Which event occurs during ventricular repolarization?

Ventricular repolarization is primarily represented by the T wave on an electrocardiogram (ECG). During this phase of the cardiac cycle, the ventricles recover from the depolarization that occurred during contraction (systole). As the myocardial cells in the ventricles return to their resting state, an outward movement of potassium ions occurs, leading to a decrease in the electrical activity of the ventricles. The T wave signifies this repolarization process, highlighting the time when the ventricles are resetting their electrical state in preparation for the next heartbeat.

The P wave, on the other hand, represents atrial depolarization, which occurs before the ventricles contract. The QRS complex corresponds to ventricular depolarization, indicating the moment the ventricles contract. Atrial systole refers to the contraction of the atria, which contributes to filling the ventricles but does not pertain to the repolarization process of the ventricles. Understanding these specific phases is crucial for interpreting cardiac rhythms and diagnosing potential cardiac issues effectively.