That's what I was told too. What I can't seem to establish is what happens to the blood vessels themselves. Let's give a simple scenario....
A patient has a heart attack, angiography reveals a total blockage to an area of the heart muscle. The blockage is stented then blood can flow again. But would it? Would the blood vessels still act as conduits of some kind, or be permanently collapsed? If the blood vessels still allow blood to flow then a perfusion scan would show good vascularisation, if they do not, then it would show as dead. Either way, a viability scan would reveal dead tissue.
I think my confusion comes from a comment my cardiologist made, which is a kind of contradiction "If I stent the LAD and the tissue is dead, it would be a waste of time because the Oxygen isn't needed". This seems to point to the idea that the blood vessels survive much longer. I believe heart tissue has a life of about 40 mins when starved, but I have no idea how long blood vessels can last. This begs another question too doesn't it?
When an emergency procedure is called for on a patient, some of the collateral vessels, if developed, are too small to be seen on angiography. Mine showed clearly on a perfusion scan, but nothing showed on angiography which is why they thought the heart muscle was probably dead. How do they make the decision whether to stent or not when they don't see the whole picture? The call could be enough to create tissue damage or save it.
Wow, three years later and still so many questions but ones I should have thought of in the beginning I suppose.
My understanding is that blood will not always pass through damaged heart muscle, even after intervention. I have asked that question and was told that dead cells no longer have the ability to absorb blood, the small vessels no longer exist once the cells die and there is no way for oxygen (or the tracer) to pass from blood to cell.
I have not read that anywhere, it's what a Cardiologist told me. Maybe someone with more knowledge will respond.
Jon