Spontaneous Closure of Perimembranous Ventricular Septal Defects: A Janus-Faced Condition.

• Large perimembranous VSDs can occasionally close spontaneously by a septal aneurysm. • Complications of aneurysmatic VSD closure include RVOT obstruction. • The use of multimodal imaging allows accurate diagnosis of RVOT obstruction. • RVOT obstruction due to septal aneurysm is preferably treated by surgical excision. • Patients with aneurysmatic closure of perimembranous VSD need life-long observation.