I have the same exact symptoms as you. Have been to the er several times and all of my heart labs and all my other labs were fine , They kept me on the monitor for 4 hrs watching for anything different, everything was fine. Like you I tend to have this when bending or some types of movement it is a very strange feeling indeed. It seems to happen when my gerd is acting up . I am going to follow up with a cardiologist and wear a heart monitor just to make sure. It is very frustrating as well as very scary when this ocours. I also sometime feel like maybe it is gas up in there rolling around too .. So like you I am clueless also!
Edit: I gave your thread a title 
Post Edited By Moderator (stkitt) : 4/26/2011 8:16:48 AM (GMT-6)