This question arose during a recent, brief stay in hospital. I had my third bout of atrial fibrillation in the last 17 years and went to emergency. They pumped me full of various drugs for the next 24 hours – flecainide, metropol, and amiodarone. None of them made much difference (good to know next time), so they zapped me with a low voltage electric shock the following day and I reverted to regular sinus rhythm immediately. I already knew this, since the shock had the same result five years ago.

So what has all this to do with a cause or its absence? I found last time, in 2007, that everyone is a cardiac specialist, keen to find causes. It’s due to stress, said one. You have a weak heart, said another. Too much exercise, said a third. Perhaps your heart is too big … and on they went. And I too sought for causes. In my discussions with my cardiologist at that time, I suggested excess coffee in the past, heavy smoking, periods of lack of sleep, inheritance … On each occasion, he simply shook his head.

‘There’s no cause in your case.’ He said. ‘You’re a lone fibrillator.’

To explain. There are three causes: heart disease, heart surgery, hyper-thyroidism (Graves Disease). I have none of those. The following data also applies:

Blood pressure: 95/65

Pulse: 46

Calcification: zero

Cholesterol: normal (i.e. nothing bad)

In other words, I have a “strong and healthy” heart, as they said at the hospital. All of this means that the atrial fibrillation is not particularly dangerous for me, although when older (70 plus) the risk of a blood clot in the heart does rise.

Of course, given the well nigh inescapable philosophical and scientific horizon within which we operate, there must be a cause for everything. So if I say there is no cause (as I do), the stock reply is, ‘not yet.’ Or, ‘are you a religious nut?’ But what if there is really isn’t a cause for some things? They just happen despite all the evidence that they shouldn’t. In this situation, that seems to be the case. My cardiologist sure thinks so.