Noun
an implanted electronic device that takes over the function of the natural cardiac pacemaker
Source: WordNetA pacemaker can be a natural pacemaker of the heart (the sinoatrial node) or it can be an electronic device that serves as an artificial pacemaker. Source: Internet
Very ill patients that are not responding to medical therapy may require implantation of an artificial pacemaker, and will be hospitalized prior to surgery in preparation of it. Source: Internet