A lead wire associated with a pacemaker, implantable cardiac defibrillator or other cardiac electric signal source is provided with a protector tube overlying at least a portion of the lead wire. In one embodiment, this protector tube is provided as a sheath tube portion of a sheath assembly along with a valve body. The valve body of the sheath assembly is fracturable and removable away from the sheath tube, leaving the sheath tube upon the lead wire as a protector tube. In other embodiments, a separate protector tube is provided and fed over the lead wire and through a sheath assembly until placed where desired. A grommet and/or plug can be provided at a proximal end of the protector tube for anchoring of the protector tube in a desired location and for plugging the protector tube, while also accommodating the lead wire passing therethrough.