Abnormal left ventricular outflow tract morphology Subaortic ventricular septal bulge 2018-07-07T23:58:07Z A localized hypertrophy of the subaortic segment of the ventricular septum has been frequently described in elderly persons, and variously termed subaortic ventricular septal bulge (VSB), sigmoid-shaped septum, localized or discrete upper septal hypertrophy. Subaortic ventricular septal bulge has been considered mainly as an incidental finding associated with older age and hypertension, although some authors have suggested that it may be part of the spectrum of hypertrophic cardiomyopathy, may determine some degree of left ventricular (LV) obstruction, which in turn may potentially cause symptoms such as syncope and dyspnea on effort.