My design job is relatively sedentary, but when we have events I am under a ton of stress, usually accompanied with ulcers, and I am forced to work a much more active pace. Both today and during the most recent event 1 month ago, my heart started going crazy, no real rhythm. I felt fatigued and light headed all the rest of the day. During the next few hours I feel like my heart randomly give a hard "push" in place of a regular "pulse". This time i have also had random, very sharp bursts of pain in my chest, they are so intense I usually jump at the onset of their presence. I am 21, no alcohol, tobacco, about 180lbs. Thoughts on causes? should i be concerned?