You have had several tests on the heart. I would also consider an echocardiogram. If negative, the heart being the cause is unlikely.
Regarding the GI system - again, a comprehensive evaluation has been performed. The endoscopy would comprehensively rule out many of the upper GI disorders. I would consider more specialized testing - such as a gastric emptying scan, or esophageal motility studies.
An ERCP with Sphincter of Oddi manometry can also be considered. Sphincter of Oddi dysfunction sometimes can lead to your symptoms.
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.
kevinmd_