The combination of interventricular communication and left ventricular aneurysm is a rare situation. The interventricular communication is a lethal complication of myocardial infarction; it is a diagnostic and therapeutic emergency; it is observed in the anterior infarction and it is associated with a poor prognosis, the treatment involves surgical repair. The rupture of the basal portion of the septum is much rarer. Through the case of a patient who was hospitalized in our service, we illustrate the deadly complications of myocardial infarction while discussing its rare localization in the inferior left ventricular wall, its clinical, electrical and echocardiographic characteristics, as well as its rapidly fatal evolution without emergency care.