Aortic stenosis is most commonly caused by calcium buildup on the leaflets of the aortic valve – which tends to occur as people get older. The other cause stems from birth defects during which two leaflets are fused into one – meaning the “tricuspid” aortic valve becomes a “bicuspid” aortic valve.
A Answers (4)
Johns Hopkins Medicine answered
Riverside Heart and Vascular Center answered
Some people with aortic stenosis (AS) were born with a problem with the aortic valve in their heart. The valve may have one or two cusps instead of three. The cusps may be deformed and only partially close.
As people get older, calcium can build up and make the cusps thicker and stiffer. This leads to AS.
An infection called rheumatic fever may also cause heart valve damage and AS.
Aortic stenosis (narrowing of the aortic valve) is a common condition that may be present at birth or develop later in life. There are several reasons why people develop aortic stenosis:
Congenital Aortic Stenosis:
- Bicuspid aortic valve disease is a defect that occurs during the formation of the aortic valve in the uterus. In bicuspid aortic valve disease, the valve has only two leaflets; normal hearts have three leaflets. This abnormality occurs in about 2% of the population. It affects men more frequently than women. It is also associated with other congenital abnormalities such as coarctation (narrowing) of the aorta, aortic aneurysm (bulging of the aorta’s wall) and Turner syndrome (a female genetic condition). Bicuspid aortic valve disease can lead to aortic stenosis over time.
- Subaortic stenosis is seen in 5% to 10% of people with aortic stenosis. Normally, a ridge of tissue partially or completely surrounds the area just below the aortic valve. This area is referred to as the left ventricular outflow tract (LVOT). Sometimes, a membrane is seen across the LVOT. This additional tissue causes a jet of blood to hit a portion of the aortic valve leaflets. This leads to leaflet thickening and eventual narrowing of the aortic valve.
- Supra-aortic stenosis is an uncommon condition with narrowing above the aortic valve. The aortic valve leaflets are thick, which causes blood to leak back into the left ventricle. The coronary arteries begin just above the aortic valve. They can become damaged as a result of the high-pressure blood flow past the narrowed area. Supra-aortic stenosis is often associated with Williams syndrome, a rare genetic disorder.
Calcification: Calcium is a mineral that is normally found in blood. With age, calcium deposits build up on the aortic valve leaflets. This process causes the leaflets to stiffen, making them less mobile. For some people, this process affects the opening of the valve, leading to a narrow passage for blood to flow through. This condition is generally seen in patients older than 60 and occurs in men more frequently than women. People with a bicuspid aortic valve are especially prone to the calcification process.
Rheumatic Fever: Prior to the advent of antibiotics, many people developed rheumatic fever as a child or young adult after an episode of strep throat or scarlet fever. This disease often affected the aortic valve, causing stenosis 10 or more years later. Rheumatic fever is now rarely seen in the U.S.
SCAI answeredAortic stenosis can be caused by fusion of the flap-like parts, called leaflets, that make up the aortic valve. This valve allows oxygen-rich blood to exit the left side of the heart and reach the aorta. Most people have three leaflets in the aortic valve, which opens to allow the blood to flow out of the left side of the heart into the aorta and closes to prevent blood from leaking backward. Some may only have two functioning leaflets. When the leaflets fuse in aortic stenosis, they block the opening to the aorta and reduce blood flow, making the heart pump harder to move blood out to the body.
Aortic stenosis can also occur when the valve is abnormal from birth or can develop due to deposition of calcium on the leaflets over time.