sounds like your teeth are stressing your heart out.might want to see a dentist and see if you have a bad tooth.
Interesting that the doctors would put something in your mouth to numb it. I can't see the connection.
The best way to see what's happening (if it's heart related) is to wear a heart monitor and then get active to see if you can trigger the chest pain. By the time you got to the hospital any arrhythmia problems may have resolved and they didn't see anything out of the ordinary.
I'm guessing you're overseas(?) Not sure how the health system works there and how difficult it will be to get a heart monitor for a couple days.
Jaw pain doesn't necessarily equate to a direct problem with the jaw
"Typical heart attack symptoms...Pain or discomfort may spread beyond your chest to your shoulders, arms, back, neck, teeth or jaw. You may have upper body pain with no chest discomfort. "
I had to swallow the liquid for it's anesthetic effects to work on my digestive system, not just keep it in my mouth. Also in both experiences I encountered no arrhythmia although I do indeed suffer/(have suffered) from tachycardia due to an extra electrical pathway in my heart although this was cryo-ablated three years ago.
I managed to see a doctor earlier than predicted and he suggested that the problem may be caused by scarring on the cryo-ablated extra electrical pathway although I don't see why that would some of my symptoms.