Aortic stenosis is a heart defect characterised by the narrowing of the aortic valve opening. In turn, this narrowing restricts the flow of blood from the left ventricle to the aorta. Sometimes aortic stenosis does not always produce symptoms, however, symptoms may include breathlessness, chest pain (angina), palpitations and a heart murmur. It can result either as a congenital birth defect or in ageing patients where scarring and calcium deposits build up in the valve opening. Treatment may require surgical valve repair or replacement.