An implantable two-chamber system is for supporting the left ventricle of the heart. Each of the two pumping chambers (1, 1′) of the two-chamber system is ventricular shaped including an inlet (11) and an outlet (12). 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 chamber (1, 1′) facing away from adapters (4, 4′), and thus outside the pumping chambers (1, 1′). Each of the ventricular pumping chambers (1, 1′) is provided with a bulge (13) in order to reduce the resistance to fluid flow, this bulge (13) having a length ranging from 10 to 15 percent of the length of the pumping chamber.
