Most likely your symptoms might be due to GERD. You can be reassured that it is not due to a cardiac problem since your EKG and ECHO are normal. You might want to take Omeprazole
20 mg one tablet half an hour before breakfast daily for a week. Omeprazole is a proton pump
inhibitor and reduces the acidity.
I would suggest that you do not lie down immediately after eating a meal. Preferably wait for at least 2 hours after having a meal before lying down.
Avoid fatty and oily food.
Have frequent small meals rather than 3 large meals a day.
I would also like you to get certain blood tests like complete blood picture,blood sugars and thyroid
function test done as anaemia
, low blood sugars, thyroid disorders may sometimes present with palpitations.
Hope this helps.
Dr. Divya Kuttikrishnan