Hi Chris,
I have experienced these and was put through some tests, my hubby too. It feels exactly like a heart attack doesn't it and is very frightening.
The doctor said it was caused by a spasm in the oesophagus and can mimic a heart attack.
My husband finds that drinking soda water helps to make him burp and that eases it but he has to lie down till it eases.
I take a combination of a spasmonal and gaviscon and a pain killer. Not really sure which helps but who cares?!
Sometimes, if i catch it quick enough I have found exercise ie walking the dog heps.
Could be acid reflux too. Do you take a stomach protector?
YES I'VE CHANGED, PAIN DOES THAT TO PEOPLE.