An implantable heart assist system, includes a pumping chamber formed of a flexible material and being adapted to be placed in fluid connection with the aorta and a pump system comprising a first rigid member, a second rigid member spaced from the first rigid member so that at least a portion of the pumping chamber may be positioned between the first rigid member and the second rigid member, a drive system comprising a motor, an extending member comprising a threaded section operatively connecting the first rigid member and the second rigid member and a nut in operative connection with the threaded section. The motor is adapted to rotate either the extending member or the nut relative to the other to convert rotary motion of the motor to linear motion to cause the second rigid member to move toward the first rigid member or away from the first rigid member. The heart assist system further includes a controller or a control system in operative connection with the drive system and controlling the motor. Movement of the second rigid member toward the first rigid member results in compression of the pumping chamber, and movement of the second rigid member away from the first rigid member causes expansion of the pumping chamber.La présente invention concerne un système dassistance cardiaque implantable, qui comprend une chambre de pompage formée dun matériau flexible et étant adaptée pour être placée en raccordement fluidique avec laorte et un système de pompage comprenant un premier composant rigide, un deuxième composant rigide espacé du premier composant rigide de sorte quau moins une partie de la chambre de pompage puisse être positionnée entre le premier composant rigide et le deuxième composant rigide, un système dentraînement comprenant un moteur, un composant dextension comprenant une section filetée raccordant fonctionnellement le premier composant rigide et le deuxième composant rigide et un écrou en raccordement fonctionnel avec la section filetée. Le moteur e
