In the 1940s, Claude Beck made an important observation during his work on heart fibrillation. He noticed that applying an electrical shock to a fibrillating heart resulted in the restoration of a normal heart rhythm. This critical finding led to the development of cardiac defibrillation, a technique that utilizes controlled electrical shocks to reset the heart’s electrical activity and bring it back into a regular rhythm. Since then, defibrillation has become a standard intervention for cardiac arrest and ventricular fibrillation, significantly improving survival rates. The discovery of cardiac defibrillation has revolutionized emergency cardiac care, providing a rapid and effective method to revive patients in life-threatening situations and restoring normal heart function.