MODEL RELEASED. Pacemaker insertion scars on the chest of an 87-year-old man. The old pacemaker was removed from the left side of his chest and a new one inserted on the right side of his chest. A pacemaker uses electrodes to provide electrical impulses to regulate the beating of the heart. The pacemaker is inserted under the skin at a suitable point on the body. Modern pacemakers are wireless, transmitting signals to the electrodes placed in the heart. Photographed 10 days after the operation.