A catheter sheath for an irrigation catheter comprises an elongate member having a proximal end and a distal end and defining a lumen extending from the proximal end to the distal end. At least one electrode is arranged on the elongate member. A plurality of elongate elements are contained in the elongate member, the elongate elements comprising at least one electrical conductor and at least one element of a non-conductive material arranged adjacent the at least one electrical conductor to form at least one non-conductive region associated with the elongate member. At least one passage extends through a wall of the elongate member to intersect the non-conductive region and to be in communication with the lumen of the elongate member. The at least one passage has an outlet opening in, or adjacent, the at least one electrode.