Pacemakers are battery operated electronic devices which give an electric impulse to the heart. They are used to treat an irregularly beating heart, slow heart, heart block etc. The pacemaker consists of a pulse generator (with a lithium battery and an electronic circuit) and an electric lead. The electric lead is attached to the heart and the pulse generator is logded under the skin in the upper part of the chest. The procedure is done under local anaesthesia. Pacemakers can increase the life span of the patient.