sounds like a panic attack to me. You're not listing some of the more worrisome symptoms of a myocardial infarction.
But please, do not rely on anonymous internet users for a diagnosis. You should be speaking with your doctor.
So they gave you the sht to make your heart race or did you walk it. Sounds like shot is it possible they gave you to much if you got the shot.
Good question, I assumed you were on a tread mill to get you pulse up to the target, well below 213 even for the young.
I have had several nuclear stress tests, all on the tread mill, and the only shot I got (best I can recall) was the shot of nuclear active fluid when I was up to the target HR, something like 135 for my age.
I have never had any ill affects from stress testing, other than the results which have shown a false positive - I did not in fact have any blockage as a heart catheter done later confirmed.
I had a treadmill test where they gave me an injection (in an iv) to increase my heart rate. Not sure if it was nuclear stress or not, but sounds like what I had. When the drug hit my system, it nearly knocked me down and I could not continue. Not sure if this will be useful to you, but thought I'd put it out there. I'm thinking if you'd had a heart attack, they would have treated you for it right then and there. Hard to imagine they would just let you go. You deserve answers -- ask your doctor.