Thanks for the replies. I in fact have to update the situation. The hospital have now confirmed that initially they suspected a serious heart attack, but now say he did not have a heart attack, but had heart failure (his arteries etc are fine and seemingly unaffected). He will now be tested to see if they can locate the problem (afraid I am cynical about conventional medicine in some respects so I don’t hold great hope here - but do very much respect their efforts).
I should add that 18 months ago my father was treated for Acromegally (excess Growth Hormone) caused by a pituitary tumour. He did not have chronic health problems from this but he was strongly advised that it would damage his health if left untreated (he had probably had this for 30 years - the guy has huge hands lol!). Would have been huge if he’d trained too! I used to joke I wanted to get him on the weights because he had great genetic potential. Anyway, I digress…The op went well according to the docs and he made a good recovery. Acromegally can apparently affect the heart but as I said, every test done showed all his profiles to be in very good order (he’s had an active job, very lean, better than average diet, active).
Then he was struck down with this mystery virus during which time he was pretty seriously ill for 2-3 months. To be honest, since then for the past 6 months he’s got better but lost a bit of muscle mass and hasn’t looked as healthy. And - importantly they never diagnosed the virus (confirmed this today from my mum).
So we have a bit of a health puzzle - could be the medication, could be the operation/hormone problems, or as i suspect it could be virus related (which may be caused by the aforementioned hormone issues)…
again, thanks for your help guys.