What is Atrial Fibrillation?

By Angela Hartley on 18 October 2021

What is Atrial Fibrillation?


Atrial fibrillation (AF) is a heart condition that causes an irregular and often abnormally fast heart rate.


You can measure your heart rate by feeling your pulse in your wrist or neck for 60 seconds.  A normal heart rate should be regular and between 60 and 100 beats a minute when you're resting. In AF, your pulse will feel irregular, and may be fast or slow. 


What does AF feel like?


Everyone has different symptoms of AF. Some people have no symptoms at all and often carry on their normal lives unaware that they have AF.


Some people have one or two of the following symptoms, others have multiple. Here are some of the most common symptoms that can occur include:

  • Palpitations - the feeling of your heart racing or ‘skipping’ a beat
  • ‚ÄčBreathlessness - feeling like you are huffing and puffing with small amounts of activity that you’d normally not have a problem with
  • Fatigue
  • Weight gain
  • Insomnia
  • Feelings of anxiety or feeling ‘wired’
  • Cold hands and feel
  • Difficulty exercising
  • Dizziness

What causes AF?


The cause of AF not fully understood, but it tends to affect certain groups of people, such as older people and people living with long-term (chronic) conditions such as heart disease, high blood pressure or obesity. 


Sometimes though it comes out of the blue with no good reason at all!


How and Why Do People Get A Fib?

The Heart Rhythm Society have put together some of the most common reasons that people get AF:

Heart-related problems such as:

  •     High blood pressure
  •     Coronary artery disease
  •     Heart failure
  •     Heart valve disease
  •     Heart surgery (AFib is the most common
  •     complication after heart surgery)

Other problems can contribute to developing AF such as:

  •     Sleep apnea
  •     Thyroid disease
  •     Lung disease or lung cancer
  •     Drinking too much alcohol
  •     Being seriously ill or having an infection
  •     Some people are more likely to get AFib than
  •     others. 

Some people are more likely to get AFib than others. You have a higher chance of getting AFib if:

  •     You are older than 60
  •     You smoke
  •     You have diabetes
  •     You are overweight
  •     You have a family history of AFib
  •     You exercise often and hard

Even people with healthy lifestyles who have no other medical problems can get AFib.

In my private cardiac rehab clinic, there are several people who train with me who have AF, but the most common people I see are:

  • Men over 50 who are highly stressed, often drink high amounts of alcohol and caffeine and exercise hard when they get the time to. These guys tend to find out that they have AF as their ability to exercise decreases and they feel unable to do the same amount.
  • Women post menopause who are struggling with thyroid issues, weight gain, tiredness and feeling just not themselves. They find out about AF with a check up with their doctor about something else.

What is happening when the heart is in AF?


In a normal heat beat, the muscular walls of the heart tighten and squeeze (contract) to force blood out and around the body. They then relax so the heart can fill with blood again. This process is repeated every time the heart beats.


In AF however, the heart's upper chambers (atria) contract randomly and sometimes so fast that the heart muscle cannot relax properly between contractions. This reduces the heart's efficiency and performance.


AF happens when abnormal electrical impulses suddenly start firing in the atria (top left and right chambers of the heart). These extra impulses override the heart's natural pacemaker call the SA node, which can then no longer control the rhythm of the heart. This causes you to have a highly irregular pulse rate.


Is AF dangerous?


The main risk of having AF is that it increases your risk of having a stroke. The reason for this is that when the heart rhythm is in AF, blood then pools in the top chamber of the heart (atria) as the top of the heart beats so fast. This pooled blood over time can then form a blood clot. A blood clot can then travel and lodge in the brain and cause a stroke. So the main risk is having a stroke and the problems that come with that.


As well as the risk of stroke, AF increases your risk of causing heart failure over the long term. The longer that your heart is in AF, the greater this risk is. This is because having a high pulse rate and especially if combined with high blood pressure, can cause the ventricles of the heart to enlarge and stretch. If the heart has to deal with this for a long period then heart failure can occur. AF that’s well controlled with medication lowers the risk of this happening.


What treatments are there for AF?


The different types of treatment for AF is usually decided after a discussion with your cardiologist to determine your risk factors, your symptoms and how AF is affecting your quality of life.


Whilst AF is not usually life threatening, it can be uncomfortable and often requires treatment.


Treatment may involve: 

  • Medication to prevent a stroke (people with atrial fibrillation are more at risk of having a stroke) - most people are prescribed NOAC’s - Rivaroxaban, Apixaban, Dabigitran. Warfarin is an older medication that used to be used, and sometimes is in certain cases.
  • Medication to control the heart rate or rhythm
  • Cardioversion – where the heart is given a controlled electric shock to restore normal rhythm - you are given medication to put you asleep so you don’t feel anything. 
  • Ablation – where the area inside the heart that's causing the abnormal heart rhythm is destroyed using radiofrequency energy - the extra electric cells can be removed via cold freezing or burning. 

Exercising with AF:

Many of my clients come to me because they are unsure and worried about exercising with Af. Whilst every client session and program is different and tailored to their fitness levels, goals and medical history, here are some of the broad exercise recommendations I give people who have AF:

  • Always include a longer than usual warm up - at least 10-15 minutes of gradually increasing the speed or intensity of the exercise.
  • Use the ‘talk test’ as a guide to how hard to work. You should be able to speak at least 6-7 words without having to take a breath. This means you’ll be able to workout for much longer.
  • Include exercises that use bigger muscle groups rather than smaller ones. Eg focus on exercises that work the back muscles, chest muscles and leg muscles rather than just the arms or tummy muscles. 
  • Avoid doing exercises that make you hold your breath. When you have AF and are exercising it’s important to ensure there’s enough blood flow and oxygen to the muscles, including the heart muscle! By holding your breath you’ll be restricting the blood and oxygen that’s available so avoid things that make you hold your breath.
  • Always include a cool down of at least 5-10 minutes and include a stretch! Cooling down gradually ensures that blood flow returns from the legs and other muscles back to the heart and doesn’t ‘pool’ in the legs. Avoid suddenly stopping - it’s like slamming on the brakes when you’re on the motorway!

Exercise with me


If you’d like to know more about exercising with me, visit my program page or get in touch HERE. I’d love to help you get back exercising again and feel confident and fit with AF.


Other resources:


Dr Warrick Bishop is a Cardiologist who has written several fantastic heart books, one of which is all about AF. Atrial Fibrillation Explained gives a great overview of AF and its treatment. Knowledge is power and knowledge can be the antidote to fear of the unknown. In plain language, Dr. Bishop explains how the heart works, what happens when AF occurs, and how it can lead to clot formation and stroke if left undetected and untreated. He then moves on to the various treatment options, illustrated with case histories. This book is a must-read for those with AF, and those who care about those with AF.


About Me

I'm Angela Hartley, Cardiac Nurse and Exercise Coach and I'm here to help you get fitter, stronger and get your mojo back. 

No matter how unfit you are or what heart condition you have, we can help! As part of the programmes on offer you will feel part of a community, be able to use a range of tools to keep you motivated and have access to a members area on the website where you can interact with others, learn more about your heart condition and track your progress.

Learn more about my Zoom classes here and my one-to-one programmes here.