Thanks for your query .
From your test reports you have told it is more unlikely to be a cardiac issue .
It could be a gastric issue since you have burping and
constipation .
What is requires is a lifestyle change ,
Dont skip meals
Increase fluid intake according to your body weight and level of activity.
Cut down dairy products
Eat a plant based diet-Lots of veggies and fruits.
brown rice , oats , okra , peas , figs , prunes , raisins all add to fiber content
dont sit for long hours Keep moving for your bowels to move
Dont smoke ,No soft drinks and no alcohol
Reduce
stress ,reduce oil and spicy food
Cut down caffeine .
dont eat processed food .Cook your own food
Dont eat within 3 hours of bedtime
all these things will help you solve your problem.If you persist to have symptoms you might require
endoscopy agter Gastro enterologist consultaion
Hope this helps