Aortic valve stenosis (more commonly known as aortic stenosis) is a narrowing of the aortic valve. The aortic valve controls the blood flow between the heart's main pumping chamber and main artery (aorta).
Aortic stenosis occurs when the aortic valve becomes narrow and obstructs the flow of blood from the heart to rest of the body. When the aortic valve gets very narrow, the heart has to work harder to pump the blood around the body. As a result, the heart muscle gets thicker, stiffer and, over time, weaker. This weakness of the heart muscle is called heart failure.
When symptoms occur, they often start with exertion and include:
Once symptoms develop, they often progress and, if not diagnosed and treated, can cause severe heart problems. Over time, if the heart muscle gets very weak and there is heart failure, symptoms can also include swelling in the ankles, shortness of breath when resting, and an inability to lie flat.
There are three main causes of aortic stenosis.
The first and most common cause is buildup of calcium on an otherwise normal aortic valve that occurs with age.
Second, about 2% of people are born with an aortic valve with an abnormal valve structure. Normal aortic valves have three leaflets, also called cusps. In a small portion of the population, the aortic valve has two cusps (bicuspid aortic valve) and, more rarely, one or four cusps. In these cases, the blood flows more roughly over the valve and causes calcium buildup and narrowing of the valve (stenosis) at an earlier age (50 to 60 years old, instead of 70 to 80 years old).
Third, a less likely cause of aortic stenosis is inflammation caused by rheumatic heart disease, a condition that is more common in underdeveloped countries.