The effects of repolarization on the EKG are similar to those of depolarization, except that the charges are reversed. A wave of repolarization moving toward a positive electrode inscribes a negative deflection on the EKG. A wave of repolarization moving away from a positive electrode produces a positive deflection on the EKG. A perpendicular wave produces a biphasic wave; however, the negative deflection of the biphasic wave now precedes the positive deflection.
The EKG finally returns to baseline once again when depolarization is complete.We can easily apply these concepts to the entire heart. Electrodes placed on the surface of the body will record waves of depolarization and repolarization as they sweep through the heart.
If a wave of depolarization passing through the heart is moving toward a surface electrode, that electrode will record a positive deflection (electrode A). If the wave of depolarization is moving away from the electrode, the electrode will record a negative deflection (electrode B). If the wave of depolarization is moving perpendicularly to the electrode, the electrode will record a biphasic wave (electrode C). The effects of repolarization are precisely the opposite of those of depolarization, as you would expect.