What Does "anterior Infarction Age Undetermined" In EKG Mean?

Hello. My EKG reveals that I have had an anterior infarction, when it happened is undetermined. My GP recommended I see a Cardiologist which I did last week. I have already done stress testing with IV dye and will receive more information this Wednesday. I am having chest discomfort which comes and goes, breathiness at times and pain in my back wing area. How concerned should I be?
Thank You,
Debra