I had a bad bout of it last night. I had an EKG, x-ray, and blood test last month, plus my doctor and the testing doctors checking my pressure and heart with stethoscope, and they said everything was fine. It's still scary, and makes me feel ill and anxious. I told my doctor, and the other one about it, but they don't really seem to react as though it's a big deal. Next week when I go to my GP for a follow up I'm going to ask for a bit more in depth answer as to why it happens and if it's a serious risk. I've had this during periods of anxiety for 15 years, so in a way I know it's not the end of me, not too likely anyway, but I would like it to end someday.