An implantable electrical lead of the type which has an insulative rigid electrode head carrying an advanceable helical electrode. The electrode head is mounted toan elongated insulative lead body which is less rigid than the electrode head and which carries an extensible conductor coupled to the helical electrode and an inextensible conductor coupled to the proximal end of the lead body. A second electrode is mounted to said lead body adjacent the electrode head and is coupled to the inextensible conductor by a conductive sleeve which is mechanically coupled to electrode head so that proximally directed traction forces applied to the lead body are applied by the inextensible conductor directly to the electrode head.