After i eat certain foods such as tomatoes, oils, or high fat foods, my resting heart rate goes from 65 to 90-120 for hours. i was diagnosed with gerd. however, i can't find anything about gerd and increased heart rate. what could be happening?

Roemheld syndrome: Swelling of abdomen due to gas is a known cause of increased heart rate. Visit this site for info on abdominal gas: Flatulence: https://www.niddk.nih.gov/health-information/digestive-diseases/gas-digestive-tract/eating-diet-nutrition. Wish you good health!

Does your blood pressure rise substantially during these heart rates? There are endocrine tumors like pheochromocytoma or carcinoid in which certain foods can trigger such symptoms. In addition to Dr. S's comment, I might add that consulting an endocrinologist might be worthwhile.