My son has same symptoms, he has to stay away from caffeine, chocolate, cola, asthma meds, no amphedimines, no speed of any kind. And they also suggested beta blockers to make the stress less, so symptoms can subside. It is a real condition, most commonly not a fatal condition, it is worse with stress. Then you get it and you get more stressed, so never ending circle. You just have to tell yourself youre ok, and try to calm yourself. It is normal to stress when you think something is wrong with your heart. Normal, totally normal my son was told his is, premature ventricular contractions, or premature artial contractions. His beats would go so fast and then go back to normal, then it would feel like his heart was stopping. He misses beats and has long pauses along with fast beats. They did all the test he just has to stay away from any stimulants, and try to stay stress free--never did give him the beta blockers. Hope this helps you