Hello You didn t mention your age and the side , where you are having pain but ECG is normal means at present we can rule out heart disease. Your doctor prescribed mosapride with methypolysioloxasane as this act as antiflatulants and used in hyper acidity cases. In my opinion all these symptoms may be due to these reasons , these include; 1 Hyper acidity or chronic gastritis , diagnosis can be confirmed by upper G I endoscopy. Try raising the head of your bed about 4 inches with blocks . To control stomach acid avoid eating or drinking for 2 hours before you lie down. It also might help yo avoid drinking alcohol or drinks with caffeine in them or eat chocolates or greasy or oily foods . Also take some antacid ( but if it contains oxetacaine will be better ) but if pain is severe you may need drugs like pantaprazole-D once or twice in a day on empty stomach. Over eating is the another causes of such symptoms , so avoid it . Tension or stress are the most common reason of such symptoms ,so be careful about that also. Hope this will help you.