*** Edited:
Removed quote of immediately preceding post ***
Sorry to here your troubles, its no fun at all is it
I actually posted a question about the heavy heart beat on the acid reflux boards (I suffer bad from that also)
Another poster said about certain meds causing palpatations, I never really thought that that was the problem. But after stopping my meds for the acid reflux and quiting coffee and caffine as much as possible it has helped a lot.
Maybe your meds are causing it

My heartburn hurts like hell, but it much rather have that than thinking my heart is gonna explode, my anxiety levels have dropped also.
Dont give up hope, I have a list of symptoms the lengh of my arm, but I wont give up untill I get this sorted, and get back to a normal life. I have been constantly ill for years, finally I feel that I am getting somewhere.
Keep posting here for help, good forums here, a lot of the people know their stuff
Goodluck