If you want input from other patients, perhaps you should pot in the community area:
http://www.medhelp.org/forums/Heart-Disease/show/72?camp=msc
Meanwhile, has you seen a rheumatologist? Could it be Costochondritis?
Jesus
I'm sorry that you have been gong through such a difficult time with symptoms that have not been controlled (or diagnosed). On the optimistic side, however, is that if you had a complete and thorough cardiac work-up (ECG, blood work, echocardiogram, stress test, and even a cardiac catheterization), you can be reassured that this is not coming from an underlying condition related to your heart.