Classical the etiology and pathology of aortic insufficiency have been altered in the last 10 years. The possibility of surgical amelioration provided the stimulus for a more detailed and exacting clinical study of aortic regurgitation and investigation of the dynamic effects produced by mechanical alterations in valve closure. These have led to a more adequate understanding of the natural history of the disease as seen in modern times and to the recognition of many more etiologic factors than had previously been known.
While rheumatic fever is now the most common cause of aortic insufficiency, many of the other causes are sufficiently common to be of major importance. These include congenital malformations, trauma (blunt or penetrating), acute endocarditis, subacute endocarditis, dissecting aneurysms, ruptured aneurysms of the sinus of Valsalva, aneurysms of the ascending arch, and dissecting aneurysms. Syphilis, which in the past was a major etiologic agent, has been much less