I Had An EKG Done For An Upcoming Gallbladder Surgery.

I had an EKG done for an upcoming gallbladder surgery. Just got word from my Dr. that my EKG came back abnormal with an "anterior infarct". I am to see a cardiologist on Friday, but would like to know a little more before then. Is it possible to have a heart attack and not know it? Granted I am an obese 38 year old woman, but have no history of high blood pressure, diabetes, do not smoke, and cholesterol is on high end of normal. How concerned should I be about this EKG result?