Floppy aortic valve presenting as sudden death.

A previously healthy 34-year-old Dutch immigrant to Australia died unexpectedly in his sleep. At autopsy the only significant finding was a floppy aortic valve (FAV). Histologic, histochemical and electron microscopic studies corroborated the macroscopic diagnosis. Previously described associations of the FAV include the floppy mitral valve, Marfan's syndrome, aortic root dilatation and aortic cystic medial necrosis. None of these features were found in the present case which is the first recorded example of isolated FAV presenting as sudden death. The mechanism of death is obscure, and while it is presumed to be dysrhythmic, a detailed histological examination of the cardiac conducting system revealed no anatomic abnormality.