that is the right term - it happens when there are long term arterial subacute blockages - ischaemia/reduced oxygen flow triggers tissues to release vessel growth factors that will lead to extra artery growth.
Bizzarely this leads to situations where diabetics (who develop lesions all along their vessels, and thus have lots of areas of narrowing) can potentially be more protected from a sudden blockage compared to someone with an area of only one blockage - they have enough collateral circulation that the area of infarct is smaller with less damage resulting
The interesting thing (aside from watching the angio, the technology is very cool), was that I'd previously had a minor infarct and didn't know it on a much smaller artery.
They found collaterals (I think the terminology is right) where the body "bypasses" the blocked artery.