Ischemia 2 months after bypass

My father had his second bypass surgery - the first 16 years ago.  He had his second in April.  Did the rehab and just as he was about to finish, developed some arm pain and a little chest tightening. He had a nuclear stress test and it showed a "little slower blood flow to the back of his heart".  The cardiologist is treating him with medications.  He still has some arm pain with exertion.  Do you believe he needs further testing.  The doctors just said for him to take a nitro when he felt the pain.  He does and it takes care of it and he is able to keep working.  He is 80 years old and pretty active.

[ed34]

Sounds like there's still a blockage in an artery, maybe the LCX. If nitro helps, I would continue with that and see how he goes. If it gets to a point where nitro has very little effect, they may go to the next stage and perform an angiogram to see if a Stent is possible. If he suffers no discomfort at rest and the nitro works for exertion, then there will be no muscle damage.