What does a "repolarization wave" signify?

A repolarization wave signifies the recovery phase of cardiac muscle cells after they have been depolarized. During depolarization, the heart muscle cells (myocytes) contract as sodium ions flow into the cells, leading to a change in the cell's electrical charge. Once the contraction occurs, repolarization follows to restore the electrical state of the cells to their resting potential. This process is crucial for the proper functioning of the heart, as it allows the cells to be ready for the next electrical impulse and subsequent contraction.

Understanding repolarization is fundamental to recognizing the cardiac cycle, as it reflects the essential stages of the hearts' electrical activity and the corresponding mechanical actions. The heart relies on effective repolarization to ensure that contractions are followed by adequate relaxation, which is necessary for optimal blood circulation.