Implantation of Permanent Pacemaker (PPM) A pacemaker is a small electronic device implanted in the chest, just beneath the skin below the collar bone. It functions to reduce the symptoms caused by abnormally slow heart rhythm. The pacemaker is capable of monitoring the heart rhythm. When the heart is beating normally, the device remains inactive. If the heart beats too slowly, the pacemaker delivers a small electrical current to the heart to stimulate the heart to beat at a normal rate. Modern pacemakers are unobtrusive and do not affect daily activities.