Abstract: A guide tube means for assisting in the fixation of an electrode to the heart of a patient, with the guide tube means being adapted for releasable retention of the electrode and its associated leads, the guide tube means including a lead-retaining sleeve along with a rod means for controllably dislodging the leads from the sleeve. The rod means includes means for releasably retaining the insulative backing or pad for the electrode, and is further provided with a radially extending ear for dislodging the electrode lead from the sleeve upon withdrawal of the rod means from the sleeve, thereby providing for the formation of a slack loop or segment adjacent the site of the electrode, the slack portion permitting relative motion to occur between the end of the guide tube and the electrode as fixed in position.