Patent ID: 7751904

Claim:
An electrode lead for implantation into a small heart vessel, or into a coronary sinus, comprising: an elongated outer insulating lead body ( 1 ), having a proximal end ( 2 ), a distal end ( 3 ) and at least one electrode pole ( 4 ) at the distal end ( 3 ); at least one electrical conductor unit ( 6 , 6 ′) for said at least one electrode pole ( 4 ), each of said at least one electrical conductor unit ( 6 , 6 ′) having a conductor core ( 7 ) and a separate insulating sheath ( 8 ) that surrounds said conductor core ( 7 ); a lumen ( 9 ) in said elongated outer insulating lead body ( 1 ), that is defined by a tubular envelope ( 10 ), configured to accommodate a guide wire ( 11 ); wherein the insulating sheath ( 8 ) that surrounds said at least one electrical conductor unit ( 6 , 6 ′) and the tubular envelope ( 10 ) of the lumen ( 9 ) are each in direct contact with each other and slidable relative to each other along their longitudinal direction (L) and fixed relative to each other in a vicinity of the distal end ( 3 ) of the elongated outer insulating lead body ( 1 ); wherein the at least one electrical conductor unit ( 6 , 6 ′) and the tubular envelope ( 10 ) of the lumen ( 9 ) are configured in a side-by-side relationship parallel to each other, wherein an entirety of the at least one electrical conductor unit ( 6 , 6 ′) and the tubular envelope ( 10 ) of the lumen ( 9 ) are encased by, the elongated outer insulating lead body ( 1 ); wherein said elongated outer insulating lead body ( 1 ) is configured to bend at said proximal end ( 2 ) in a first direction (Bu) which effects movement of the distal end of said elongated outer insulating lead body ( 1 ) in a second direction (Bd) that is opposite to said first direction when said at least one electrical conductor unit ( 6 , 6 ′) and said tubular envelope ( 10 ) move longitudinally with respect to one another wherein said insulating sheath ( 8 ) slides in direct contact with said tubular envelope ( 10 ); wherein the elongated outer insulating lead body ( 1 ) includes at least one flat outer surface region; and, wherein the at least one electrical conductor unit ( 6 , 6 ′) and the tubular envelope ( 10 ) of the lumen ( 9 ) are fixed relative to each other in the vicinity of the proximal end ( 2 ) of the elongated outer insulating lead body ( 1 ).