[Giant aneurysm of the interventricular septum. Value of imaging techniques]

A pseudosubaortic left ventricular aneurysm was discovered in a 32 year old African presenting with pyrexia after a long history of chest pains and dyspnea. Echographic and radiological techniques showed a large pulsatile mediastinal mass and the patient was referred for aneurysmorrhaphy. The actiology of this pseudo-aneurysm is discussed with reference to data in the literature. Infection is the first cause to be excluded in view of the pyrexia truncated by "blind" anti-inflammatory and antibiotic therapy. The hypothesis of an interventricular septal abscess secondary to septicaemia with secondary rupture into the pericardium is discussed. Precessive endocarditis with an aseptic abscess is unlikely because of the minimal aortic valve lesions, the absence of vegetations and the very long clinical evolution. Finally, idiopathic pseudo-aneurysms in sub-Saharian Africans, due to a congenital defect of the fibrous aortico-mitral and subannular zones must be considered. The risk of complications of these pseudo-aneurysms justifies surgical intervention on the accurate anatomical description of the lesions provide by transthoracic and transoesophageal echocardiography and magnetic resonance imaging.