Discrete subaortic stenosis (DSS) in childhood: a congenital or acquired disease? Follow-up in 65 patients.

Discrete subaortic stenosis (DSS) is a frequent malformation easily diagnosed by echocardiography; surgical resection of the membrane is the most suitable treatment. However, some evolutive aspects of the lesion remain unexplained (the presence of aortic dysfunction, associated malformations, etc.). With a view to analyse these aspects, we have studied 65 patients with DSS and divided them into two groups: Group I, 37 patients without surgery, and Group II, 28 patients treated by resection of the membrane. During follow-up we observed: (a) development of aortic regurgitation in operated and non-operated cases; (b) frequent association of DSS with closed or closing ventricular septal defect; (c) the absence of DSS in neonates and (d) the progressive growth of the membrane. These aspects give this malformation an evolutive character that requires observation and management even after resection of the DSS.