I am so sorry to hear about Nick's ongoing struggle. I hate to see anyone that young, receive the dose of radiation that goes with the contrast dyes used during a cath. I have had 8 cardiac caths myself, but I am 53. I have a congenitally "insignificant right coronary artery" which is too small to stent. It supplies very little blood to my heart.
Your son is on many potent medicines, so take this with a grain of salt. I researched the vasodilators, a few years ago. I was started on timed released nitroglycerine, Imdur, due to angina. I read somewhere, in theory this could promote "collaterial" artery development. As you know, collateral arteries can form natural bypasses, but usually not enough to support an active lifestyle. Imdur will also lower your BP, so your son may not can take it. It does have some troubling side affects especially for a couple of months. I have stopped this med, because I take way too many others.
It's a shame that the small left coronary arteries were not discovered earlier, unless the docs thought he was at an age where they could have been small. I am sure they probably use as little contrast dye as possible with him. They probably are also in a hurry to finish the procedure due to his age. I believe that some intervential cardiologist miss some details of our coronary arteries during a cath. It is documented that this has happened before, although the procedure is the gold standard.
It would help his Lca(s) to grow if he could exercise, but that is out for now. I have 3 stents in my Lad and 1 in my obtuse marginal. They wanted to use my left mammary artery to bypass the 95% blockages. I chose stents and rotoblational arthectomy 4 months ago.
A doc that used to post here told me that thoractic surgeons always wanted a good "target" to graft into, i.e. Nick may not have a good target.
He has had soooo much surgery that it is becoming hard to do again. The old fasion 12" scar and having your ribs sawed open is tough. That is why I am running from it. I have researched websites like and really only one that seems to speacialize in this area and it is a minimally invasive type "keyhole surgery" It has a proper descriptive name, but I forget what this type of surgery is called. THE MOST IMPORTANT thing about this surgery is it is hard to repair anything BUT the Left coronary arteries. This is beating heart surgery. A small incision is made in the cartilage between the rib cage. A mammary artery is disconnected to where it went, and grafted into the best artery available (his dominant left). The mammary artery is known as a "native artery" and does much better than veins removed from other parts of the body. Recovery time is much quicker.
I don't know who has done your son's surgery, but I would go directly to the Cleveland Clinic. They have a very user friendly website. They also specialize in receiving medical reports from your doctors and rendering a second opinion. The cost is not that much and your insurance may cover it. It's around $500-$600. I really suggest you get help from all of his previous docs in gathering his medical records and contacting the Cleveland Clinic. You can also make appointments and have any necessary procedures done. I think they are also in Florida.
I don't believe that having cut some of the muscles in his chest will mask all of any possible angina associated with his condition. He has had so many procedures, he probably doesn't remember how a normal chest feels though.
If his BP is not low, ask about fast acting nitro which can prevent a heart attack. I have lived with it for years, at times. If your BP is low, the nitro can cause it to fall so low that cardiogenic shock can occur.
G-d bless Nick,