Heart Attack Support Group
Heart attack is a serious, sudden heart condition usually characterized by varying degrees of chest pain or discomfort, weakness, sweating, nausea, vomiting, and arrhythmias, sometimes causing loss of consciousness. It occurs when the blood supply to a part of the heart is interrupted, causing death and scarring of the local heart tissue.
What you are describing sounds like a lot of heart issues, but also nothing. I know that's not very helpful but it is reality.
Self diagnosis is part of the problem you are facing. So many people today use the internet to self diagnose that doctors and frankly insurance cannot keep up. Most prove to be shall we say from other than medical causes? So that further exacerbates the issue when someone is trying to get to the root of a problem.
You should understand that no single test can identify all the possible issues that can happen with the heart, so you have to have patience and be persistent with your Cardiologist.
Don't worry about the possibility you won't finish the stress test, that at least will tell the doctor a lot. As for the possibility of open heart surgery you are leaping way ahead and making assumptions that could and likely are way off base. Stop driving yourself nuts and just focus on one day at a time.
Good luck on the test.