Heart Cath test

My husband will have a heart cath on Tues.  I know the test will show any heart blockage.  Is there anything else the test will show?  Does it show heart damage or anything else that would cause chest pain, involving the heart?

What kinds of questions should we be prepared to ask?

My husband had the heart cath two years ago, but has daily chest pain, and the stress test results were non-conclusive.  Last time they did the test they did emergency 9-by-pass surgery.  He is very nervous about this test.  Any information you would give us would be helpful.

[CCF CARDIO MD - DLB]

A heart catheterization will show what his own coronary arteries look like and will also see if his bypass grafts are still working. It can also show whether the heart is pumping blood normally or whether any severe damage has been sustained.