Interventricular membranous septal aneurysm is seen on multidetector computed tomography in postoperative child

Ruptured interventricular septal aneurysms are rare. We present a case of an interventricular membranous septal aneurysm in a 7-year-old boy who presented with features of congestive heart failure, 2 years after undergoing a patch closure of perimembranous ventricular septal defect and tricuspid valve repair. Material and methods and results: Transthoracic echocardiography suggested the presence of an aneurysm that has ruptured into the right ventricle (RV), however, the precise origin of the aneurysm could not be identified on echocardiography. Subsequently, a computed tomography (CT) angiography was done which revealed that the aneurysm was originating from the membranous interventricular septum with evidence of rupture into the RV inflow.

Due to its close proximity to the aortic annulus, an aneurysm of the membranous interventricular septum may be confused with a sinus of Valsalva aneurysm, especially if the former is associated with aortic regurgitation.

This case highlights the importance of CT in the precise differentiation of these two abnormalities.