Atrial flutter and atrial fibrillation are two closely related heart rhythm disorders. They can coexist in the same individual, with one or the other appearing at different times over the course of life.

Although it would be possible to group them into a single text because of their similarities, they are presented separately to allow a clearer understanding of their specific mechanisms, clinical features, and treatment options.

Often rapid heartbeats

Atrial flutter is an arrhythmia characterized by a generally rapid and regular heart rhythm.

The heart rate may exceed 150 beats per minute, which explains the frequent perception of palpitations.

An arrhythmia originating in the atria

Like atrial fibrillation, atrial flutter originates in the atria, the upper chambers of the heart.

An overexcited new conductor

In atrial flutter, the heart’s usual electrical conductor is replaced by an abnormal electrical circuit, responsible for this excessive atrial activity.

Fortunately, the electrical conduction system between the atria and the ventricles acts as a filter: only one impulse out of two is transmitted to the ventricles. This results in a pulse often close to 150 beats per minute.

Thus, as in atrial fibrillation, the heart rate is rapid. However, unlike atrial fibrillation, the pulse most often remains regular.

The heart rate may be slower when the conduction system is already impaired or under the effect of medications intended to slow the heart.

Risk of blood clot formation in the heart

The main risk associated with atrial flutter is the formation of blood clots that can enter the circulation.

When the atria beat at a very high rate, around 300 beats per minute, their contraction becomes ineffective. Blood then tends to pool within the atria, which promotes clot formation, a phenomenon also seen in atrial fibrillation.

The major danger is that a clot can break loose and be carried into the systemic circulation, causing a systemic embolism. If a fragment travels to the brain, it can lead to a stroke, the consequences of which may be severe and sometimes permanent.

A generally benign arrhythmia

Despite the possible risk of blood clot formation, atrial flutter is generally considered a benign arrhythmia, especially when it is well managed and appropriately monitored.

IT IS POSSIBLE TO LIVE VERY WELL WITH ATRIAL FLUTTER

Absence of symptoms or variable palpitations

In some individuals, atrial flutter may be completely asymptomatic, with no perception of palpitations.
Others experience rapid and uncomfortable heartbeats, sometimes causing anxiety.

Some people instead report:

  • unusual fatigue,
  • a reduced ability to perform physical activity,
  • shortness of breath, particularly during exertion.

 

The intensity of symptoms therefore varies greatly from one person to another.

Possible causes of atrial flutter

The prevalence of atrial flutter increases with age, which explains why it is more commonly observed in older adults. Depending on the populations studied, it may affect approximately 5 to 10% of individuals.

Certain medical conditions are more frequently associated with its occurrence, including:

  • hypertension,
  • diabetes,
  • heart failure.

As with atrial fibrillation, other diseases or situations may also promote this rhythm disorder, such as:

  • vascular conditions,
  • diseases of the heart muscle or the coronary arteries,
  • inflammation of the lining of the heart (pericarditis), particularly after cardiac or thoracic surgery,
  • certain lung diseases, such as chronic obstructive pulmonary disease (COPD) or pulmonary embolism,
  • thyroid disorders, especially hyperthyroidism.

 

In some cases, however, no specific cause can be identified. This is referred to as idiopathic atrial flutter.

Two strategies for treating atrial flutter

Treatment of atrial flutter generally relies on two complementary goals:

  1. Treat the heart rhythm
  2. Reduce the risk of blood clot formation

(1) Treating the heart rhythm

Management of atrial flutter may follow two main approaches:

  • controlling the heart rate by slowing the heart;
  • controlling the rhythm by stopping the arrhythmia and restoring a normal rhythm, known as sinus rhythm.

 

Numerous medical studies have compared these two strategies. Overall, they show that both approaches are equivalent, with no clear advantage of one over the other. The choice therefore depends on the clinical context, the presence of symptoms, and preferences discussed with the physician.

1️⃣ Slowing the heart

In the absence of significant symptoms, it is often simpler to control the heart rate. This approach is frequently chosen as a first-line strategy.

In some cases, however, medications used to slow the heart may reduce the heart rate excessively. The cardiologist may then discuss the possibility of implanting a permanent pacemaker.
The pacemaker acts as an electrical safety net, preventing the heart rate from dropping below a predetermined threshold.

2️⃣ Stopping the arrhythmia

When slowing the heart is not sufficient to relieve symptoms, or when the arrhythmia remains poorly tolerated, other options may be considered.

A) Medication

Even when the heart rate is adequately controlled, the persistence of an abnormal rhythm may cause discomfort and interfere with daily activities.

The physician may then prescribe oral medication to correct the heart rhythm and restore regularity.

B) Electrical cardioversion

If medication is ineffective or poorly tolerated, another option is electrical cardioversion.

This procedure aims to stop the arrhythmia by delivering an electrical shock to the chest, allowing the heart to return to a normal rhythm.

Contrary to what is sometimes portrayed on television, cardioversion is performed in a controlled medical setting. It requires short-acting sedation: the person is asleep for only a few minutes. Once the shock is delivered and the rhythm restored, awakening occurs gradually.

Like any medical procedure, cardioversion carries certain risks. These are always evaluated and explained, and this option is chosen when the expected benefits outweigh the risks.

C) Ablation: treating the arrhythmia at its source

In some cases, the cardiologist may recommend catheter ablation, sometimes from the first evaluation or after failure of previous treatments, especially in highly symptomatic individuals.

During this procedure, the area within the atria responsible for atrial flutter is precisely identified and then neutralized using:

  • radiofrequency energy (heat), or
  • cryotherapy (cold).

 

This intervention often results in a long-lasting elimination of the arrhythmia.

To read: Ablation of an arrhythmia

(2) Reducing the risk of blood clot formation

The role of an anticoagulant is not to “thin the blood,” but rather to reduce the risk of blood clots forming in the heart and to prevent them from traveling through the bloodstream.

The decision to prescribe an anticoagulant is based on an individualized assessment. The physician considers several factors, including:

  • age,
  • the presence of diabetes or high blood pressure,
  • a history of stroke,
  • the presence of heart failure.

 

Once this type of treatment is started, it is often required long term, sometimes even indefinitely.
At each step, the physician carefully balances the risk of embolization (formation and migration of a clot) against the risk of bleeding, in order to choose the safest strategy.

Never stop anticoagulant medication without medical advice

Anticoagulant therapy should never be stopped on one’s own initiative.

Any change or interruption must be discussed with the physician, as inappropriate discontinuation may expose the individual to a significantly increased risk of serious complications, including stroke.

ANTICOAGULANTS ARE NOT INTENDED TO THIN THE BLOOD, BUT TO PREVENT THE FORMATION OF BLOOD CLOTS.

Conclusion

Atrial flutter is a common heart rhythm disorder that is generally benign, but it requires appropriate management because of the potential risk of blood clot formation and stroke.
Its clinical presentation varies widely: some individuals experience no symptoms, while others may be troubled by palpitations, fatigue, or shortness of breath.

Treatment is based on two complementary approaches: controlling the heart rhythm and preventing blood clots, using strategies tailored to each situation. With medication, cardioversion, and, in some cases, catheter ablation, it is now possible to effectively control this arrhythmia and maintain a good quality of life.

Regular medical follow-up remains essential to adjust treatment, prevent complications, and ensure safe long-term management.