Disclosed is an implantable two-chamber system for supporting the left ventricle of the heart. Each of the two pumping chambers (1, 1') of said two-chamber system has the shape of a ventricular bag comprising an inlet (11) that is embodied at one end at an acute angle (α) to an outlet (12), directly next to said outlet (12). Furthermore, a pressure plate (2) is rotatably mounted externally in two arms (5) which are movably retained on the output shaft (9) of a drive unit (15) such that the center of motion (8) of the arms (5), which lies on the output shaft (9), is located on the side of the pumping chambers (1, 1') facing away from adapters (4, 4'), and thus outside said pumping chambers (1, 1'). The angle between the inlet (11) and the outlet (12) of each pumping chamber ranges from 30° to 60°. The maximum width in the inlet and outlet zone of each of the pumping chambers (1, 1') amounts to about 65 to 72 percent of the length of the respective pumping chamber. In addition, each of the ventricular pumping chambers (1, 1') is provided with a bulge (13) adjacent to the inlet (11) in order to reduce the resistance to fluid flow, said bulge (13) having a length ranging from 10 to 15 percent of the length of the pumping chamber. The diameter of the inlet (11) and the outlet (12) amounts to about one third of the length of the pumping chamber.