Go for Gall bladder stone test, serum bilirubin and
liver function test first of all....
These symptoms especially lot of belching comes mainly in GB stone and liver issues. If reports come normal then it's very easy to treat you.
Right now your heart reports are normal but if your prblm didn't resolve timely then this will lead to heart problem in future. I have solved many such cases. See...vagus nerve, sympathetic nerves, cardiac nerves, auerbach plexus and Meissner plexus are all connected to each other..so problem in one leads to problem in other area supply also with time. You better consult here for proper pin point treatment.
Next Steps
consult here online.