Fascinated to read the experience of palpitations with acid reflux. My experience is simple and I am hugely relieved to read others' experience. For hiatus hernia - caused I am sure by severe coughing - I was on 15mg once a day (35 mins before first food) of Lansoprazole (for life I am told) until another issue led to the doctor upping it to 30mg in January 2017. Within days I noticed frequent "missed beats" from 3 to 4 times a day to sessions lasting half an hour. I reverted to 15mg and all that stopped within days. Having run out of 15mg I am currently using 30mg again and, within days, I am back to constant "missed beats". My reflux/indigestion symptoms are completely relieved by 15mg and doctor was happy I revert to 15mg.
My experience suggests that for me my palpitations are wholly due to the higher dose of Lansoprazole as any other possible causes, as far as I am aware, are not present.