A valve prosthesis system is provided, which includes a prosthetic aortic valve and a non-implantable unit. The prosthetic aortic valve which includes a plurality of prosthetic leaflets； a frame； a cathode and an anode, which are mechanically coupled to the frame； and a prosthetic-valve coil, which is in non-wireless electrical communication with the cathode and the anode. The non-implantable unit includes an energy-transmission coil； and non-implantable control circuitry, which is configured to drive the cathode and the anode to apply a pacing signal and to set parameters of the pacing signal, by wirelessly transferring energy from the energy-transmission coil to the prosthetic-valve coil by inductive coupling. Other embodiments are also described.
