What physiological change occurs during the T wave of an ECG?

During the T wave of an ECG, the physiological change that occurs is ventricular repolarization. This represents the process by which the ventricles of the heart recover from the depolarization that occurred during the preceding QRS complex, where ventricular contraction happens. The T wave visually reflects this repolarization on the ECG, and it is crucial for the heart's electrical cycle, as it prepares the ventricles to be ready for the next cardiac cycle.

Understanding that this phase is about the recovery of the ventricles helps clarify its importance in maintaining proper heart rhythm and function. An abnormal T wave can indicate issues such as electrolyte imbalances or other cardiac pathologies, making recognition of this wave critical for effective cardiac monitoring.