Thanks for your question on Health Care Magic.
I can understand your concern.
No need to worry much because your heart and lung related diseases because your work up for them is done during hospitalization and it is negative.
Possibility of GERD (
gastroesophageal reflux disease) is more in your case.
It is due to laxity of gastroesophageal sphincter.
Because of this the acid of the stomach tends to come up in the
esophagus and cause the symptoms of Central, sub sternal
chest pain.
This can also cause gaseous discomfort.
Follow these lifestyle modifications for better symptomatic relief.
Avoid
stress and tension. Avoid hot and spicy food. Avoid junk food. Avoid large meals, instead take frequent small meals. Start
proton pump inhibitors and prokinetic drugs.
Don't worry, you will be alright.
Hope I have solved your query.
I will be happy to help you further.
Wish you good health. Thanks.