Aneurysm of the membranous septum. A potential cause of sudden death

Aneurysms of the membranous septum are extremely rare malformations that are usually asymptomatic. However, they have the potential for varied complications including sudden cardiac death. Reported here is a case of sudden death in a 25-year-old woman. A medico-legal autopsy revealed a large aneurysm of the membranous septum. It is speculated that the infiltration of fibrous tissue from the aneurysm into the atrioventricular conduction axis may have led to the observed mortality.