Tough to say without examining you. Duodenal wall thickening can be suggestive of inflammation, and the upper endoscopy would be the appropriate test to evaluate this.
Regarding the enlarged pancreas, you may want to consider an ERCP or MRCP to evaluate the bile ducts to see if there are any blockages leading to the enlargement.
Another thing to consider would be a colonoscopy to evaluate for things like inflammatory bowel disease, colitis, or colonic masses.
If all the GI tests are negative, then you may want to pursue the cardiac route. Any type of discomfort that is associated with exertion should be ruled out for heart disease.
These options can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b