Thanks Rups - I can't help but feel that we are kindred spirits - our post-stroke experiences are pretty much identical. We should compare head-scans 
Some further discoveries on this topic for those who are affected by it. My GP decided that I needed some sort of statin as my cholesterol, although not too high was borderline enough to keep in check. He put me on Rosuvastatin (10 mg). I had taken a break from Atorvastatin (40 mg) which was causing severe nerve pain in my left leg, and the frequent need to go to the loo. Since then, the dyspnoea has become manageable. So, I am not having it from dawn to dusk, but only when fatigued or anxious. I still get it, and sometimes it's an effort to take that "cleansing breath" (as one person on here described so perfectly). After going on Rosuvastatin, I joined the Atorvastatin forum which is linked from the NHS Atorvastatin page, and I discovered that breathlessness was a common topic, so if you are having dyspnoea, and it is making you miserable but you need to be taking statins, check with your GP if there is another statin you could take instead. There are four main statins, and one alternative non-statin (I forget its name).