A catheter assembly (10) includes a handle body (12) having a proximal end (14) and a distal end. An introducer carrier (18) is displaceably arranged relative to the handle body (12). An electrode sheath component is arranged at a distal end of the handle body (12), the electrode sheath component comprising at least one pair of limbs interconnected by a bridging portion, at least the bridging portion carrying at least one electrode. An elongate shape forming component (40) is received in a lumen of the electrode sheath component, the shape forming component (40) having at least one predetermined shape formed along its length. An introducer component (22) is carried on the introducer carrier (18) of the handle body (12). The electrode sheath component is received within the introducer component (22) prior to use with at least the bridging portion of the electrode sheath component being extended out of a distal end of the introducer component (22) to be exposed for use. The arrangement is such that movement between at least two of the components relative to each other results in a change of shape being imparted to the exposed bridging portion of the electrode sheath component.