What else could be causing excessive burping, chest pain, and right shoulder pain?

[mrapolasjr]

I'm currently very frustrated.  I have had recurring pains in various areas of my middle to upper chest (especially when pushing down on my sternum), excessive burping (sometimes to the tune of many each minute), upper right shoulder pain which won't go away, and am very uncomfortable in certain positions, especially while driving.  I have had both an endoscopy and HIDA test done, and the results were basically clean.  What I'm trying to figure out is what else could possibly be a cause of these symptoms, whether gastoenterological related or not.  My concern is naturally that there is something cardiac-related going on, but it's tough for me to figure how that could cause all the burping.

Any advice, especially if there are other gastro tests I can take, would be greatly appreciated.  Thank you...