Thank you for your query.
You mention that your son's investigation of X-ray and EKG are normal and the holter report is awaited. That there is a family history of hardening of arteries, under developed valve and tachycardia
. If he has tachycardia (increased heart beat) then the EKG report should have mentioned it. I will suggest that you get an echocardiography
done too which is going to give us an indication of the valves. Kindly also get his blood biochemistry work-up done to know the lipid profile
in view of the family history of hardening of arteries.
Apart from doing a cardiology workup, respiratory cause should be ruled out. If these turn out to be normal then a workup to rule out endocrinological causes like hyperthyroidism
need to be done.
I hope I have answered your query to your satisfaction.