I would suggest you ask your doc to refer you to a cardiologist. You can have a good calcium scan and still have beginning blockages. Or, as suggested above, electrical issues. I have a friend that his primary care doc gave him a stress ekg test… everything looked good… doc said your heart is good… 3 months later he had a heart attack… I just read that calcium scans don’t detect the beginning soft plaque build up that does not have much calcium in it yet… none of these tests are 100% accurate. Stay on it until you find some answers… Good Luck…