What is cardiac depolarization?

Cardiac depolarization refers to the process by which the heart's cardiac muscle cells undergo a change in electrical charge, leading to the initiation of a heartbeat. This occurs when sodium ions rush into the cells, causing the interior to become more positively charged. This electrical event triggers the contraction of heart muscle fibers, allowing the heart to pump blood effectively. Depolarization is a crucial part of the cardiac cycle, ensuring coordinated heart function.