The electrode wire (10) has a distal electrode carrier body (20) which carries at least one electrode (24), and which is connected via a wire bridge (22) to a distal end of an elongate electrode wire section (12). The wire bridge is preformed so that it is not extended when slack, and is elastically extensible. The elongate electrode wire section includes a lumen, which adjoins a distal opening through which a guide wire (10) can emerge. An independent claim is included for an implantation tool.
