Aortic regurgitation pathophysiology
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Associate Editor-In-Chief: Varun Kumar, M.B.B.S.; Lakshmi Gopalakrishnan, M.B.B.S.
Aortic Valve Disease
A full list of causes of aortic regurgitation can be found in the differential diagnosis section below.
One of the most common causes of aortic valvular disease in the past has been rheumatic fever in which case the aortic cusps are infiltrated with fibrous tissue. This then leads to retraction of the cusps and prevents their apposition during diastole. The cusps may also fuse and this may cause a component of aortic stenosis. It is therefore not uncommon for these patients to have mixed aortic regurgitation and aortic stenosis. Often these patients will have involvement of the mitral valve as well.
In the modern era, a more common cause of acquired aortic valve regurgitation is degenerative disease of the aorta and aortic valve in which case there is calcification and fibrosis of the cusps. As is the case with rheumatic fever, there is similar retraction of the cusps that results in aortic insufficiency.
A third not uncommon cause of acquired aortic regurgitation is infective endocarditis. In this disease state, regurgitation develops as a result of a hole or perforation that develops in the leaflet, or alternatively the cusps may not oppose each other due to a vegetation lying between the cusps which prevents their apposition.
A final not uncommon cause of acquired aortic insufficiency is trauma in which case there is distortion of the valve architecture leading to failure of the cusps to oppose.
Congenital conditions such as congenital bicuspid aortic stenosis or a ventricular septal defect can also result in aortic insufficiency.
Aortic Root Disease
Aortic root disease as a cause of aortic insufficiency has overtaken acquired forms of valvular disease and congenital forms of valvular disease as the leading cause of aortic regurgitation. The following is a list of those conditions that lead to dilation of the aortic root and thereby cause aortic insufficiency: