Journal of Birth Defects

The aorta is the main artery that carries blood out of the heart to the rest of the body. Blood flows out of the heart and into the aorta through the aortic valve. In aortic stenosis, the aortic valve does not open fully. This decreases blood flow from the heart. As the aortic valve narrows, the left ventricle has to work harder to pump blood out through the valve. To do this extra work, the muscles in the ventricle walls become thicker. This can lead to chest pain. As the pressure continues to rise, blood may back up into the lungs. Severe aortic stenosis can limit the amount of blood that reaches the brain and the rest of the body. Aortic stenosis may be present from birth (congenital), but most often it develops later in life. Children with aortic stenosis may have other conditions present from birth. Aortic stenosis mainly occurs due to the buildup of calcium deposits that narrow the valve. This is called calcific aortic stenosis.

The problem mostly affects older people. Calcium buildup of the valve happens sooner in people who are born with abnormal aortic or bicuspid valves. In rare cases, calcium buildup can develop more quickly when a person has received chest radiation (such as for cancer treatment). Another cause is rheumatic fever. This condition can develop after strep throat or scarlet fever. Valve problems do not develop for 5 to 10 years or longer after rheumatic fever occurs. Rheumatic fever is becoming rarer in the United States. Aortic stenosis occurs in about 2% of people over 65 years of age. It occurs more often in men than in women.