When I am sitting or standing, at any time, I sometimes get a very strong irregular heartbeat for about 2 minutes and then it returns to normal. During the irregularity, I feel a slightly tighter sensation and my actual pulse in my throat, it only happens about once a month and I ve had it since I was a small child, I have no clue what it is, I don t have anxiety or any other medical problems. I can see my rib cage moving to my pulse during these, I have no idea what they are and was wondering if you could help, thanks x