An infarct is necrosis (damaged) of heart cells usually due to insufficient blood flow to the area of concern. The condition occurs when there is obstruction to blood flow caused by plaque or a clot. Septal infarct refers to the heart wall that separates chambers.
Repolarization is an electrical impulse disturbance that indicates an arrhythmia (abnormal rhythm) problem that may be insignificant and infrequent. Repolarization is the heart cells recharging (during the filling phase) and prior to discharge (pumping phase).
If the EKG is not false positive (very possible), it would indicate a prior heart attack, or the heart cells are hibernating (medical term meaning the heart cells are not functioning due to ischemia {lack of blood flow} and can be revitalized to function normally if and when an ample suppy of blood/oxygen flows to the deficit area.