Heart valve disease (aortic valve disease): anatomy and pathology of the aortic valve

The gross features of the aortic valve apparatus, consisting of three semilunar leaflets, three interleaflet triangles, three commissures, and the aortic wall, are discussed both in terms of normal and pathological anatomy. The concept of aortic annulus and the relationship of the aortic valve with the coronary arteries, the membranous septum, and conduction system and the mitral valve are addressed. When dealing with pathology, the chapter focuses on the main distinctive features of aortic valve stenosis and aortic valve incompetence. Regarding the former, the abnormalities reside in the cusps, either two or three in number, with cusp thickening, and calcification with or without commissural fusion (thus distinguishing senile and chronic rheumatic valve disease); in the latter, the gross changes can affect either the cusps (infective endocarditis with tissue perforation/laceration and rheumatic valve disease with tissue retraction) or the aortic wall (ascending aorta aneurysm either inflammatory or degenerative). The distinctive gross abnormalities in the various conditions are illustrated.