Aortic valve sclerosis means that this valve has lost its flexibility without necessarily having a reduced opening.
The heart and its valves
The heart, the motor of life, has 4 valves that ensure the passage in one direction of blood from one heart chamber to another, or in other words, without the possibility of returning to the previous cavity.
Two of these valves are called the tricuspid valves and the other two are named atrioventricular valves. Tricuspid valves are the pulmonary valve and the aortic valve. They are composed of 3 leaflets, hence their name.
The pulmonary valve separates the right ventricle from the pulmonary artery and the aortic valve separates the left ventricle from the aorta.
The aortic valve
The aortic valve is made of three very thin leaflets ensuring a great flexibility. They are shaped like a ladle, which is why they are also called cupules.
Each of these leaflets is attached to the aortic ring at the base of the aorta. The rest of the leaflet is free and moves according to pressure variations on both sides of the valve. Thus, the valve opens when the pressure inside the heart exceeds the pressure in the aorta.
Opening and closing the aortic valve
Each heartbeat, divided into a contraction and relaxation, represents a cycle. The heart fills with blood during relaxation and ejects it during contraction.
When the heart contracts, the thin, flexible leaflets of the aortic valve open, leaving space for the blood to rapidly eject into the aorta. Then, the heart relaxes.
While the heart relaxes, blood that has been expelled into the aorta attempts a return to the ventricle. It is the suction effect caused by the relaxation of the heart returning to its original shape.
This attempt to return to the ventricle causes the opening of the cupules of the aortic valve. An image that describes this can be inverted parachutes that open. The return of the blood into the left ventricle is thus blocked.
Where does the loss of flexibility come from?
It has long been believed that sclerosis, or the loss of flexibility - or a calcification - of the aortic valve, was solely the result of mechanical stress imposed by each ventricular contraction.
Although this may trigger the entire aging process of the valve, it is now well proven that the biological phenomenon in the aortic valve is very similar to that of atherosclerosis.
An inflammatory process is the start
The sclerosis process comes from a fat deposit and the biological reactions that follow at the valve’s leaflet. These reactions activate successive inflammatory events, culminating in a loss of flexibility, thickening and even calcification of the leaflets.
This sclerotic process decreases the leaflets’ mobility and, with the evolution of the disease, may cause a narrowing of the orifice through which the blood is ejected. At this more advanced stage, we are talking about of aortic stenosis rather than sclerosis.
The factors promoting the sclerosis of the aortic valve are very similar to those of coronary heart disease. Thus, age, males, obesity, high blood pressure, diabetes, high cholesterol and smoking are all related to aortic sclerosis.
Age is by far the most important risk factor, with aortic sclerosis occurring in less than 10% of people under 60 and in 50% of people over 80.
Condition without symptoms
Aortic sclerosis is usually symptomless.
It is discovered by luck, in the majority of the time, during a medical examination.
The doctor hears a murmur while listening to the heart with his stethoscope or it is detected during a requested echocardiogram for another reason.
Possible progression to aortic stenosis
It is a disease that can eventually progress to aortic stenosis, or a narrowing of the aortic valve. The importance of this narrowing may show symptoms, if any.
After a diagnosis of aortic valve sclerosis without stenosis, current recommendations do not imply for specific follow-ups.
The doctor can repeat the echocardiogram, if some symptoms like prolonged breathlessness after effort appear.
Although aortic sclerosis does not present any symptoms, it is in fact the same pathological phenomenon as aortic stenosis. There is therefore a risk of progression to this disease of about 2% annually.
It is important to remember that people with aortic sclerosis can lead a normal life and that their prognosis is excellent.
Prevention: a priority
It must be kept in mind, however, that the process leading to sclerosis of the aortic valve is like coronary artery disease. Therefore, healthy life habits should always be adopted and put into practice.