A body implantable lead comprises a lead body including a conductive polymer electrode disposed along a distal end portion of the lead body for performing one or more of the functions consisting of pacing, sensing, cardioversion and defibrillation. An electrical conductor, preferably in the form of a multistrand cable conductor, couples the conductive polymer electrode with a proximal end of the lead body. The conductive polymer electrode encapsulates the conductor and is in electrical contact therewith along the length, and preferably along substantially the entire length, of the conductive polymer electrode. The lead body may comprise a multilumen polymer housing, the conductor being contained within one of the lumens of the housing. The conductive polymer electrode may be disposed within a window formed in the lead body. Alternatively, the conductive polymer electrode may comprise multiple electrode sections within a corresponding number of windows formed in the lead body and spaced apart along the length thereof. Further, the window and the conductive polymer electrode disposed therein may extend helically about the lead body. Because of its flexibility and because it can have a small diameter, the lead of the invention is particularly advantageous for implantation in the small, tortuous vessels of the coronary sinus region of the heart for left side stimulation and/or sensing. Methods of fabricating lead bodies incorporating conductive polymer electrodes are also disclosed.