Decompensated heart failure, either acute (cardiogenic shock) or chronic (terminal heart failure) may become refractory to conventional therapy, then requiring mechanical assistance of the failing heart to improve hemodynamics. In the acute setting, aortic balloon counterpulsation is used as first line therapy. In case of failure, other techniques include the extracorporal membrane oxygenator or a percutaneous left ventricular assist device, such as the TandemHeart or the Impella. In chronic heart failure, long-term left ventricular assist devices can be surgically implanted. The continuous flow devices give here the best results. The aim of the present review article is to present with some details the various methods of mechanical left ventricle assistance to which the intensivist may be confronted in his daily practice.