Electrode assembly with a feed line presenting three channels and with a positioning and fixation device

The electrode arrangement has two large surfaces that are arranged with lead wires (10,16). A pacing electrode with pole is located between electrodes arranged over large surface. A positioning fixation device is provided with guide channel (5) and stylet (6). A supply line (4) having three hollow channels is fixed closure to opening in chest or abdomen, and the lead wires are introduced via proximal end (11) of hollow channels for performing cardiac surgery.