It is extremely rare. I have an artery that spasms. It can collapse and looks like a piece of paper or to the point of a slinky. 5 heart caths showed each one in a different way. Mayo - Dr Amir Lerman and Dr William Mauck have been amazing. I'm on a lot of medication and have a Spinal Cord Stimulator. However there are some people having been diagnosed with it and they are having a lot of problems getting help because of the rarity. I've had 2 heart attacks and I follow all Drs orders to prevent another one. The symptoms can be the same as a heart attack however if I have a bad spasm it backs up my blood causing other problems