Aortic valve closure during early or middle systole.
Early systolic closure of the aortic valve (ESC) is a non-specific echocardiographic finding which occurs in a wide range of conditions such as hypertrophic (obstructive) cardiomyopathy (HCM), fixed subaortic stenosis, ventricular septal defect with and without Eisenmenger reaction, mitral regurgitation, aortic root dissection, double outlet right ventricle, ruptured right sinus of valsalva aneurysms, diverticulum of the left ventricle, congestive cardiomyopathy and even in normals. When ESC occurs in the presence of clinical features of left ventricular outflow tract obstruction it raises the strong possibility of a subvalvular lesion but its absence does not exclude any of the form of sub-valvular stenosis. When ESC occurs in hypertrophic cardiomyopathy it is likely that an intra-ventricular pressure gradient is presented, but gradients can be found in the absence of ESC and the degree of ESC does not correlate with the size of any such gradient. ESC is not always present in fixed sub-aortic stenosis, neither the presence nor the degree of ESC correlates with the pressure gradient. It does not permit differentiation between the three types of fixed subaortic stenosis as it may occur in any of them. ESC is almost certainly caused by alteration in the pattern of blood flow in the aortic root, although the factors which influence the patterns of flow are imperfectly understood and merit further study.
D001021:Aortic Valve / Q000503:physiopathology*; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology; D004452:Echocardiography / Q000379:methods; D006345:Heart Septal Defects, Ventricular / Q000503:physiopathology; D006801:Humans; D010701:Phonocardiography; D013599:Systole