What is the Mitral Valve

According to WebMD, “the mitral valve lies between the left atrium and the left ventricle.” The mitral valve allows blood to flow from the left atrium into the left ventricle. It closes to prevent the back flow of blood into the left atrium during ventricular contraction.


The heart has four chambers, which consist of two atria and two ventricles.

Each side of the heart has an atrium above and a ventricle below.


There are four heart valves, namely:

The tricuspid valve between the right atrium and the right ventricle.

The pulmonary valve between the right ventricle and the pulmonary artery.

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

The aortic valve between the left ventricle and the aorta.


Blood circulating throughout the body goes into the right side of the heart, into the right atrium then enters the right ventricle through the tricuspid valve.

From there it goes to the lungs to be oxygenated.

The oxygenated blood goes to the left atrium and through the mitral valve into the left ventricle. This oxygenated blood is then pumped out into the body.


As previously mentioned the mitral valve allows blood to flow from the left atrium into the left ventricle. A normal functioning mitral valve allows blood to flow in one direction only, (from the atrium to the ventricle below.) When the heart relaxes in between beats, the two flaps of the mitral valve opens and allow blood to flow from the atrium into the ventricle. It then closes to prevent blood from the ventricle returning to the atrium.

In an impaired mitral valve the flap malfunctions. It does not close adequately causing blood to leak back into the left atrium. This is called mitral regurgitation. Mitral regurgitation may be due to the flaps being too big, too floppy or they maybe incorrectly shaped. This condition is called Mitral Valve Prolapse.

Mitral Valve Prolapse is one of the most common heart valve condition affecting 5% – 10% of the world’s population.

It is usually due to a congenital defect. An illness such as rheumatic fever or to an endocarditis infection of the heart muscles.

Most people with this condition have no signs and symptoms and are not aware that they have a prolapsed valve. They have no regurgitation. They usually have no problem and will need no treatment if and when it is discovered.

Others people with a Mitral Valve Prolapse will exhibit the following signs and symptoms.



Fainting Spells.


Chest Pains

Out of breathe during exercise.

Excessive tiredness

Skipped heartbeats

Experience fast beating heart rate.

Mitral Regurgitation can lead to changes in the size of the heart.

Higher pressure in the left atrium and lungs.

Increase risk of heart valve infection.

Heart failure

Patients without symptoms that know they have prolapsed mitral valve maybe checked every few years. Patients with regurgitation will be checked annually.

It is extremely important that if you have a prolapsed mitral valve that you must inform your doctor and/or dentist when undergoing any procedure that may introduce bacteria into your blood stream. Such as, dental work, colonoscopy, gynecological, minor surgery and urological procedures. Your doctor or dentist will prescribe a prophylactic or preventative course of antibiotic prior to the procedure. This is to prevent the occurence of an infection that may cause endocarditis (infection of the heart muscles) a rare but serious condition.

The good news is that most people with a prolapsed mitral valve can live a normal, active, healthy and happy life.