Pacemaker is used to help your heart beat more regularly. A pacemaker consists of four parts, the pulse generator, electrodes, leads and battery. Pulse generator - A battery and the electric circuitry in the small metal container control the rate of electric pulses transmitted to your heart. Leads and electrodes - Each chamber of your heart has one to three flexible insulated wires and offers the electrical pulses to adjust your heart rates. Electrodes at the ends of the leads, to help deliver the signals Pacemakers only work when necessary. If the heartbeat is too slow, the pacemaker will send electrical signals to your heart to correct the beat. The arrhythmia team uses pacemakers to sense and correct abnormal heart rhythms. Most commonly there are two types of abnormalities: 1) Bradycardia: If a patient has bradycardia, their heart rate is slower than 60 times a minute. There are two types of bradycardia, including: AV block – Not all heartbeats can travel from the top chamber up to the bottom of the heart in this type of bradycardia. For an AV block, there are various severity levels. Sinus node dysfunction – This type of bradycardia occurs when a sinus atrial node (SA) electric signal is slowed or completely gone and the SA node does not generate enough beats. SA nodes is normal pacemaker of heart. 2) Heart block: electric signals that slow or disrupt when moving from the upper to the lower heart chambers. In addition, newer pacemakers have body motion or respiratory sensors which signal that cardiac speeds are increased during practice, when required.