Thank you for the query.
You did not mention 24hours Holters ECG (if you did not have it performed, you should). Such symptoms can appear due to heart arythmia
which can be missed in the regular ECG. If the heart disease
is ruled out, the next step should be upper GI endoscopy
. It will tell if there is an inflammation of the stomach and duodenum
mucosa. It will also check if there is H.Pylori infection. Hiatal hernia can be ruled out in that way as well.
Your symptoms can be also caused by anxiety or stress and increased acid secretion is due to reflex action. But this can be diagnosed after ruling all other reasons of such conditions out. You should also have checked thyroid TSH, FT3, FT4 and ions levels (Magnesium
You may try Magnesium 400mg a day supplementation.
Hope this will help.