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2 March 2023

What’s the difference between Atrial Fibrillation and an irregular heartbeat?

Atrial Fibrillation And An Irregular Heartbeat

Dr Katie BlogWritten by Dr Katie Stephens, GP

Dr Katie graduated from the University of Manchester in 2007 (MBChB) and completed her GP training in the West Midlands in 2012 (MRCGP). 

 

Atrial fibrillation (AF) is a relatively common, specific type of irregular heartbeat. In AF, the smaller two chambers of the heart twitch and shake non-stop instead of beating normally. This type of movement is called fibrillation. The two chambers affected are the atria (plural of atrium); hence, atrial fibrillation. By comparison, ‘irregular heartbeat’ is generally used as an umbrella term for any type of heartbeat that isn’t the usual, regular lub dub… lub dub pattern. Another term for this is ‘cardiac arrhythmia’, or ‘abnormal heart rhythm’.

There are lots of different types of irregular heartbeats. All cases of atrial fibrillation can be considered irregular heartbeats. Not all irregular heartbeats are due to atrial fibrillation. Understanding the difference between AF and other causes of irregular heartbeats is important, as both the knock-on impact on the body and the options for treatment will be different.

Atrial Fibrillation

The heart relies on electrical impulses to make it beat normally. Usually the top two chambers of the heart beat first, pumping blood along to the bottom two, larger chambers. When the bottom two chambers then beat, blood is pumped out to the lungs and the rest of the body. It then usually has a short pause to start to fill up again. In AF, there is disorganised electrical activity in the top two chambers. This causes the rapid and uncoordinated twitching here instead of proper contractions or beats. The larger two chambers are still able to squeeze/beat properly, but their pace then becomes irregular and chaotic.

Atrial fibrillation can be dangerous for three reasons:

  1. It causes the blood flow to be turbulent instead of smooth. This increases the risk of a clot forming. If a clot gets pumped out of the heart and goes to the brain, it causes a stroke.
  2. It often leads to the heart beating too quickly. Normally the atria set the pace of the heart rate. The larger two chambers in the heart (the ‘ventricles’) beat right after the atria, giving the lub dub… lub dub… lub dub pattern. (The atria make the ‘lub’ sound; the ventricles make the ‘dub’.) In AF, while the atria are shaking instead of beating normally, the ventricles lose their usual rhythm and tend to beat too quickly. Or, in some instances, they beat too slowly. This can cause a heart rate that is so fast (or slow) that it leads to poor blood flow to the body, which is dangerous.
  3. It increases the risk of heart failure. This is when the heart doesn’t pump as hard as it should do. This can have serious knock-on effects on the rest of the body.

Irregular heartbeat

As above, an irregular heartbeat is generally anything out of the ordinary, regular rhythm. Other terms used include ‘abnormal heart rhythm’ or ‘cardiac arrhythmia’. Strictly speaking, some types of abnormal heart rhythms still have a ‘regular’ rhythm but are abnormal because the pace is too quick or too slow, or not traveling through the heart like normal. However, to keep things simple in this article, we can use the term ‘irregular heartbeat’ in its wider sense to mean any abnormal heart rhythm.

A common example of an irregular heartbeat is an ectopic heartbeat. This is when the heart has just a single beat that is out of sync, before it falls back into its regular pattern again. This can be due to either the atria or the ventricles beating abnormally. While ectopic beats may feel uncomfortable, they don’t usually cause serious problems. Many people have ectopic beats without even feeling anything.

At the other extreme, there are life-threatening irregular heartbeats, such as Ventricular Fibrillation:

Ventricular Fibrillation is when the larger two chambers of the heart (the ventricles) are shaking and twisting (fibrillating) instead of beating normally. This is dangerous as it is the ventricles’ job to pump blood around the body. If they are fibrillating, blood doesn’t get pumped, and the heart essentially stops working altogether. If the heart isn’t restarted quickly through resuscitation, the person dies.

There are many other types of irregular heart beat that are more serious than ectopic beats, but not necessarily immediately life-threatening, like Ventricular Fibrillation is.

Is an irregular heartbeat the same as atrial fibrillation?

No. Atrial fibrillation (AF) is an example of a type of irregular heartbeat. It is only one example though, and there are many other kinds of irregular heartbeat which have nothing to do with AF.

As discussed above, AF happens when the two smaller chambers in the heart are wiggling and twitching (fibrillating), rather than squeezing in their usual controlled way to pump blood. With other types of irregular heartbeat, the atria beat and squeeze normally, but the overall rate might be too fast or slow, or just not regular.

This table highlights similarities and differences between atrial fibrillation and other types of irregular heartbeat.

Feature Atrial Fibrillation Other types of Irregular Heartbeat
Where in the heart is the main problem happening? The atria (smaller, top two chambers in the heart). Potentially anywhere!
Are the atria beating normally? No. They aren’t really ‘beating’ at all and instead have uncoordinated twitchy movements. Generally, yes! The individual beats are more or less normal. (But the speed or regularity might not be, or the electricity might be travelling in a slightly different path than normal.)
Heart rate (how many times the heart beats in one minute) May be too fast, normal, or too slow. May be too fast, normal, or too slow.
Possible symptoms Palpitations, chest pain, shortness of breath, feeling lightheaded, fatigue or no symptoms at all. Palpitations, chest pain, shortness of breath, feeling lightheaded, fatigue or no symptoms at all.
Does it come and go? For some people, yes! (Then it is called ‘paroxysmal AF’.) For others, once it comes, it tends to stay, unless specific treatment is given. Many irregular heartbeats do come and go spontaneously. Some more serious ones need urgent treatment in a hospital when they appear.
What are some of the causes? High blood pressure, alcohol, consumption, obesity, and viral illnesses High blood pressure, alcohol, consumption, obesity, and viral illnesses
How is it diagnosed? The first step is always a physical examination. Often it is picked up on an ECG (heart tracing that records electrical impulses traveling through the heart). For people who have a normal heartbeat most of the time with just temporary periods of being irregular, this can be caught using ambulatory ECG monitoring (wearing a device that records a heart tracing over a longer period of time, such as 24 hours, 48 hours, or even longer). The first step is always a physical examination. Often it is picked up on an ECG (heart tracing that records electrical impulses traveling through the heart). For people who have a normal heartbeat most of the time with just temporary periods of being irregular, this can be caught using ambulatory ECG monitoring (wearing a device that records a heart tracing over a longer period of time, such as 24 hours, 48 hours, or even longer).
What does someone’s pulse feel like? Irregularly irregular. Or, in other words, all over the place, with no real steady pattern that can be felt. Depending on the specific kind of irregular heartbeat, possibilities include:

-Every 3rd beat feels off
-Every other beat feels off
-It feels regular but way too fast
-Regular but too slow
-No pulse felt!

Do you need to thin the blood to reduce the risk of a stroke? Yes, always. (But each person’s individual decisions will need to be balanced against bleeding risks.) Only sometimes.
What are the treatment options? This will vary depending on the individual, and the type of abnormal heart rhythm. Broadly speaking, options include medication, cardioversion (where a controlled shock is given in the hospital to try to re-set the heart), ablation therapy (where the part of the heart involved in the abnormal rhythm is burned), pacemakers and implantable defibrillators (where the heart is shocked into beating normally again). This will vary depending on the individual, and the type of abnormal heart rhythm. Broadly speaking, options include medication, cardioversion (where a controlled shock is given in the hospital to try to re-set the heart), ablation therapy (where the part of the heart involved in the abnormal rhythm is burned), pacemakers and implantable defibrillators (where the heart is shocked into beating normally again).

How does an irregular heartbeat affect blood pressure machines?

If you have an irregular heartbeat, the reading you get from a digital blood pressure machine may not be accurate. The best way to check your blood pressure in this case is with a manual blood pressure machine. This is when someone else inflates the cuff by hand while listening to your pulse with a stethoscope. You don’t necessarily need to see a GP for this – many other NHS staff such as nurses and paramedic practitioners can be qualified to use a manual blood pressure machine. A manual machine will give the most accurate reading for people with an irregular heartbeat.

All of Kinetik Wellbeing’s blood pressure monitors come with an irregular heartbeat detection function. For people who may have an irregular heartbeat but don’t know about it, this feature can alert them to the need for getting checked over.

If you aren’t known to have an irregular heartbeat, and your blood pressure machine shows an irregular heartbeat alert, it is important to speak to someone about this. If you feel otherwise well, please book a routine appointment with your GP.

If you feel like your heart is beating irregularly or your machine shows an irregular heartbeat alert and you feel short of breath, lightheaded, or have chest pain or feel very unwell, please attend A&E immediately.

Both atrial fibrillation and other types of irregular heartbeat can be very serious. Besides the risk of stroke with atrial fibrillation, there is also a risk of the heart beating so fast or slow that it is dangerous. The latter is also true with other types of irregular heartbeat.

Lastly, if you feel like your heart sometimes beats irregularly but you are otherwise well, please book a routine appointment to speak to your GP. These symptoms can be due to lots of different causes, and don’t necessarily mean there is a problem with your heart, but it is sensible to address this.

For more information, please see patient.info’s page on abnormal heart rhythms or the NHS’s advice on arrhythmias.

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