A pacemaker is an electronic device that senses electrical activity of the heart/heart rhythm. It can also send electrical signals to the heart muscle to make it beat regularly. One of the common reasons for pacemaker insertion is if the heart is beating too slow. Pacemaker is usually inserted in the left upper or right upper chest below the skin. It consists of a metal case and electrical wires (leads) that are connected to the heart muscle. There are different types of pacemakers and cardiologists usually decide which type of pacemaker is needed depending on the patient’s condition.