Hello, there are two possibilities, one is gastritis and reflux, other is heart problem. For gastritis, Avoid fatty, oily and high calorie diet. Have some walk after having food instead of taking rest. Have multiple small meals instead of heavy meals. Have regular sleep habits and avoid stress. Lots of green leafy vegetables, fruits. Avoid smoking and alcohol if any. You can get prescribed tab Pan DSR 40 mg beforebreakfast once a day for 2 weeks. For heart disease, you are already undergoing stress test, which will in all probabilities give answer. So follow above instructions and get stress test done.