What is Atrial Fibrillation?

This is a personal insight into what Atrial Fibrillation is, its mechanism, how it feels, what it looks like, and how it affects you. More specifically – my experience – understanding at this time – and a place where I can write it down to refer others to as explaining gets really tiresome.

Atrial Fibrillation (AF, or Afib) is an arrhythmia – a rhythm problem of the heart. It affects the way in which the top two chambers function. As a direct result of this dysfunctional behaviour, it affects the regularity and efficiency of contraction of the lower two chambers – the ventricles.


If your car engine was to fire in the wrong order, or the Otto Cycle took a day off – your car would not run as intended – so its a bit like that.

I am an engineer by nature – so let’s try and explain this in terms of us as big old salty moist meat bags that by the miracle of biology do not jerk around like frogs legs under a battery.

The hearts pumping motion is started from a single point in the top right atrium – the sinus node. It is then conducted around the top two chambers – which contract in response – reducing in internal volume, thus pushing blood downwards, through a valve into the bigger chamber below. As the electrical pulse rounds the atria, this signal hits a sensor that sits in the floor of the right chamber. This sensor then triggers the contraction of the two lower chambers which squeeze the blood out with considerably more force. Thump – THUMP and then they actively return back again.

Precharge, fire, relax again, repeat. So – there we are – a 101 of this fancy fluid pump. But as with all things, closed systems or otherwise, things can go awry or even stop over time.

With AF – another point in the heart has decided it wants in on the party and is generating its own signal. As with most forgeries, its probably not as well thought through as the real thing – a bit of a knock-off copy. As a result, it all gets a bit electrically confusing for the top two chambers. Various interference patterns occur, and rather than triggering a solid, single contraction – you get all sorts of patterns. The electrical patterns of both interference and amplification waves very much like a Ripple Tank from Physics at school. These confusing, conflicting patterns cause the muscle to trigger – not in one solid motion but to quiver rapidly.

Periodically there will be enough charge, in the right place, to trigger the bottom two chambers – irrespective of whether they have been filled, it is the right time, or even if they are ready to contract. So while blood is moving through these, it is generally devoid of pattern and form.


The most common cause or source of all this disruption is the sheaths of muscle around the pulmonary veins where they enter the heart.

Contrary to everything you ever learnt at school, or in First Aid class – these veins are carrying the thick red stuff directly in from the lungs. Four of them. In a bundle into the left chamber. For whatever reason, they have been far too stressed about something – and they now believe it is their time to shine.

This is suboptimal. This is AF.

What is it like?

At this point, you are, amongst other things, inefficient. The regular delivery service of your internal pump is now somewhat more ad-hoc, and you are moving 20 to 30% less blood with each cycle. As a result, you are likely feeling faint, there is likely localised discomfort and a sensation which I have heard best described as a sizeable fish flapping around inside your chest.

It is hard however to impress upon someone outside of your chest what this is like. I remember the first time when I was able to say “put your hand there dear, and you will feel my heartbeat” – and to see her recoil in horror… then put her hand back. NOW she understood.

The best way to paint a picture is to do what the professionals would do – use an ECG/EKG. So below are two real-world examples of your’s truly.

First example – here I am getting occasional issues, and I am trying to catch one with a small device I have. I am up and about – making dinner as it happens – chopping vegetables – but as you can see I am relaxed and everything looks very regular.

Note the pattern: small bump, big spike, wider bump. All of this is quite regular. It is a regular pattern, like a rubber stamp, some variation and the spacing is regular too. You do not have to have a great understanding of what you are looking at short of the small bump is the thump, and the big spike is the THUMP. Small chambers, big chambers, and the bit afterwards is it resetting again for the next one. Order. Spacing.

Second example. This is me about an hour after I have gone to bed. Having felt increasingly unwell I turned in for the evening. So I doing nothing, lying still, waiting for sleep. But it is not happening.

As you can see below – there are a lot more beats. The shapes have changed, the spacing is different too. The only part that is almost the same is the spikes. As discussed earlier these are the ventricles pumping because they have been asked to – irrespective of whether they are ready, and without any rhythm. The small bump before is mostly gone, although you can see it many times in the gaps between the spikes – this is the top chamber quivering.

About 4 hours after this started I checked myself into A&E – and as if by magic it stopped as quickly as it had started.

This is the blessing with Paroxysmal Atrial Fibrillation – or PAF is the type that comes and goes. There are single events, and there are permanent suffers. There also seems to be a progression from one to the other, as I would attest to. Starting off with single one-off events years apart, then a longer event, then years later another day-long event, and then nothing….. before returning weekly, sometimes many times a day. It progresses.


So what causes it?

Stress. Stress to the heart, for too long. Apparently. Stimulant such as caffeine and alcohol (to the point that “holiday heart” is a phrase used to refer to single isolated instances for obvious reasons) can make things worse and trigger events. Unsurprisingly battering it with prolonged efforts (which is why otherwise fit cyclists, rowers, and cross-country skiers shine out from the stats of the older generations) will equally upset it.

So – I like my coffee, I like my beer, I like to push myself hard, I also like to – wherever possible combine these three into a hedonistic cocktail with friends whenever I am able. Oh, Oh dear.

So – now that you have an image of me as a sadomasochist with a booze problem – which while it amuses is not true to form. As this was not the only trigger. Sometimes – just relaxing would do it – more often than not it would come on with sleep. BUT sure enough if you wanted to summon the demon (through the wisdom of hindsight) – get really tired through exercise, drink a bunch of coffee the next morning, exercise hard again, then numb the pain with a drink of four, stay up late and laugh hard with friends – repeat as necessary…. spin the chamber and pull the trigger. All of which being textbook irritants. Regretfully – for whatever reason – now – cutting out triggers has had little no effect – however taking them all on at once is not something I am keen to do at all anymore…. it is just not worth the risk – as fun as it may be as a lifestyle choice.

To Conclude

Having read a bunch of stuff from a host of sources, speaking with some fantastic medical and support professionals, this is my understanding of the forces at play here. How it feels, the mechanics, and what is going on when they wire you up and draw on the chequered paper.

Now chances are – I have probably got a bunch wrong here – read the wrong things – interpreted things the wrong way – if so I am sure someone will correct me, or I will correct me when I realise… but this is not my thing – I am just a guy trying to understand what is going on inside his own chest and share that knowledge as I know I scoured the internet for whatever I could when I was first diagnosed.

Foolishly I pretty much stopped exercising and accepted my fate – but realistically – with the right medication, advice, guidance, monitoring – life can go on. In fact – you may find yourself even more motivated to get out there. Sure – you may have to adjust – change your goals – what you do – be realistic – but it’s all good, it can nearly always be worse, and modern medicine is making great advances day by day.

PLEASE do realise this is one guy sharing his experiences and accrued knowledge right or wrong – I am not a medical professional – and if you are worried or concerned – go find one. Okay? But if you were wondering what it’s like – how it happens – trying to find out what the words mean – have a new diagnosis – this should start you off down the road or bolster what you have already found out there.

Now – go take your tablets – go do the good things – go get while the going is good!

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