A system for artificial stimulation of the heart of a subject comprises a controller comprising a receiver for receiving signal data, a processor for processing received signal data, and a transmitter for transmitting signal data； a sensing stent for location in the proximal coronary sinus of the subject and comprising a sensing electrode assembly for sensing atrial and/or ventricular signals from the heart of the subject and a transmitter for transmitting signal data to the receiver； a stimulation stent for location in a vein of the subject distal of the sensing stent and comprising a receiver for receiving signal data from the transmitter and an electrode assembly for providing a stimulating electrical signal to the heart in response to the data received； and a defibrillator assembly for providing stimulation to the heart sufficient to defibrillate the heart in response to a signal received from the controller assembly.
