Atrial fibrillation – what you need to know

By June Shannon Stroke News   |   13th Nov 2018

Stroke expert Professor Joe Harbison, explains atrial fibrillation and the importance of early detection and treatment.

As part of our ‘Prevent a Stroke: Feel the Pulse’ campaign, we spoke with Professor Joe Harbison, former National Clinical Lead for Stroke in Ireland, Associate Professor, Professor of Gerontology at Trinity College Dublin, Consultant in Medicine for the Elderly and Stroke Medicine at St James’s Hospital in Dublin and board member of the Irish Heart Foundation who explained what Atrial Fibrillation is and why it is so important to detect and treat it.

What is atrial fibrillation?

With atrial fibrillation (sometimes called A Fib) your heart beats in a disorganised and irregular way which can lead to a range of symptoms and potential complications, including stroke, permanent heart damage and heart failure.

If you have atrial fibrillation and are not treated, you are five times more likely to have a stroke. Atrial fibrillation is the most common type of irregular heartbeat, with one in four people over the age of 50 at risk of developing it.

Professor Harbison explained that in order to pump the blood around the body the heart beats in two phases. In the first phase the two smaller chambers in the top of the heart called the atria contract and in the second the two larger chambers at the bottom of the heart called the ventricles contract.

When the two atria contract they fill the ventricles with blood. The ventricles then contract and push the blood out to the body. So, the atria fill the ventricles and the ventricles push the blood out to the body.

“In atrial fibrillation instead of the atria contracting smoothly they contract irregularly or wriggle. It is sometimes described as a bag of worms and they don’t do an awful lot of work to push the blood into the bottom of the heart,” Prof Harbison explained.

How does atrial fibrillation cause stroke?

Prof Harbison explained that with atrial fibrillation the blood doesn’t move into the ventricles as normal and this can cause a churning effect within the atria. This churning effect tends to cause clots particularly as the blood isn’t moving anywhere.

“The blood is essentially being churned up which tends to cause clots. These clots can get collected in little side pockets of the atria called the atrial appendage, and when they form a big clot they can occasionally get thrown up and bock a blood vessel in another part of the body causing a stroke or damage to another organ, so that is why atrial fibrillation can be dangerous,” Prof Harbison explained.

Is it true that Atrial fibrillation causes more severe strokes?

Prof Harbison said yes, this was true. Atrial fibrillation does cause bigger or more disabling strokes and approximately a third of all strokes in Ireland are caused by atrial fibrillation.
While it is difficult to measure severity of stroke, as each stroke is a devastating event in anyone’s life, Prof Harbison suggested that one way of looking at it was to calculate how much it costs to care for someone in the first 12 months post stroke. Someone with a more disabling stroke will need a lot more care than someone with a milder stroke.

Prof Harbison said it was estimated that the average cost of caring for someone with a stroke caused by atrial fibrillation was between €30,000 and €40,000 compared to between €10,000 and €15,000 for a more minor stroke.

“In atrial fibrillation instead of the atria contracting smoothly, they contract irregularly or wriggle. It is sometimes described as a bag of worms and they don’t do an awful lot of work to push the blood into the bottom of the heart,”

Prof Joe Harbison, Stroke specialist , St James's Hospital, Dublin

Can anyone get atrial fibrillation?
Atrial fibrillation can occur at any age, but Prof Harbison pointed out that it was much more common as you get older (over 70 years).

He said that while atrial fibrillation was seen more in men of all ages, it seems to be more associated with stroke at every age for women, however it is unclear why that is.

Prof Harbison also said that young people can occasionally get atrial fibrillation which was usually due to a small problem with their hearts or because they are incredibly fit.

“Some very fit people can run into it if they have a very low resting heart beat so, occasionally we meet some young people who get palpitations particularly elite sportspeople. The reason they are getting palpitations is they are getting little runs of A Fib.

“Short runs of Atrial fibrillation that you rarely see in young people is generally not that harmful, the thing that makes A Fib harmful in older people is that it tends to be associated with a stretch in the heart, Prof Harbison stated

This stretch can cause the atria to get bigger which means that there is more dead or unfilled space in the heart leaving more room for clots to form.

“It is more dangerous the older you get, it is more dangerous in women we don’t know why, it is more dangerous if you have got a background of diabetes or heart failure,” he explained.

What are the symptoms of atrial fibrillation?
The symptoms of atrial fibrillation can include tiredness, dizziness, palpitations, chest pain, and shortness of breath, but very often a person living with the condition will experience no symptoms at all. Therefore, it is crucial for everyone aged over 50 to regularly check their pulse for irregularities to ensure an early diagnosis.

Prof Harbison explained that about one in two or 50 per cent of people with atrial fibrillation will not have any symptoms at all.

The good news is that with early diagnosis, atrial fibrillation is treatable.

For more information see our ‘Prevent a Stroke: Feel the Pulse’ campaign, or call the Irish Heart Foundation’s Heart and Stroke Helpline, Freephone 1800 25 25 50. This campaign is supported by Pfizer and Bristol-Myers Squibb.

‘Prevent a Stroke: Feel the Pulse’

Learn how to check you pulse and help prevent a stroke

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