A heart assist system includes an axial-flow blood pump capable of being implanted in the descending thoracic aorta; a pressure-feedback controller connected to the pump, for controlling the pump, the controller capable of being implanted in the body; and a rechargeable battery pack connected to the pump and to the controller, for providing power to the pump, the battery pack capable of being implanted in the body.A method for assisting a failing heart comprises the steps of a) in response to when a measured dP/dT signal increases during systole, signaling an implanted aortic blood pump to go into a systolic mode and pump blood at a first flow rate; and b) in response to when the dP/dT signal peaks in the negative region, signaling the pump to go into a diastolic mode and pump blood at a second flow rate.