Heart Explained

Arrhythmias

Atrial flutter

What is atrial flutter?

Atrial flutter is a common type of arrhythmia. It is similar to atrial fibrillation (AFib) but is generally considered to be less severe and less problematic for your health. 

As with AFib, the two upper chambers of the heart (the atria) contract too quickly, but in atrial flutter the heart’s rhythm is still regular; in AFib it is irregular and often chaotic.

A normal resting heart rate is 60 – 100 beats per minute but if you have atrial flutter it will typically be around 150 beats per minute.

Heart contractions: Atrial flutter vs normal

A heart with atrial flutter isn’t able to pump as efficiently as a normal heart and, in the long term, this may cause heart failure and other problems.

Atrial flutter can also raise your risk of having a stroke, because the fast, shallow atrial contractions allow blood to pool in the atria instead of completely emptying into the ventricles. This pooled blood can then clot, and if a blood clot breaks off and travels to your brain it can then cause a stroke.

If you want learn more about a normal heartbeat take a look at How your heart pumps.

Blood clot forming in a fluttering atrium

What causes atrial flutter?

The pumping mechanism of your heart is regulated by complex electrical signals. These signals control your heart’s rate and rhythm, and are, in turn, controlled by the heart’s sinoatrial (SA) node, which is in the right atrium.

With each heartbeat, the SA node fires an electrical pulse that spreads down through the heart to the atrioventricular (AV) node. The AV node then passes the signal on to the ventricles and this causes your heart to beat in an organized way.

When your heart’s rate and rhythm are disrupted, you have an arrhythmia.  To learn more about arrhythmias, check out our Arrhythmias section homepage.

Electrical signals: Atrial flutter vs normal heart

In atrial flutter, the SA node is no longer in full control of the electrical signaling and the pulses fire too rapidly – usually around 300 times per minute – causing very fast, fluttering atrial contractions.

The AV node blocks about half of these signals, so the ventricles, which do the heart’s real pumping work, will typically contract only once for every two atrial flutters. The result is a very rapid pulse rate of around 150 beats per minute.

Usually, atrial flutter is the result of some kind of heart damage or structural problem, which can have a wide range of causes, from heart failure to infections. Anything that enlarges or distorts the left atrium can result in atrial flutter.

Common causes of atrial flutter include:

To learn more about how your heart works, take a look at Your heart’s electrical system.

What are the symptoms of atrial flutter?

Some people with atrial flutter have no symptoms and may not know that anything is wrong.

When symptoms do occur, they can vary from person to person, but they usually include palpitations, tiredness, and shortness of breath.

Here’s a list of common symptoms of atrial flutter:

  • A fluttering feeling in the chest (palpitations)
  • A racing heartbeat
  • Shortness of breath
  • Dizziness
  • Chest discomfort
  • Extreme tiredness

How is atrial flutter treated?

Your doctor will determine the best course of treatment for your atrial flutter depending on its severity and the potential impact on your health.

First, you will probably be prescribed medications that will slow and control your heart rate, such as beta blockers, calcium channel blockers. or other anti-arrhythmic drugs.

Then, if you are at risk of having a stroke (especially if you have other disorders that raise that risk), you will also be prescribed a blood-thinning medication to prevent clots.

If necessary, your doctor may recommend resetting your heart’s rhythm using cardioversion, which involves delivering a small shock to your chest, or a catheter-based procedure called cardiac ablation, which involves deactivating the damaged tissue that is disrupting your heart’s normal electrical signaling.

Treatments for atrial flutter include:

  • Medications to control your heart rate
  • Blood-thinning medication to prevent clots and strokes
  • Cardioversion (a small shock to the chest that resets the heart’s rhythm)
  • Medications that help to maintain your heart’s normal rhythm
  • A catheter-based procedure called cardiac ablation (if medications and cardioversion don’t help)
  • Avoiding stimulants like caffeine and decongestants
  • Maintaining a healthy lifestyle to help control blood pressure, body weight, and stress levels

What are the aims of treatment?

The immediate aims of treatment for atrial flutter are to reset the rhythm of your heart and slow and control your heart rate.

The ultimate aim is to prevent damage to your heart, which could lead to heart failure, and lower your risk of having a stroke or heart attack.