26 November 2017
BICUSPID AORTIC VALVE
A bicuspid aortic valve is a congenital anomaly i.e. present at birth. It results in fact from a formation defect of the heart during pregnancy.
Present in 2% of the population
The aortic valve is located between the left ventricle and the aorta. It makes it possible for blood to leave the heart. Normally, the aortic valve is tricuspid, i.e. formed by three cusps. A bicuspid aortic has only two.
This anomaly is relatively frequent and is found in 2% of the population. It is more frequent in men.
Usually without any symptom
If the two cusps of the valve open and close normally, there will be no impact on the heart and thus no symptom.
Usually found by coincidence
A bicuspid aortic valve is usually found by coincidence, when people undergo echocardiography.
A heart murmur
For others, this congenital malformation of the aortic valve will be responsible for an abnormal noise (a murmur) heard with the stethoscope.
An echocardiogram ordered to elucidate that murmur will highlight the bicuspid aortic valve
The echocardiogram: the test of choice
The diagnosis is made during cardiac echocardiography. This test makes it possible to see the cusps, and to assess the presence of obstruction (stenosis) or leakage (insufficiency). This test can also assess the effects of the abnormal valve on the cardiac muscle.
A bicuspid aortic valve could leak, i.e. allow the return of blood from the aorta to the left ventricle. If that’s the case, it is called aortic insufficiency.
More prone to premature degeneration
A bicuspid aortic valve is more likely to be damaged prematurely.
The process could be secondary to chronic inflammation caused by the physical forces exerted on the two cusps.
Narrowing of the valve
Chronic inflammation can lead to calcium deposits, making the cusps more rigid. Its opening amplitude is reduced by the rigidity of the cusps. We refer to it as a stenotic valve.
A valve leak or regurgitation is also possible. Chronic inflammation and calcium deposits not only can make the cusps more rigid, but they can alter their shape, having for consequence the loss of the valve integrity.
A defective valve increases the workload of the heart
If the valve is narrowed or leaking, the heart will have to carry out an additional workload to pump blood to the organs. Patients could experience exertional shortness of breath, chest pains, dizzy spells or even loss of consciousness.
Certain patients may require cardiac surgery
When the stenosis or the regurgitation becomes too important, doctors will consider a surgery to repair or replace the valve.
Dilatation of the aorta
The presence of an aortic bicuspid valve is often associated with a dilatation of the aorta (an increase in diameter). The aorta is the major vessel that leaves the heart.
However, dilatation of the aorta can occur with other diseases, in the absence of stenosis or insufficiency of the aortic valve.
Dilatation of the aorta, when severe, may require a surgery to prevent rupture of the vessel.
Patients with aortic dilatation must ensure they always have their blood pressure under control and they must avoid strenuous exertion or training. High blood pressure and heavy exertion such as weight lifting can accelerate the dilation of the aorta.
A valve likely to be infected
The presence of a bicuspid aortic valve predisposes to infection within the heart. It is a rare infection that can be difficult to treat. We refer to it as bacterial endocarditis. This infection is likely to occur if there are bacteria present in the bloodstream.
A good oral hygiene is important
These bacteria generally come from the mouth. It is thus very important to have a very good dental hygiene and to visit the dentist on a regular basis.
It is not necessary any more to take antibiotics before visits to the dentist, as it was formerly recommended.
Follow-up by echocardiography
A periodic follow-up with echocardiography is necessary for people with a bicuspid aortic valve. This examination makes it possible to assess the valve performance while measuring the size of the aorta.
It also makes it possible to follow the evolution of a stenosis and/or a regurgitation of the valve.
Precaution during pregnancy
A complete assessment is necessary before pregnancy. It is very important to make sure that there is no stenosis or severe regurgitation BEFORE a pregnancy.