Thanks for your question on Healthcare Magic.
I can understand your concern.
Since you are having history of ASD (
atrial septal defect) repair, we should first rule out heart related diseases for your symptoms.
So first get done ecg and 2d echo.
If both of these are normal then no need to worry for heart diseases.
Other causes are asthma, stress or
anxiety.
So
consult pulmonologist and get done clinical examination of respiratory system and PFT (pulmonary function test).
If both of these are normal then no need to worry for asthma.
Sometimes, uncontrolled stress and anxiety can also cause similar symptoms especially in teenage. So
consult psychiatrist and get done
counselling sessions. Try to identify stressor in your life and start working on it's solution.
You may need anxiolytic drugs too.
Don't worry, you will be alright. But first rule out heart and lung diseases.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.