Valentijn
I'm kinda back to the palm on the forehead idea. It always works while the arm thing does not. This CCSVI thing is interesting and I am not sure why it isn't considered more here. I have blood flowing the wrong way towards my brain and this interferes with oxygenation, removal of waste and puts pressure on the BBB.
I think that it was Cheney who said that probably 90% of ME people will have this. If we improve ME then mitochondria function in the heart will improve and this symptom should resolve. My brother who shares my genes and exposures to mercury, has had problems with angina. Do you see your heart response as part of your expression of ME?