Heart defect: mitral prolapse (a dilated heart valve)

Our heart ensures that all parts of the body are supplied with oxygen and nutrients. The heart consists of 4 cavities, which are separated by valves. One of the heart valves is the mitral valve. If it widens and can therefore no longer close properly, blood flows back. If this valve is greatly dilated, it is called mitral prolapse. This can cause all kinds of complaints such as fatigue, dizziness and palpitations. What exactly does this heart defect mean and what are the symptoms?

The functioning of the heart

The heart is a muscle that is hollow on the inside and in adults is the size of a clenched fist. It pumps blood through the body, providing all tissues with oxygen and nutrients. The deoxygenated blood is pumped to the lungs to be re-oxygenated. Broadly speaking, the heart is made up of atria, chambers and heart valves.

Atria and ventricles

The 2 upper chambers in the heart are the right atrium and left atrium and the 2 lower cavities are the right ventricle and left ventricle. The chambers are also called ventricles. The atria receive the blood from the body. The left atrium receives oxygen-rich blood from the lungs. The right atrium receives deoxygenated blood from the rest of the body. Blood is pumped from the atria to the ventricles. The left ventricle pumps oxygen-rich blood into the body via the body artery, the aorta. The right ventricle pumps deoxygenated blood to the lungs.

Heart valves

The cavities in the heart are separated by valves. The valve between the left atrium and left ventricle is the mitral valve. This valve opens and closes with each heartbeat. The oxygen-rich blood from the lungs enters the left atrium. It then flows through the open mitral valve to the left ventricle. Then the valve closes and the aortic valve opens to transport blood to the body.

Mitral valve prolapse

If the mitral valve is greatly dilated, it is called mitral valve prolapse. Prolapse is the medical name for dilation. Now that the valve can no longer close properly, it will not close properly due to a contraction of the heart, causing blood to flow back to the left atrium. This usually involves small amounts of blood, so it sometimes takes a long time before the problem is determined.


There are often hardly any complaints with a mitral valve prolapse. Symptoms usually occur such as fatigue, palpitations, dizziness, migraine, low blood pressure, and mild cardiac arrhythmias. Sometimes there is pain in the chest and someone suffers from anxiety attacks. Fatigue is the most common complaint because oxygen-rich blood is pumped into the body less effectively. Fatigue is especially noticeable during exertion such as sports because your muscles need extra oxygen. There may be imbalances in the part of the nervous system that regulates the heart rate, the autonomic nervous system.


Mitral valve prolapse is usually a harmless condition. The palpitations are harmless and usually there are no obvious symptoms. If the condition does cause problems, you can choose, for example, beta-blockers to slow down the accelerated heart rhythm or antibiotics in the case of acute rheumatism. Beta-blockers are certain drugs that are used for, among other things, high blood pressure, certain heart complaints and increased eye pressure. In a small number of cases, cardiac arrhythmias are a reason for further investigation and treatment.


If the doctor listens with a stethoscope on the chest, an abnormality may be heard. A clicking sound is noticeable that begins soon after passing the left atrium. This is a clicking sound caused by back pressure from the mitral valve. This indicates blood leakage back into the left ventricle. Because it does not close properly, a kind of rushing sound can be heard when the blood flows back, immediately after the clicking sound of the valve.

Furthermore, a diagnosis can be made by means of echocardiography. This is the most common test to make the diagnosis. A recording of the heart rhythm can be made during this time using a 24-hour Holter monitor. In the meantime, the patient can continue with his daily activities. Sometimes it is decided to carry out this registration for a longer period, sometimes for a period of several weeks. Sometimes days may pass without any abnormalities in the heart rhythm.