go to the ER. I just read this to my brother in law who had bypass surgery a few weeks ago and he had the same complaints. He said his tests (stress test, echo, nuclear) came back fine. he had an angioplasty which showed 90 percent blockage. he had a five way bypass and doc said lucky to be alive.
he WAS also a smoker, but not anymore.
it doesn't mean you have anything, but you need to rule out anything serious.