The windsock syndrome: subpulmonic obstruction by membranous ventricular septal aneurysm in congenitally corrected transposition of great arteries.

Anomalies of the membranous portion of the interventricular septum include perimembranous ventricular septal defect and/or membranous septal aneurysm (MSA). In congenitally corrected transposition of the great arteries (L-TGA in sinus solitus), the combination of ventricular inversion and arterial transposition creates a unique anatomic substrate that fosters subpulmonic left ventricular outflow tract obstruction by an MSA. The combination of an L-TGA with subpulmonic obstruction by an MSA is referred to as the windsock syndrome. We report a case of windsock syndrome in a 25-year-old man which is to our knowledge the first three-dimensional echocardiographic description of this congenital entity.