Gallstone?
To eat and not sit or lie down, for an hour would be a terrible problem for me...
Your vagus nerve may have been stimulated with the teeth cleaning...and your heart is on that "circuit" as well as gallbladder, and intestines... That is why ppl with heart attacks often die on the commode. They get symptoms of THE many things, on that nerve.Many heart patients die because they mistakenly believe it to be gas, and delay care.
I am glad you don't have much more time left before you see the Doc.
I would be sure to question, if Dr. thought heart check prudent, since the pain goes up to shoulders and then down arms... Women do NOT get same symptims men do. They often present differently. ..but sounds much like ulcer or hernia as well, since attacks are linked to meal and positioning.
I had several episodes of awakening with terrrible pouch pain, center of epigastric/ where ribs join. Mine turned out to be an early ulcer.... was treated a few weeks ago, and it has repeated... I found I can take several tums, drink an ounce of lactose free milk, eat a few dry crackers, ....any one, of the above, it stops..so i am back on Prevacid for another few more days....
A late snack might keep an ulcer from attacking your pouch. ..you could try putting your head UP.. to sleep at least 20 degrees, think like 2 really thick pillows, placed down behind your shoulders, and another one to support your neck, and head...