Visual captures the fascinating yet concerning difference between a normal heart rhythm and atrial fibrillation (AFib) — one of the most common cardiac arrhythmias. On the left, the normal heart beats in a calm, coordinated rhythm. Electrical impulses begin in the sinus node, the heart’s natural pacemaker, located in the right atrium. From there, the signals flow smoothly through the atrioventricular (AV) node and into the ventricles. This precise conduction system ensures the heart contracts in