What is Atrial Fibrillation? (AF or AFib)
Atrial Fibrillation is a condition that creates a fast and irregular heart beat.
Atrial Fibrillation is a common heart arrhythmia – a condition where the heart beat is out of rhythm.
The normal heart beat occurs as coordinated electrical activity flows through the heart muscle, from the top chambers of the heart (the atria) to the bottom chambers (the ventricles). This creates a regular heart rate for an adult between 60-100 beats per minute at rest.
But during Atrial Fibrillation, the top chambers of the heart (the atria) don’t beat in their normal rhythm – the electrical activity that coordinates them becomes disorganised and chaotic. The atria start to beat in very a fast, quivery rhythm which can be in excess of 300 beats per minute.
The ventricles of the heart then receive a disorganised, uneven flow of activity. They beat fast, and irregularly, which is often measured at around 100-200 beats per minute.
But Atrial Fibrillation is not just the rhythm.
It’s a common misconception that you only have Atrial Fibrillation while the irregular rhythm is occurring – however, that is not the case.
Atrial Fibrillation is a chronic, long-term condition, in which there are changes to the tissues of the heart and the way they conduct electrical signals. These underlying changes can cause the rhythm episodes, and they are also a factor in an increased risk of stroke.
Due to aging, genetics, lifestyle and other risk factors, these changes in the heart’s electrical system occur over time. If left without treatment, then both the underlying changes and the episodes of the AF rhythm will progressively get worse.
Learn about the Heart's Rhythm and Atrial Fibrillation with Dr John Hayes
In this video, Dr John Hayes discusses his passion for Cardiac Electrophysiology, how the electrical signals of the heart cells create a heart beat, and how this changes in Atrial Fibrillation.
Does Atrial Fibrillation get worse over time?
Atrial Fibrillation is a long term condition – it is something that you will live with throughout your life and depending on a number of factors, it will usually gradually get worse. Without treatment, the natural progression of Atrial Fibrillation happens in three stages: from paroxysmal, to persistent to permanent.
These three stages of AFib describe the gradual progress of the condition, in which the AFib episodes become more frequent, last longer, and it becomes more difficult to return to normal rhythm.
Early in the condition, the episodes of AF rhythm will come and go on their own. The AF may last for seconds, minutes, hours or days, then the heart will return to its normal rhythm.
You may find that specific strategies or techniques assist quite well during this stage.
As your heart goes in and out of AF, you may feel your pulse rate changing from slow to fast and back again. People during this stage of AF are often more symptomatic – the individual episodes can be quite pronounced.
You may be prescribed medications to reduce the chance of the AF rhythm episodes occurring. Recent evidence also suggests that ablation procedures can be most effective before AFib becomes persistent.
Over time, your AF episodes may start to last longer, and be more difficult to reset back to sinus rhythm. When the episodes are tending to last for 7 days or more, and are more difficult to reset, this is referred to as ‘Persistent Atrial Fibrillation’.
Simple strategies at home may not work as well. During Persistent AF, medications are often needed to return to normal rhythm, or a Cardioversion at the hospital, where an electrical shock is given to reset the heart rhythm.
You may also find that even after a re-set, the AF episodes may return more frequently.
During this stage, the treatment strategies are still focussed on resetting the AF rhythm back to normal, and may include medications or one or more ablations.
Once it becomes too difficult to reset the heart back to sinus rhythm despite best efforts, you may reach the stage of Permanent AF.
During this stage, your treatment no longer attempts to reset the rhythm, instead, your treatment focusses on controlling your heart rate back to a more manageable speed. There are different medications and procedures in this stage that focus on reducing discomfort and the exertion on the heart over time.
How Common is Atrial Fibrillation?
AFib is one of the most common heart conditions. While other heart disease may be relatively declining due to awareness and health programs, AFib is increasing.
- Around 2% of Australians have AFib -that’s around 600 000 Australians.
- There are over 37.5 million people worldwide with AFib.
As you get older:
- You are more likely to be diagnosed with AFib
- It will become more common in people your age.
- By age 85, almost one in five people have AFib.