make a diagnosis?

Because mitral valve prolapse usually does not cause any symptoms, the diagnosis is usually an incidental finding. A characteristic heart murmur is noticeable when listening. "In the heart ultrasound, the echocardiography, the bulging of the valve leaflets and in some cases a thickening of the free edges of the mitral valve leaflets can be seen," says Haass. Insufficiency can be visualized with the help of a so-called Doppler echocardiography.

Possible consequence: leaky heart valve

Even if the mitral valve prolapse itself is usually unproblematic and hardly noticeable, those affected should not take the diagnosis lightly. Because a sick sail can bulge more and more over time. An overloaded or altered tendon thread can tear off, so that at some point the valve no longer closes completely - it becomes leaky. Doctors then speak of mitral regurgitation.

This leakage causes blood to flow back into the left atrium during the pumping action of the left ventricle. This means a constant overhead for the heart - like when a perforated bucket is to be filled with sand. Depending on how much the cusps and tendon threads are changed, such an insufficiency can be stronger or weaker.

Typical symptoms of mitral valve regurgitation are rapid fatigue during physical exertion and dizziness, often associated with shortness of breath and poor performance.