Hello and thanks for the query
With the history provided by you it is difficult to say that everything is OK. Kindly give a detail history:
1. Was Coronary Angiography
done and if yes what does it reveals?
2. Any history of Hypertension
3. What treatment are you taking for Heart attack
or Coronary Artery Disease?
4. Has he was suffering for any stress or neurological problem?
5. Any respiratory tract
Please give a light on the above said queries, so that we are able to give you a clear and detail answer.