I have atrial fibrillation, as does Mark Spitz, the record-breaking American swimmer.  Mine isn’t as dramatic as his, mine was simply discovered when I went to the doctor and she listened to my heart.

“You have an irregular heartbeat.” she said.

“I know, I’ve had it for years.”

“We really should do something about it.”

That’s why I hate going to the doctor – I always come away with more than I take in.

I have an International Normalized Ratio (INR) test every few weeks to see how my blood is clotting. I need this because the doctors make me take Warfarin to stop my blood clotting too quickly. Until a few years ago I thought of Warfarin as a very effective rat poison.

If you have a normal set-up you have an INR of around 1. If you have atrial fibrillation they try to get it in the range 2.0 -3.0 which stops it clotting and prevents strokes and heart attacks. If you have a mechanical heart valve they like it to be a bit higher. It’s nothing special, a million of us have it in the UK and ten percent of the over 75s have it.

However, it can be a bit variable, and you may have noticed that I often complain about the testing, as the results can be very imprecise, which annoys me. I do my bit – eat a dull and unvaried diet, take the pills at the same time each day and let them take regular bloods. They, on the other hand, don’t do much, as I recently pointed out to them.

So, I believe I had got as far as 3.5 for people with mechanical heart valve and similar problems. The next step is 5.0 – 8.0. They start getting twitchy at this sort of level, particularly if it is accompanied by bleeding, and start threatening vitamin K injections. At 8.0 they start getting very twitchy . . .

And at 9.6, if you haven’t admitted to any bleeding, they tell you to stop taking the pills immediately and to go for another blood test in two day’s time.

I’m not sure whether to worry or claim it as a personal best.