Hi, i am really searching for an answer on heart palpitations. I am a healthy 40 year old male, i exercise and do crossfit and run. But for some odd reason i can be just relaxing and without warning i get this upper stomach squeeze that takes my breath away and makes me feel like passing out . And when i feel my pulse i can feel it skip beats or a long hesitation before the next beat, that s when i get that stomach feeing that takes my breath away. I feel real tired aferwards like a did a days work. i have seen a heart doctor, and its hard to do a heart monitor holter, since it might not happen for a month till all of a sudden. but it is really a scarey feeling. Once it was so bad that i thought my heart isn t going to start beating again, there was such a long pause, I thought i was done for. Breathing in cold air can activate it like crazy. Been in the ER for it but by that time all looks normal on the monitor since i won t be having the symptoms anymore. Answers or ideas what could be causing it? I can t drink pop because that will trigger it to, but it can happen randomly. When i exercise and have my heart rate up it doesn t happen