The Aortic Valve and Aorta

Abstract

The aortic valve (AV) is a semi lunar valve and, like the mitral valve, lies close to the esophagus allowing excellent visualization with TEE. The valve itself consists of 3 cusps (right, left, and noncoronary) attached to a fibrous annulus, and unlike the atrio-ventricular valves, it does not have any anchoring supports (e.g., chordae tendinae) to maintain the integrity. The integrity is dependant mainly on the annulus geometry and the ratio of annulus: cusp area. The annulus geometry is affected by the inter-ventricular septum and proximal aortic root, and pathologies of either can alter the annular shape and cause incompetence of the valve. There is about 30% overlap of each cusp with its neighbor, and the total cusp area must exceed the cross sectional area of the annulus in order to maintain competency with a normal ratio being greater than 1.6:1; any pathology that decreases cusp area or increases annular area will therefore lead to incompetence and regurgitation through the valve.