Which wave represents atrial repolarization?

The correct understanding regarding atrial repolarization is that it is usually obscured by the QRS complex and is not typically seen on a standard electrocardiogram (EKG/ECG). This is due to the electrical events associated with ventricular depolarization, which generate the QRS complex and are much larger than those occurring during atrial repolarization. Consequently, the waves of atrial repolarization, if they occur, are masked by this larger electrical activity of the ventricles, making it difficult to discern them in a typical EKG reading.

In a normal EKG, the T wave represents ventricular repolarization rather than atrial repolarization, which further illustrates why atrial repolarization cannot be individually identified. There is also no clear association with a U wave for atrial repolarization in standard EKG analysis. Understanding these aspects of EKG interpretation is fundamental for recognizing the significance of the various waves and deflections present in the cardiac cycle.