The Aortic Valve
The normal aortic valve has 3 leaflets and is situated start of the aortic root in the aortic annulus. Each of the valve leaflets sited in a small swelling in the aorta called the sinus of Valsalva.
For individuals with bicuspid aortic valve disease there are only 2 valve leaflets. There several anomalies that causes a bicuspid valve, the most common being the fusion of the right and left valve leaflets resulting in 2 unequally sized valve leaflets.
Bicuspid aortic valve is the most common congenital heart disorder and affects between 0.5% and 2% of the adult population. Males are twice as likely to have a bicuspid aortic valve than females. First-degree relatives of someone with a bicuspid aortic valve are 10 times more likely to have a bicuspid aortic valve than the general population.
Importance of bicuspid aortic valve
Bicuspid aortic valve may lead to several conditions requiring valve replacement. The valve can become stenotic (narrowed) or incompetent (leading to backflow of blood into the heart)
Bicuspid aortic valve is strongly associated with dilation of the ascending aorta (for more information regarding the anatomy of the aorta click here) with up to 50% of patients with bicuspid aortic valve developing aortic dilation. The recognition of this aortic dilation is important and treatment is offered to prevent and important complication of aortic dilation – aortic dissection (click on the links for more information on aortic aneurysm and aortic dissection)
What are the symptoms of a bicuspid aortic valve?
The symptoms that can develop relate to the valve function and dilation of the aorta. The presence of any symptoms should prompt a review by your doctor.
Symptoms related to valve function include:
- Chest pain, particularly on exertion
- Irregular heart rhythms
- Shortness of breath
If sudden and severe chest pain develops, this could represent a medical emergency such as aortic aneurysm rupture or aortic dissection. This requires urgent presentation at an emergency department.
How is bicuspid aortic valve diagnosed?
The initial diagnosis is commonly made using a transthoracic echocardiogram
Other investigations you may be referred for to assess the size of the aorta include:
- CT aortagram
- MRI angiogram
How is bicuspid aortic valve managed?
Once a bicuspid aortic valve is diagnosed the management depends on the valve function and the size of the aorta.
Risk factors known to increase the rate of aortic dilation are managed these include:
- Smoking cessation
- Management of high blood pressure
- Avoidance of strenuous exercise
- Management of high cholesterol
Close surveillance of people with a bicuspid aortic valve involves regular assessment with an echocardiogram, CT aortagram or MRI angiogram. An operation may be offered if the size of the aorta or rate of growth is at a level that the risk of complications such as aortic dissection is too high.
Pregnancy may lead to an increase risk of complication in individuals with a known bicuspid aortic valve and dilated aorta. A discussion with your cardiologist should be undertaken prior to a planned pregnancy to reduce the chance encountering problems if you have a bicuspid aortic valve.
Verma S, Siu SC. Aortic Dilatation in Patients with Bicuspid Aortic Valve. New England Journal of Medicine. 2014;370(20):1920-9.
Siu SC, Silversides CK. Bicuspid Aortic Valve Disease. Journal of the American College of Cardiology. 2010;55(25):2789-800.
Broberg CS, Therrien J. Understanding and treating aortopathy in bicuspid aortic valve. Trends in Cardiovascular Medicine. 2014 December 17 pii: S1050-1738(14)00242-4. doi: 10.1016/j.tcm.2014.12.006. [Epub ahead of print]