The AV node, or atrioventricular node, is a small cluster of cells located in the heart. It plays a crucial role in the electrical conduction system by receiving signals from the sinoatrial (SA) node, which initiates the heartbeat. The AV node acts as a gatekeeper, slowing down the electrical impulses before they pass to the ventricles, allowing the atria to contract and fill the ventricles with blood. This delay is essential for maintaining a coordinated heartbeat. If the AV node is damaged or malfunctioning, it can lead to various heart rhythm disorders, affecting the heart's ability to pump blood effectively.