This problem is a heart electrical issue more than a rhythm one, but I'm guessing some of you might know more about this issue, too, and these changes weren't mentioned in the initial report.
I had a 24-hour holter, and the report said normal, but when I requested the actual data, I found the ischemic narrative shows significant ST changes, both elevations and depressions, and for longer durations than 1 minute. The ST elevations occurred while I was exercising.