The heart beats with perfect rhythm — thanks to its own electrical conduction system. It starts at the sinoatrial (SA) node — the heart’s natural pacemaker — which generates impulses that spread through the atria. The signal slows at the atrioventricular (AV) node, then travels through the bundle of His, down the bundle branches, and into the Purkinje fibers, triggering coordinated ventricular contraction. This animation highlights the heart’s conduction system in motion. Based on SciePro’s 3D a