What is repolarization in terms of heart function?

Repolarization refers to the phase in the cardiac cycle when the heart's electrical system resets after depolarization, which is the phase that initiates muscle contraction. During repolarization, the myocardial cells return to their resting electrical state following the contraction. This process is critical for preparing the heart for the next heartbeat, ensuring that each contraction is followed by a recovery period, maintaining the heart's rhythm and function.

In the context of the heart's electrical activity, repolarization is primarily associated with the recovery of the cardiac action potential. Specifically, it is during this phase that potassium ions exit the cardiac cells, restoring the negative charge inside the cells after depolarization has occurred. This resetting is essential for the heart to maintain coordinated contractions and prevent arrhythmias.

Understanding this concept is key to grasp how the heart rhythmically pumps blood and maintains effective circulation.