What EKG representation corresponds to Bundle of His and Purkinje fibers repolarization?

The correct choice is the U Wave, which is believed to represent the repolarization of the Bundle of His and Purkinje fibers. The U Wave is less commonly seen on an EKG but can appear in certain conditions. It comes after the T Wave and can provide insights into the repolarization process, particularly that of specialized conduction pathways in the heart.

The QRS Wave represents ventricular depolarization, which is the electrical activity associated with the contraction of the ventricles. The T Wave, on the other hand, represents the repolarization of the ventricles after contraction. The P Wave reflects the depolarization of the atria, occurring even before the QRS complex. Understanding the distinct roles of these waves is essential for interpreting EKGs and recognizing the activity of various components of the heart's conduction system.