Incidence and Pathology of Aortic Regurgitation.

Aortic regurgitation (AR) is the third most common valvular heart disease, with its prevalence and severity increasing with age. AR can arise from degenerative, congenital, inflammatory and infectious aetiologies, manifesting as primary AR with intrinsic leaflet disease, secondary AR due to aortopathy or annular dilatation, or a combination. Furthermore, AR can be acute, as observed in endocarditis and aortic dissection, or chronic, as seen in calcific aortic valve disease, connective tissue disorders, or bicuspid valve phenotypes. This review discusses the aetiopathology of these various AR manifestations (primary, secondary, acute and chronic AR), highlighting diagnostic challenges and implications for aortic valve replacement and transcatheter aortic valve implantation.