The word ischemia means "decreased blood/oxygen supply".
Ecg, although regularly used to detect blockages in the coronary arteries, is not the best tool available. If the interpretation that you read on your ecg is made by the ecg machine itself then it is not very reliable unless it was confirmed by a physician.
You have to go back to your doctor (or the doctor who did the annual physical exam) and ask him about the ecg results.