Causes

The aortic valve is one of four valves that control blood flow through the heart. It separates the heart's main pumping chamber (left ventricle) and the main artery that supplies oxygen-rich blood to your body (aorta). The valve has flaps (cusps or leaflets) that open and close once during each heartbeat.

In aortic valve regurgitation, the valve doesn't close properly, causing blood to leak back into the heart's main pumping chamber (left ventricle). As a result, the left ventricle holds more blood, possibly causing it to enlarge and thicken.

At first, the larger left ventricle helps maintain good blood flow with more force. But eventually these changes weaken the left ventricle — and your heart overall.

Aortic valve regurgitation usually occurs gradually, but it can develop suddenly when caused by a valve infection. Any condition that damages the aortic valve can cause regurgitation. However, you can develop aortic valve regurgitation without any known risk factors.

Causes of aortic valve regurgitation include:

• Congenital heart valve disease. Some people are born with an aortic valve that has only two cusps (bicuspid valve) or fused cusps rather than the normal three separate cusps. Sometimes a valve may only have one cusp (unicuspid) or four cusps (quadricuspid), but this is less common.

  These congenital heart defects put you at risk of developing aortic valve regurgitation at some time in your life. If you have a parent or sibling with a bicuspid valve, it increases the risk that you may have a bicuspid valve. However, you can have a bicuspid valve even if you don't have a family history of the defect.

• Narrowing of the aortic valve (aortic stenosis). Calcium deposits can build up on the aortic valve as you age, causing the aortic valve to stiffen and become narrow. This condition, called aortic stenosis, prevents the valve from opening, causing a blockage. Aortic stenosis may also prevent the valve from closing properly.
• Inflammation of the lining of the heart's chambers and valves (endocarditis). This life-threatening condition is usually caused by infection. It can damage the aortic valve.
• Rheumatic fever. Rheumatic fever is a complication of strep throat and was once a common childhood illness in the United States. It can cause the aortic valve to become stiff and narrow (stenosis), causing blood to leak. If you have an abnormal heart valve due to rheumatic fever, it's called rheumatic heart disease.
• Other diseases. Other rare conditions can enlarge the aorta and aortic valve and lead to regurgitation, including Marfan syndrome, a connective tissue disease. Some autoimmune conditions, such as lupus, also can lead to aortic valve regurgitation.
• Tear or injury of the body's main artery (aorta). A traumatic chest injury or aortic tear (dissection) may cause backward flow of blood through the aortic valve.