What is atrial flutter?

The terms “atrial fibrillation” and “atrial flutter” are often used almost interchangeably, and even within the medical profession there is some haziness about where one problem stops and the other starts. The difference between these two diagnoses is important, however, because symptoms, prognosis and treatment options differ considerably between these two distinct rhythm problems.


A lot of the misunderstanding in this area arises because the term “flutter” tends to be used rather imprecisely by both patients and doctors. I meet quite a lot of patients, for example, who describe the feeling they get in their chest as a “flutter”. There is of course nothing wrong with using this word! If you feel you have a “flutter in your chest” then no-one - least of all me - is in a position to tell you that you are wrong. Where things become confusing is when your doctor then uses your terminology about the symptom you feel to describe the mechanism of the arrhythmia (the so-called “pathophysiology”).


From a pathophysiological perspective, the word “flutter” should only be used to describe an arrhythmia mechanism in strictly defined circumstances. To be called a “flutter”, an abnormal heart rhythm should be fast, sustained, and caused by a continuous repetitive racing of electricity around a single electrical short circuit within a single heart chamber. The most common setup where this happens is referred to as “typical atrial flutter”.


Typical atrial flutter arises due to an anatomical and electrical feature that is present in the right atrium of almost every human heart; thus this form of “flutter” is in the same place and at the same speed and causes similar symptoms in most people who suffer from it. Typical atrial flutter tends to cause the atria (upper chambers) to race at around 300bpm in a way that is that it is self-perpetuating: once electricity has gone around the flutter circuit once, it will do it again and again with no real reason why it should ever stop. This can lead to problems such as a persistently elevated heart rate, breathlessness, lack of response in the heart rate to exercise, and - if it goes on long enough - eventual fatigue and failure of the lower chambers of the heart.


The good news about typical atrial flutter is that because it is caused by the same part of the heart in everyone who gets it, we’ve got pretty good at recognizing this arrhythmia from the pattern it makes on an ECG, and we’ve also got pretty good at curing it. The cure is an ablation procedure to cauterise the part of the heart that is responsible. The chance of lasting success from an ablation for typical atrial flutter is somewhere approaching 98%; i.e. out of every 100 patients undergoing this procedure, on average only two or so will ever have this problem again. This is quite a different prospect from a lot of other ablation procedures, and in particular very different from the situation with atrial fibrillation, for example.


There is undoubtedly a relationship between atrial flutter and atrial fibrillation; around 40% of patients initially diagnosed with atrial flutter will go on to be diagnosed with atrial fibrillation at a later date. However, despite occurring in the same patients, and having common causes, these two rhythms have extensive differences.

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You can read more about atrial fibrillation and other cardiac problems on the patient information pages of my private practice website at https://www.kentlondoncardio.com.

Location: Ashford, UK

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