On And Off For A Couple Years I Swear I

On and off for a couple years i swear i feel like my heart thuds in my throat, like a pause, bot a skip it does not have to try to catch up and i feel fine when it happens, sometimes i feel like i havs to cough. Ive had ekgs and ny dr sat with a stethoscope and tries to seenif he could hear anything... But nothing any ideas