Abstract: A cardiac assist system using a helical arrangement of contractile bands and a helically-twisting cardiac assist device are disclosed. One embodiment discloses a cardiac assist system comprising at least one contractile elastic band helically arrangement around a periphery of a patient's heart, where upon an actuation the band contracts helically, thereby squeezing the heart and assisting the pumping function of the heart. Another embodiment discloses a helically twisting cardiac-apex assist device comprising an open, inverted, substantially conical chamber with two rotatable ring portions of different diameters located at the base and apex of the chamber, with a plurality of substantially helical connecting elements positioned substantially flush with the chamber wall and connecting the two rotatable ring portions, whereby a relative twisting motion of the two rings causes a change in volume of the chamber thereby assisting the cardiac pumping function.