A single-pass endocardial lead electrode adapted for implantation on or about the heart and for connection to a system for monitoring or stimulating cardiac activity including a lead body with a circumferential outer surface. The lead includes a first distal end electrode which has a first electrical conducting surface which is for positioning within the ventricle of the heart. The lead body also has a second electrode which has a second electrical conducting surface adapted for positioning within the atrium of the heart. Both of the first and the second electrodes are adapted for positioning and fixation to the wall. An active fixation element is used as part of the second electrode. The lead body also includes a curved portion which facilitates the positioning and fixing of the second electrode. In another embodiment, the main lead body includes a recess into which an atrial lead body and the active fixation element attached to one end can travel from a recessed position to a position for fixation to the wall of the heart. The active fixation element which can also be moved by turning the terminal pin.