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

Background: 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. Discussion: 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. Conclusion: This case highlights the importance of CT in the precise differentiation of these two abnormalities.