Atrial Flutter

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Atrial flutter is a cardiac arrhythmia that is related in many ways to atrial fibrillation. Atrial flutter is characterized by extremely rapid electrical impulses arising in the atria, leading to an overall heart rate that is usually about half the atrial rate. In atrial flutter, the atrial rate is most often around 300 beats per minute, and the ventricular rate is around 150 beats per minute. Because this arrhythmia originates in the atria, it is considered a form of supraventricular tachycardia.

What Is Atrial Flutter?

Atrial flutter is a type of reentrant arrhythmia; it occurs when an electrical impulse becomes “trapped” in a circuit within the heart, and begins spinning around and around that circuit. With atrial flutter, the reentrant circuit is a relatively large one that is usually located within the right atrium, and which usually follows a characteristic path.

This fact often makes atrial flutter particularly suitable for ablation therapy. By creating a blockage in a particular location within that characteristic path, the reentrant circuit can be disrupted, and the atrial flutter can no longer occur.

What Are The Symptoms of Atrial Flutter?

The rapid heart rate commonly produce by atrial flutter most often leads to pronounced palpitations, dizziness, fatigue, and dyspnea (breathlessness). Like most reentrant arrhythmias, episodes of atrial flutter tend to come and go quite suddenly and unexpectedly.

If a patient with atrial flutter also has coronary artery disease, the rapid heart rate can place enough stress on the cardiac muscle to cause angina. Atrial flutter can also produce a sudden worsening of symptoms in people who have heart failure.

Why Is Atrial Flutter Important?

Because the symptoms it produces can be intolerable, atrial flutter would be a significant arrhythmia even if all it did was cause palpitations, dizziness and dyspnea.

But the biggest problem related to atrial flutter is that, as is the case with atrial fibrillation, this arrhythmia tends to cause thrombus formation (blood clots) in the atria. These blood clots can break loose (embolize) and cause strokes. So people with atrial flutter, like those with atrial fibrillation, have a significantly increased risk of stroke.

Furthermore, atrial flutter often tends to be a “bridge arrhythmia” to atrial fibrillation. That is, people with atrial flutter will often go on to develop chronic atrial fibrillation.

Who Gets Atrial Flutter?

While anyone can develop atrial flutter, it is not a common arrhythmia. It is much less frequent, for instance, than atrial fibrillation.

The people most likely to develop atrial flutter are the same ones also most likely to develop atrial fibrillation. These include people who are obese, or who have lung disease (including pulmonary embolus), sleep apnea, sick sinus syndrome, pericarditis, or hyperthyroidism. Atrial flutter is also seen in people who have had recent heart surgery.

How Is Atrial Flutter Diagnosed?

Diagnosing atrial flutter is fairly straightforward. It merely requires capturing the arrhythmia on an ECG, and looking for what are called “flutter waves.” Flutter waves are signals appearing on the ECG that represent the electrical impulse that is spinning around and around the atrial reentrant circuit.

How Is Atrial Flutter Treated?

With one major exception, the treatment of atrial flutter is similar to that of atrial fibrillation. That one exception is that, in comparison to atrial fibrillation, using ablation therapy to eliminate atrial flutter is relatively easy to accomplish.

Acute Episodes.

In patients who are having an acute episode, atrial flutter can be stopped quite readily with electrical cardioversion, or by acutely administering antiarrhythmic drugs (usually, ibutilide or dofetilide).

If symptoms are severe during an acute episode, slowing the heart rate may be necessary while making preparations for cardioversion. This can often be accomplished quickly by administering intravenous doses of the calcium blockers diltiazem or verapamil, or the rapidly-acting intravenous beta blocker esmolol. These drugs must be used cautiously, however, in patients with heart failure.

Long-term Treatment.

Once an acute episode has been dealt with, the next step is to attempt to suppress further episodes of atrial flutter. In this regard it is important to look for, and treat, any reversible underlying cause, such as hyperthyroidism, sleep apnea, or obesity. Hyperthyroidism can usually be sufficiently controlled within a few days, and sleep apnea is also generally treatable within in a reasonable period of time. While obesity is also a reversible cause of atrial flutter, in practical terms it is often not reversed sufficiently or quickly enough to benefit the treatment of this arrhythmia - so other means of controlling it must be used.

If no readily reversible cause is found, chronic antiarrhythmic treatment is necessary. The chronic treatment of atrial flutter generally consists either of suppressing the arrhythmia with drugs, or using ablation therapy.

Antiarrhythmic drugs have a poor success rate with atrial flutter - only 20% to 30% of patients treated with drugs are successfully controlled after a year of therapy. For this reason, and because of the many toxicities common with antiarrhythmic drug therapy, ablation therapy is by far the treatment of choice for atrial flutter.

Fortunately, as noted earlier, the ablation of atrial flutter is usually a relatively straightforward procedure, with a very favorable rate of success - well over 90%. In the large majority of patients with this arrhythmia, ablation ought to be strongly considered.

Since ablation works so well, resorting to a “rate-control strategy” (commonly used for atrial fibrillation) is only rarely necessary for atrial flutter. A rate control strategy means allowing the arrhythmia to occur, and controlling the resulting heart rate, to minimize symptoms.

Controlling the heart rate in atrial flutter is substantially more difficult than it is with atrial fibrillation, and commonly requires the use of a combination of beta blockers and calcium blockers. On occasion, to get the heart rate under control it is necessary to ablate the heart’s normal conducting system to create heart block, then insert a pacemaker to establish a stable heart rate. Obviously, getting rid of the atrial flutter altogether with an ablation procedure is usually the far more preferable course of action.

In cases where a rate-control strategy is used, however, chronic anticoagulation therapy is recommended to prevent stroke, just as it is with atrial fibrillation.


Wellens HJ. Contemporary management of atrial flutter. Circulation 2002; 106:649.

Granada J, Uribe W, Chyou PH, et al. Incidence and predictors of atrial flutter in the general population. J Am Coll Cardiol 2000; 36:2242.

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