Yes you are correct that many people feel differently during a stress test induced chemically. Even people with healthy hearts can feel a tightening in the chest and someone with disease may feel nothing at all. Maybe a key is how calm you stay during the inducing of the stress. I can imagine some people may let anxiety really kick in.
I'm glad you now know the problem, and I agree, stress tests are excellent for finding problems.
((((((((((((Aheart))))))))))) Lifting you up in prayer! Take care, Ally