During the plateau and rapid repolarization phases (phases 2 and 3) of the action potential, the injury current will again flow from the more positive region (now the normal zone-the blue action potential) to the more negative region (now the ischemic zone-the red action potential). Thus, its direction will be from the normal zone toward the ischemic zone, i.e. opposite in direction to the current flowing during phase 4. This will cause elevation in the ST segment and T wave in electrograms recorded by electrodes overlying the ischemic region.