Collateral Vein(S) & EF

[HeartTwo]

Would an expert please advise the relationship between the growth
of multiple collateral veins and the EF readings?
Logic would suggest that collaterals may cause a favorable EF
reading when in fact, a patient could have severe blockage.

[ed34]

I think the best expert on here regarding collaterals is Kenkeith. he is quite knowledgeable on the subject so hopefully he will spot this and just in. For my input, you do realise that collaterals are not veins? They are more like arterioles, tiny arteries. Remember, arteries carry oxygenated blood to living tissue, while veins take away used blood back to the right side of the heart to be sent to the lungs.
I'm not really sure if the EF would be affected by collaterals. I believe if blood flow is adequate in heart tissue, there would be no collaterals. If oxygen lowers, you may develop them to make up for the oxygen loss. When treatment is given, the collaterals will probably shrink back down and close up again. So, collaterals dont act as an additional supply, they simply make up for a loss, meaning the overal balance is the same, or slightly less.

[ed34]

I think i misunderstood your question, sorry. The above still stands but if someone develops a severe blockage then yes, the EF should remain around the same if collaterals form. However, let's say you develop a 95% blockage in the LAD. Not everyone develops collaterals that give the missing 95%, some will only get enough oxygen to keep the heart happy in its relaxed state, i.e. 68bpm. This is what happened to me. My LAD was 100% blocked at the top but thanks to collaterals, enough oxygen was given to keep the tissue alive, but not enough for exertion. They fed into the bottom of the LAD so blood was flowing up the LAD instead of down and the vessel was so thin it could hardly be seen on an angiogram. So not everyone develops collaterals in the same way. Some people develop quite large collaterals, giving enough oxygen for exertion.

[HeartTwo]

Thank you ed34! My situation and experience may be quite unique. The "condensed" version is this. I was diagnosed with severe blockage and quickly underwent 4x CABG. One of the cardiologists informed me that 3 were 100% blocked and the other about 50%. All 4 were replaced. No symptoms at all.
Originally diagnosed with blockages in 1995 and was put on Med's. In reviewing the cath procedure notes of 1995, I read where multiple collaterals had formed. My EF was within range and I exhibited little to no symptoms. Logic suggests the collaterals did their thing otherwise, it may have been lights out for me.
A fair non-medical understanding of the formation and growth of collaterals strongly suggests they grow out of near sheer luck. It may be a defensive mechanism the body uses to stay alive however, not all people can grow or, have the ability to grow the collaterals. I have read the Academy of Arts and Science as well as the American Heart Association articles on the subject.
Lacking solid evidence to the contrary, is it fair to say "collaterals" will and can keep you alive IF your body can grow them?  As we know, not every patient has the ability to grow them.
I would really appreciate others chiming in on this matter and, ed 34, once again Thank You.

[ed34]

"Lacking solid evidence to the contrary, is it fair to say "collaterals" will and can keep you alive IF your body can grow them?  As we know, not every patient has the ability to grow them. "

You are correct. I met someone in a heart hospital who lost 30% of his heart tissue because he didn't grow any collaterals. Your case is similar to mine because if we didn't grow them, we wouldn't be here typing in this forum.
There does seem to be a variety of situations with collaterals, such as....
Some people don't grow them. Some people form them but only small enough in diamater to allow heart tissue to remain undamaged at rest. Some people grow fairly large ones and my cardiologist said some are large enough to be teased open to accept a stent, to act as a natural bypass.