A single-pass pacing lead capable of sensing and pacing both the atria and the ventricles is described. In some examples, the single-pass pacing lead is connected to a DDD pacemaker. In some examples, the single-pass pacing lead comprises four electrodes. In some examples, the lead includes three electrodes configured to be positioned in or near an atrium, e.g., the right atrium, and one electrode configured to be positioned in or near a ventricle, e.g., the left ventricle, when the lead is implanted. In other examples, the lead includes two electrodes configured to be positioned in each of the atrium and ventricle when the lead is implanted. In some examples, one of the electrodes, which is configured to be positioned proximate the coronary sinus ostium when the lead is implanted, comprises a helical element for fixation of the lead to tissue.
