I am puzzled why the doctor did not explain to you the reason for a heart catheterization
. Of course it must be related to why your son needed to go to a cardiologist in the first place -- symptoms? Prior diagnoses?
Generally speaking, a heart catheterization is performed to assess coronary arteries (#, locations, any narrowing), heart valve (leakage or narrowing) or heart muscle (thickness, movement, or any holes where there shouldn’t be one).