gas with heart palpitations

For about last 10 years I have had bouts with gas and heart palpitations.  Starts as slight pressure in upper abdomen and then sort of takes breath away.  Heart begins to race and become irregular, 160 beats per minute and can last 3 to 4 hours. I expel alot of gas(burping) during these spells.  Get them 3 or 4 times a year.  No idea what brings them on. Sometimes accompanied with heartburn but more so just bloating.  Had echo,ekg and they checked out ok.  Any help or advice would be appreciated.