However, comparing the trace elements injected at rest at during the high heart rate period of the stress test
may show that there is a blockage
of an artery and during exercise, your heart is not getting enough blood in parts of it. The cath will give the doctor specific answers.
I'd try to stress about it, but the period of time after a stress test and before a cath is always a worrisome time, I've gone through that a number of times.