Over the years, mechanical circulatoryassistance has progressively improved with the evolution of the clinical indications and the introduction of new devices. The management of situations of extreme emergency, cardiac arrest, acute myocardial infarction with cardiogenic shock, drug overdose, acute myocarditis, postoperative cardiac failure and post-transplantation right ventricular failure, may be undertaken with relatively simple systems such as the ECMO, in the catheter laboratory or at the bedside in the intensive care unit. These systems enable stabilisation of the circulatory problems in order to pass a difficult situation and then withdraw the assistance when myocardial function has been restored. When this is not possible and there is no contra-indication to cardiac transplantation, patients may benefit from more complex assistance devices as a bridge to transplantation. Many continuous flow pumps have been introduced recently. These small mono, left ventricular, assist devices provide improved patient comfort and suggest wider indications of long duration assist devices.