Thallium tests show black spots on the areas of the heart that are not getting enough oxygen, so it is a good test for anyone who is having unexplained chest pain. If your doctor says to have one, don't hesitate.
My husband waited until it was too late. He had a heart attack, but had a thallium scan after his surgery to make sure the surgery worked. I think if he'd had it before, he wouldn't have had the heart attack.