Which wave in an ECG indicates ventricular repolarization?

The T wave in an ECG signifies ventricular repolarization, a crucial phase in the cardiac cycle. During this phase, following the depolarization represented by the QRS complex, the ventricles are recovering and returning to their resting state after contracting. The shape and duration of the T wave can provide insights into the health of the heart's electrical activity and can indicate issues such as ischemia or electrolyte disturbances.

The P wave is associated with atrial depolarization, initiating the cardiac cycle with the contraction of the atria. The QRS complex represents the rapid depolarization of the ventricles, leading to their contraction. The U wave is not as commonly observed but is thought to represent the repolarization of the papillary muscles or the end of ventricular repolarization, and it generally follows the T wave. Thus, the T wave is the clear marker indicating the completion of the electrical recovery of the ventricles.