What is Bicuspid Aortic Valve (BAV)?

A bicuspid aortic valve (BAV) is a common heart condition developed before birth. Normally, the aortic valve consists of three leaflets, also known as cusps or flaps, which open and close to regulate blood flow from the heart's left ventricle to the aorta.

In the case of a bicuspid aortic valve, two of the leaflets are fused together, resulting in a valve with only two functioning leaflets.

BAV can run in families so your cardiologist may recommend other family members also see a specialist. The cause of a bicuspid aortic valve is

not known. Experts do not think this is caused by anything that the mother has done during pregnancy.

It can occur alone, or associated with other defects affecting the left side of the heart such as mitral stenosis or coarctation of the aorta.

Effects and Symptoms

The job of the aortic valve is to open and allow blood to travel from the left ventricle, through the aorta and out to the rest of the body. An aortic valve with two leaflets may have the following effects:

1. It can work and function normally.
2. It may become stiff over time and cause a narrowing at the aortic valve (aortic stenosis). This can cause the left ventricle to squeeze harder to push blood through the valve.
3. It may become stiff and unable to close properly causing blood to leak back (aortic regurgitation) into the left ventricle. The leak introduces more blood for the left ventricle to pump through the valve or
4. The aortic valve may have some degree of both aortic stenosis and regurgitation. The degree of narrowing or leaking is classified into mild, moderate or severe.

Diagnosis

A BAV can be recognized when a murmur or click is heard during a physical examination. Most patients with BAV do not have any symptoms. Some children are found to have BAV by screening because a family member was diagnosed with BAV. Diagnosis is confirmed by echocardiogram.

Management and Treatment

Everyone with a BAV should have regular follow up with an echocardiogram. The frequency of follow up appointments will depend on many factors including changes in the aortic valve over time and changes it may cause on the left ventricle or the aorta. 

BAV with aortic stenosis or aortic regurgitation are managed accordingly.

There are no restrictions for patients with mild narrowing at the aortic valve. If there are signs either enlargement of the ascending aorta or signs of moderate narrowing of the aortic valve along with changes to the walls of the heart, or arrhythmias, then exercise guidelines should be followed. 

There is no need for antibiotics prior to dental procedures, but good dental hygiene is important.

Surgery

Cardiac catheterization or surgical intervention are required for those with significant aortic stenosis, regurgitation or dilation in the aorta that progresses over time.

Adult and Adolescent Management

Continued follow up and monitoring are required throughout adolescence and adulthood to monitor changes in the valve, left ventricle and aorta. Cardiac catheterization and surgical intervention may be needed as an adult for significant changes.

Pregnancy and BAV

Patients with bicuspid aortic valve should meet with their cardiologist before or at the beginning of pregnancy as there is a risk of aortic dilation and aneurysm formation.