Atrial flutter and atrial fibrillation (AFib) are both types of arrhythmias. They both occur when there are problems with the electrical signals in the heart. Atrial flutter and AFib are similar yet distinct conditions.

Both conditions are caused by issues with the electrical signals that make your heart chambers contract. When your heart beats, you’re feeling these chambers contracting. Atrial flutter and AFib are both caused when the electrical signals occur faster than normal. The biggest difference between the two conditions is in how this electrical activity is organized.

People with AFib or atrial flutter may not experience any symptoms. If symptoms do occur, they are similar:

SymptomAtrial fibrillationAtrial flutter
rapid pulse rate usually rapid usually rapid
irregular pulse always irregularcan be regular or irregular
dizziness or faintingyesyes
palpitations (feeling like the heart is racing or pounding)yesyes
shortness of breathyesyes
weakness or fatigueyesyes
chest pain or tightnessyesyes
increased risk of blood clots and strokeyesyes

The major difference in symptoms is in the regularity of the pulse rate. Overall, the symptoms of atrial flutter tend to be less severe. There is also less risk of clot formation and stroke.

AFib

In AFib, the two top chambers of your heart (atria) receive chaotic electrical signals. The atria beat out of coordination with the bottom two chambers of your heart (ventricles). This leads to a rapid and irregular heart rhythm. A normal heart rate is 60 to 100 beats per minute (bpm). In AFib, the heart rate ranges from 100 to 175 bpm.

Atrial flutter

In atrial flutter, your atria receive organized electrical signals, but the signals are faster than normal. The atria beat more frequently than the ventricles (up to 300 bpm). Only every second beat gets through to the ventricles. The resulting pulse rate is around 150 bpm. Atrial flutter creates a very distinct “sawtooth” pattern on a diagnostic test know as an electrocardiogram (EKG).

Keep reading: How your heart works »

Risk factors for atrial flutter and AFib are very similar:

Risk factorAFibAtrial flutter
previous heart attacks
high blood pressure (hypertension)
heart disease
heart failure
abnormal heart valves
birth defects
chronic lung disease
recent heart surgery
serious infections
abuse of alcohol or drugs
overactive thyroid
sleep apnea
diabetes

People with a history of atrial flutter also have an increased risk of developing atrial fibrillation in the future.

Treatment for AFib and atrial flutter has the same goals: to restore the normal rhythm of the heart and prevent blood clots. Treatment for both conditions may involve:

Medications:

  • calcium channel blockers and beta-blockers to regulate the heart rate
  • amiodarone, propafenone, and flecainide to convert the rhythm back to a normal
  • blood-thinning medications such as warfarin (Coumadin) to prevent stroke or heart attack

Electrical cardioversion: This procedure uses an electrical shock that resets the rhythm of your heart.

Catheter ablation: Catheter ablation uses radiofrequency energy to destroy the area inside your heart that’s causing the abnormal heart rhythm.

Atrioventricular (AV) node ablation: This procedure uses radio waves to destroy the AV node. The AV node connects the atria and ventricles. After this type of ablation, you’ll need a pacemaker to maintain a regular rhythm.

Maze surgery: Maze surgery is an open-heart surgery during which the surgeon makes small cuts or burns in the heart’s atria.

According to the British Heart Foundation, medication is usually the first treatment for AFib. On the other hand, ablation is usually considered the best treatment for atrial flutter. In fact, catheter ablation is successful in up to 90 percent of people with atrial flutter. Still, ablation therapy is typically only used when medications can’t control the conditions.

Both AFib and atrial flutter involve faster than usual electrical impulses in the heart. But there are a few main differences between the two conditions.

Main differences

  • In atrial flutter, the electrical impulses are organized. In AFib, the electrical impulses are chaotic.
  • AFib is more common than atrial flutter.
  • Ablation therapy is more successful in people with atrial flutter.
  • In atrial flutter, there is a "sawtooth" pattern on an ECG. In AFib, the ECG test shows an irregular ventricular rate.
  • The symptoms of atrial flutter tend to be less severe than the symptoms of AFib.
  • People with atrial flutter have a tendency to develop AFib, even after treatment.

Both conditions carry an increased risk of stroke. So whether you have AFib or atrial flutter, it is important to get a diagnosis early so you can get the right treatment.