You mention a heart doctor (cardiologist?) and a stress test. My understanding of a stress test, I've had several, most nuclear stress tests, is to check on how well the blood is getting to heart muscles. Given you got good results on the stress test (here stress refers to physical stress on the body/heart, not mental stress) it is unlikely that you have any blockage - that's good.
You didn't mention EKG, but you did have a holter monitor.