[QUOTE=AnnieB3;930479]

wild_cat, That is a very dangerous situation, having such wide swings. I would make sure that they don't assume anything and check out all basic body functions. The endocrine system can cause issues with heart rate too! It might be a good idea to see an endocrinologist to rule out any other condition.

Thanks for your concern, Annie. At present I'm still having trouble getting anybody to take me seriously on this, despite the objective readings. The cardiologist suggested my wide heart range is due to an exceptional level of core fitness, which stumps me because I haven't been able to any form of cardiovascular exercise for three years. Since my GP voiced concerns about MG and CSH my case has been passed onto a more 'senior' GP who reassures me my symptoms are all a figment of my imagination. So, I will see about asking about this - wish me luck!