aortic valve

Last reviewed 01/2018

The aortic valve is the structure sited between the left ventricle and the aorta that permits blood flow in only one direction, from the former to the latter. Like the pulmonary valve, it has three half-moon shaped valve leaflets.

In diastole, the leaflets of the valve are tightly apposed and form a concavity with their sinuses that is bounded by their respective free margins. The ejected column of blood is maintained above the valve by the apposition of the leaflets. During this phase, blood leaves the left and right sinuses via the coronary ostia of the coronary arteries.

During systole, the valve leaflets move apart and the elasticity of the sinus walls permits the pressure wave to distend the diameter of the valve. The aperture of the valve becomes triangular in shape but the leaflets do not touch the sinus walls due to small vortices of blood flow which develop in the sinuses. This movement of blood within the sinuses is important to ensure that the leaflets do not adhere to the sinus walls, so rendering the valve incompetent.

Pathology of the aortic valve is relatively common e.g. congential abnormalities of the leaflets, rheumatic and infective damage.