Hi sorry to hear about her heart op but this does help my theory of why some people may get ms. I too have had open heart surgery and even though it was nearly ten years ago for some reason I believe that blood shortage in the brain causes ms. Maybe my heart op has nothing to do with this shortage but I do think it is a reason for ms. Also looking into causes of some strokes is because of shortage of blood in brain/ blood clots in brain and people who have had a stroke symptoms are very similar to ms relapses. Sorry if I am going on about this but I really do think blood in brain has something to do with ms.