What causes narrowing of heart valves?
Narrowing of heart valves can occur at birth. Then it is called congenital narrowing of heart valves. Narrowing of heart valves is given the technical name ‘stenosis‘. Narrowing of aortic valve (valve between the left ventricle – lower muscular chamber of the heart – and the aorta – large blood vessel carrying oxygenated blood to the body) is known as aortic stenosis. Narrowing the valve between the left upper and lower chambers of the heart is known as mitral stenosis. Corresponding names on the right side of the heart are tricuspid stenosis and pulmonary stenosis.
An important cause of narrowing of heart valves in developing countries is rheumatic fever. Degeneration of valve structures by age can lead to narrowing of the aortic valve causing aortic stenosis. As time goes by, these valves can get calcified, with deposit of compounds containing calcium. Then it is called calcific aortic stenosis. Birth defect of the aortic valve in which it has only two cusps instead of the normal three is known as bicuspid aortic valve. Bicuspid aortic valve can degenerate earlier than normal aortic valve causing aortic stenosis. Valves can also get narrowed due to deposition of other materials in certain diseases (infiltrative disorders).