The mitral valve, also called bicuspid valve (from the Latin cusp meaning spear point, or two-pointed valve), is a valve located at the level of the heart, connecting the left atrium to the left ventricle.

Location of the mitral valve. The mitral valve is located at the level of the heart. The latter is divided into two parts, left and right, each having a ventricle and an atrium. Some of these anatomical structures are interconnected by valves, including the mitral valve between the left atrium and the left ventricle (1).

Mitral valve structure. The mitral valve can be divided into two parts (2):

– the valve apparatus, consisting of:

• a fibrous ring, surrounding the valve
• valve leaflets, originating at the level of the fibrous annulus and made up of folds of the endocardium (1), the inner layer of the heart

– the subvalvular apparatus, consisting of:

• of tendon cords
• of tendon cords

Blood path. Blood circulates in one direction through the heart and the blood system. The left atrium receives oxygen-rich blood from the pulmonary veins. This blood then passes through the mitral valve to reach the left ventricle. Within the latter, blood then passes through the aortic valve to reach the aorta and be distributed throughout the body (1).

Opening / closing the valve. The mitral valve opens by pressure of the blood at the level of the left atrium and contraction of the latter. When the left ventricle is full and the pressure increases, the ventricle contracts and causes the mitral valve to close. This is in particular kept closed thanks to the papillary muscles.

Anti-reflux of blood. Playing an important role in the passage of blood, the mitral valve also prevents the backflow of blood from the ventricle to the atrium (1).

Valvular heart disease refers to all pathologies affecting the heart valves. The course of these pathologies can lead to a change in the structure of the heart with dilation of the atrium or the ventricle. The symptoms of these pathologies can in particular be a murmur in the heart, palpitations, or even discomfort (3).

• Mitral insufficiency. Also called valve leakage, it is the most common valve disease in adults. It is linked to a poor closing of the valve causing blood to flow back to the atrium. The causes of this condition are varied and can include age-related degeneration, infection or endocarditis.
• Mitral stenosis. Also called mitral valve narrowing, this valve disease corresponds to an insufficient opening of the valve preventing blood from circulating properly. The causes are varied and can include acute rheumatoid arthritis, infection or endocarditis.

Medical treatment. Depending on the valve disease and its progression, different drugs may be prescribed, for example to prevent certain infections such as infective endocarditis. These treatments can also be specific and intended for associated diseases (4).

Surgical treatment. In the most advanced valve disease, surgical treatment is frequently performed. Treatment can be either aortic valve repair or the replacement and placement of a mechanical or biological valve prosthesis (bio-prosthesis) (3).

Physical examination. First, a clinical examination is performed in order to observe the heart rate in particular and to assess the symptoms perceived by the patient such as shortness of breath or palpitations.

Medical imaging examination: A cardiac ultrasound, or even a doppler ultrasound can be performed. They can be supplemented by a coronary angiography, a CT scan, or an MRI.

Stress electrocardiogram. This test is used to analyze the electrical activity of the heart during physical exertion.

André Vésale, Belgian anatomist and doctor of the 5th century, gave the name of “mitral” to this valve in comparison with the shape of a miter, headgear of the bishops (XNUMX).