Well, without a detailed clinical evaluation it would be difficult to determine the cause of your symptoms. With GI and cardiac causes ruled out, possibilities that may need to be considered include chest wall inflammation, muscle sprain, costochondritis, injuries to muscles/ ligaments, causes related to the respiratory tract etc. I would suggest getting this evaluated by a primary care physician initially and depending on the cause diagnosed/ suspected, it can be managed accordingly or specialist care may be sought.
Hope this is helpful.
Thanks for the help. I'll be fitted for a Holter monitor on Monday to rule out any arrhythmia, and hopefully finally rule out any cardiac issues. Even though my esophagus doesn't seem to have any obvious problems, it definitely appears to me to be related to GI issues, so I'll be trying some elimination diets at the suggestion of my doctor.
Thanks again for the suggestions.