realized in has material basis at all times has occurrent part disturbed anterograd blood flow through aortic valve during left ventricular systole aortic valve disorder aortic valve improper opening during left ventricular systole aortic valve stenosis aortic valve stenosis UMLS_CUI:C0003507 A disease in which some disorder of the aortic valve leads prevents it from opening properly during left ventricular systole, occasioning disturbance in the anterograd blood flow through the valve. AS Aortic valve stenosis is a aortic valve disease caused by the incomplete opening of the aortic valve. The aortic valve controls the direction of blood flow from the left ventricle to the aorta. When in good working order, the aortic valve does not impede the flow of blood between these two spaces. Under some circumstances, the aortic valve becomes narrower than normal, impeding the flow of blood. This is known as aortic valve stenosis, or aortic stenosis, often abbreviated AS. SNOMEDCT_2010_1_31:60573004 Aortic stenosis MSH:D001024 NCI:C50462 Aortic valve stenosis (disorder) DOID:1712 disease_ontology SNOMEDCT_2010_1_31:390722003 disease disease course