Subaortic Membrane-A Savior in Large Perimembranous Ventricular Septal Defect.

Ventricular septal defects (VSD) are the most common congenital cardiac defect. Patients with large VSDs present early due to an increase in the volume load on the left ventricle and pressure load on the right ventricle. Few of them present late even without surgical intervention, due to partial restriction of perimembranous (PM) VSD, either by the septal leaflet of the tricuspid valve or by aortic valve cusp prolapse into the VSD. The authors observed a novel structure (ie, subaortic membrane in this case) restricting the large PM VSD in a 15-year-old child.