Despite a marked reduction in mortality after myocardial infarction during the last decades thanks to heart monitoring and early reperfusion, there remains a significant rate of in-hospital mortality. This is a consequence of refractory ventricular dysfunction in most cases, or mechanical complications of myocardial infarction in the remaining cases. Mechanical complications include septal rupture with ventricular septal defect, tamponnade following rupture of the left ventricular free wall, and acute mitral regurgitation due to papillary muscle infarction and rupture. Although these complications are rare, their prognosis is very poor. An early detection of clinical signs of mechanical complications is crucial to urgently precise the diagnosis by echocardiography and subsequently plan the most appropriate medico-surgical management.