Fixed subaortic stenosis

The authors present a case of a 40-year-old female patient with fixed subaortic stenosis (SAS). This defect is classified into a group of diseases characterized by the presence of obstruction in the left ventricular outflow tract, which collectively includes stenotic lesions located in the region extending from the anatomical outflow tract of the left ventricle distally to the descending aorta. Obstructions are named according to their relationship to the aortic valve (subvalvular, valvular, and supravalvular) and their common denominator is an increase in the left ventricular afterload. Fixed subaortic stenosis may be either a focal stenotic lesion formed by a fibrous membrane, or a narrow muscular or fibromuscular tunnel diffusely tapering the outflow tract of the left ventricle. Individuals with SAS usually present with other congenital heart diseases such as a bicuspid aortic valve or perimembranous ventricular septal defect. Surgical resection of SAS is already indicated in asymptomatic individuals with severe SAS (peak gradient >50 mmHg). It is also advisable to consider surgery in some cases of less severe obstruction such as in those with coexistent moderate aortic regurgitation, ventricular septal defect, or in women planning pregnancy. In many cases, however, recurrence of SAS requires secondary surgical treatment. In the focal type of SAS, it is possible to indicate percutaneous balloon dilatation in some cases.