I had your exact symptoms 13 years ago. I visited 5 cardiologists, had every test including catheritization and all was clear. I then found a gastroenterologist who did all of the esophogeal workups with endoscopies and probes and it turned out that I had a little gerd but really bad esophageal spasms with some cardio esophageal reflex mixed in.
After experimenting with any and all remedies my solution turned out to be 25mg of Amitrypilene, peppermint extract at night with peppermint capsules, pills and pepperment sugar free
candies to stop the immediate pain.
However at times the spasms became so severe that I had to take .4 mg of nitrostat which immediately stops the pain.
That's where I'm presently at with my symptoms which at least makes it liveable without too much agony but I can tell you that it's been a real struggle in getting here. No heart guy ever mentioned the spasms or the reflex. Both of which raises my pulse greatly. Good Luck, Craig