<s>[INST] Every once in a while I will get uncontrollably shaky and my heart rate is already naturally over 100 but it beats faster at certain moments. Sometimes there will be moments where it hurts to breath and there is a stabbing pain on the side where my heart is. I have gone to a doctor but they say it is just a panic attack. My problem with them summing it up to being that is that these symptoms will only occur randomly. I could be feeling great with no worries, I could be completely stressed out. It never has a connection. I am currently at work and I can t seem to calm down, I keep shaking and my heart is beating a little bit faster. What is wrong? Doctors keep summing it up to anxiety or panic attacks. Is that true? [/INST] Hi Anxiety is likely but not the only cause.  There could be several reasons - it sometimes happens normally also!  Anxiety may not be the case with you - random and no relation, as you say.  It may be Mitral Valve Prolapse, anomalous pathways and so on.  Proper treatment needs proper diagnosis. First thing to do will be to see a cardiologist and get examined - especially during one such episode.  In this situation, we start with routine ECG, ECHOcardiogram, blood tests (cell count, sugar, thyroid).  If there is no clue, we go further - 24 to 48 hour ambulatory ECG monitoring (Holder).  Your doctor will decide on the need for medications - beta blockers for example can help in both anxiety and palpitationWishing you a speedy recovery Good luck </s>