Beshlyaga V. Discrete subaortic stenosis: diagnostics, indications to surgical treatment and estimation of its results on the basis of a complex echocardiography.

The dissertation is dedicated to the diagnostics and to the study of anatomic variants of a discrete subaortic stenosis (SubAS), to the research of hemodynamic disturbances and to determination of indications to operative treatment, to its differential diagnostics with valvular and supravalvular aortic stenosis and with hypertrophic obstructive cardiomyopathy on the basis of the method of a complex echocardiography (ECHO). On the basis of examination of 219 patients with isolated SubAS, the modern method of diagnostics of the SubAS and estimation of the degree of hemodynamic disturbances were developed and introduced into practice. A gradient of systolic pressure (GSP) between LV and aorta, measured from ECHO is one of the basic criteria for the estimation of a degree of the SubAS, for determination of indications to surgical treatment. The most informative parameters highly correlating with GSP, are parameters of a LV hypertrophy (indexed LV mass - ІММ), relation of LV mass to end-diastolic volume (MM/EDV) and relation of end-diastolic dimension to LV wall thickness in diastole (EDD/h), which are recommended as additional criteria for estimation of a degree of the SubAS. By results of the research the specified indications to operative treatment were elaborated.