25 June 2018
We find two valves that separate the atrium ventricles.
They are called atrioventricular valves.
On the right side, it is the tricuspid, and on the right, it is the mitral valve.
The mitral device
The mitral valve is made of anulus fibrosis from the cardiac and skeletal muscles, two leaflets, myocardium and muscular pillars from the bottom of the left ventricle.
All these structures form the mitral apparatus.
Like a sailboat
We can compare the mitral system to a sailboat. We have the mast, the ropes that connect the sail to the structures and the sail itself.
The two leaflets are attached all around the fibrous ring. The free edges of these leaflets are not smooth. These edges form extensions much like a short net. From this net, ropes are formed which are attached to muscular pillars at the bottom of the left ventricle.
This configuration allows the valves to be sealed.
Contraction of the ventricles from the bottom towards the top
The electrical system of the heart ensures a contraction of the ventricles from the bottom to the top.
The pressure generated by the contraction of the left ventricle pushes the blood from the bottom to the top and, in doing so, closes the mitral valve.
Closure of the normal mitral valve
When the mitral valve closes normally, the leaflets stick together. The ropes hold the leaflets and prevent them from falling back into the left atrium.
The mitral valve then forms a barrier, preventing the blood from returning to the atrium; the only possible way out for the blood is through the aortic valve.
Mitral prolapse occurs when, at closure, the mitral valve leaflets collide with one another. A bulge forms towards the left atrium.
In some cases, it can be said that the mitral leaflets “pull the tongue” of the left atrium.
Most common valvular abnormality
Mitral prolapse is the most common valvular abnormality. It is present in about 2% of the population.
Anomaly of the mitral apparatus
We can speak of anomaly when one or both leaflets are too big; or that the ropes of the valve are too long or damaged.
The cause of damaged cordage is still obscure. We speak of "myxomatous degeneration" when these ropes gradually lose their strength or resistance.
There is a broad spectrum of type of mitral prolapsed
There is a great variability of mitral prolapse.
The spectrum of mitral prolapse varies from an almost normal form to a severe form with valve leakage or the loss of the main function of the valve, which is to prevent blood from returning to the left atrium.
In its lightest form, the leaflets of the valve protrude into the left atrium, but the valve remains sealed, does not leak, and does not allow blood to pass to the left atrium.
Loss of tightness of the mitral valve
Mitral prolapse is the most common cause of a leaking mitral valve.
When the mitral valve is leaking, we refer to it as insufficiency or mitral leakage that can be classified as mild to severe depending on the amount of blood returning to the left atrium.
It is quite possible that the mitral prolapse never shows any leakage from the valve.
In cases where the mitral prolapse leaks, it may gain in importance over years.
In the case of a severe leak, that is, a large amount of blood flowing to the left atrium, there may be an impact on other cardiac structures.
These effects include enlargement of the left atrium, dilation of the left ventricle, and deterioration of its contraction power.
General symptoms associated ... myth or reality
In the past, mitral prolapse was associated with rather general symptoms, especially in women, often described by unrelated chest pains, varying in duration, with palpitations, shortness of breath, and headaches.
The important thing is the presence or not of a mitral leak
With a more scientific perspective, we cannot conclude that vague symptoms are associated with the presence of mitral prolapse.
It is the presence or absence of a mitral leak that matters.
Patients with severe leakage, symptoms such as fatigue or shortness of breath may appear.
In general, good oral hygiene is recommended.
There is no indication nowadays as to taking antibiotics before going to the dentist.
In cases where a mitral leak is present, a periodic echocardiography control is done to monitor the evolution of this leak and its repercussions on the rest of the heart.
In severe mitral insufficiencies, surgery to repair the mitral valve or to replace it with another metallic or biological valve may be necessary for severe mitral insufficiency with symptoms that limit daily activity
It is important to remember that the majority of mitral valve prolapses never develop significant mitral leakage.