Yes, I was diagnosed with this condition 3 years ago! It was the 2nd Cardiologist that diagnosed me. The 1st one I went to put me in hospital for an Angiogram which came back absolutely clear. He told me that my arteries were like a healthy 14 year old & that my BP was perfect 120/65 & my cholesterol was low with a perfect balance.
I had been getting angina pains at the Gym- it always cut in at the same point! The 1st cardiologist told me to ignore the pain & carry on exercising- but it was far too scary to do that!
The 2nd cariologist I went to sent me for a different test- which I cant for the life of me remember the name of! They injected me with radioactive stuff & then I did a stress test until I felt the angina- then I was immediately put in a scanning machine so that they could view the tiny vessels that are involved. This is how the diagnosis was made.
I was then put on a drug called Imdur- 60mg taken in the morning. I am pretty well controlled now but I carry around the the nitro spray just in case. I have only had to use it twice so far- both times when I was hurrying in the heat (I live in Australia) It hasn't affected my life really- I feel much better now that I have been assured that it isn't a dangerous condition! If I have to take the nitro, I just do - & that's fine too.
I don't think they know why people get it,- but it's pretty rare I think. My 2nd cardiologist was interested in the fact that I'm an asthmatic & said it could be triggered by an abnormal reaction to adrenalin. But I have had asthma all my life & this started happened 3 years ago. Who knows?
Best of luck