I'm back home and raring to go, but I must be sensible and get back to things gradually. Thanks for all your messages and well-wishing. I'm happy to say that no further surgical treatment is necessary, having been stabilised - just a tightening up of the sensible measures we all know about - diet, exercise, low cholesterol level and taking the medication. I will write at more length soon.
And no, Lucy, I didn't write the previous message myself, I dictated it to a good friend over the phone and he posted it for me. I think two weeks' break from the computer has probably done me good!