Atrial flutter

What is atrial flutter?

Atrial flutter is a type of abnormal heart rhythm whereby the heart beats at an excessively high rate. Medically, a heart rate of over 100 beats per minute is known as tachycardia, which is why this condition is also known as a tachycardic arrhythmia.

With atrial flutter, the atria contracts at a frequency of around 250-450 beats per minute. This may lead to a gradual progression to atrial fibrillation, where rates of up to 600 beats per minute can be reached.

How does atrial flutter develop?

Atrial flutter is caused by reentrant circuits in the atrium. This means that the excitation is not only transmitted along the heart's natural conduction system but also affects other areas of the atrium. A typical atrial flutter involves the cells around the right heart valve (tricuspid valve), while atypical atrial flutter usually involves an area near the left heart valve (mitral valve).

The cardiac conduction system is vital for a healthy heart rhythm. The excitation is generated in the sinus node located in the right atrium and is then continuously transmitted from the atria to the ventricles via the AV node. As a result, the ventricles contract in a set rhythm and eject blood into the systemic and pulmonary circulation.

If the atrium beats too quickly, it can also lead to an excessively high frequency of ventricular contractions. When these contract too quickly, they cannot be sufficiently filled with blood and as a result cannot adequately supply the circulation with oxygen.

With atrial flutter, the ventricles do not typically receive every excitation, and the AV node acts as a kind of filter. The ventricles generally contract at a rate of around 140 beats per minute.

Triggers and risk factors

Atrial flutter mainly affects patients with pre-existing heart conditions. Risk factors include coronary artery disease (CAD), rheumatic heart valve disease, high blood pressure, or cardiomyopathies, which impair the functionality of the heart muscle. Although less common, atrial flutter can also result from thyroid disease, embolism, or inflammatory heart disease.

In some cases, atrial flutter can occur in otherwise heart-healthy patients. Typical triggers in these situations include emotional stress, excessive alcohol consumption, or heavy coffee consumption.

Symptoms of atrial flutter

How severe the symptoms of atrial flutter are depend on how the excitation is transferred from the atrium to the ventricles via the AV node. For example, if only every second or third excitation is transmitted, then the patients usually have stable circulation, and the arrhythmia is well tolerated.

However, in the case of a 1:1 conduction, each atrial excitation is transmitted to the ventricles causing them to contract at very high frequencies. This can lead to ventricular tachycardia or ventricular fibrillation, which are cardiac arrhythmias that can lead to potentially fatal shock and must be treated as quickly as possible.

How is atrial flutter diagnosed? 

If atrial flutter occurs intermittently, a detailed medical history and physical examination are carried out first. Questions about any pre-existing illnesses are particularly important. Then, an ECG, or electrocardiogram, is performed to record the electrical activity of the heart and thereby allow important conclusions about the heart rhythm and function to be drawn.

The ECG can show characteristic changes during an acute episode, allowing a diagnosis to be made. However, the resting ECG during a symptom-free period often does not display any specific changes. In such cases, a 24-hour Holter monitor, or an echocardiogram might be performed. The latter is an ultrasound examination of the heart.

An electrophysiological examination of the heart can be carried out to localize the origin of the underlying circular excitation in the atrium. A specialized catheter is introduced to the heart through a vessel and an ECG is performed directly on the heart. Additionally, electrical impulses can be delivered to identify the area of the reentrant circuit.

What treatment options are there?

In the treatment of atrial flutter, we differentiate between symptomatic treatment options, which are mainly used in acute cases, and curative treatment methods.

To treat patients with severe symptoms and an unstable circulation, cardioversion is initially performed. An electric shock is administered with the goal of resynchronizing the activity of the heart muscle cells and restoring the normal heart rhythm. If necessary, repeated stimulation of the atria through a catheter may also be beneficial.

In many patients, these measures initially result in atrial fibrillation, which then transitions to a normal heart rhythm within a few hours.

In patients with less pronounced symptoms, it may not be necessary to perform cardioversion but instead to administer various medications to stabilize the heart rhythm.

The application of different medications can also be used for long-term therapy. However, the focus should be on treating any underlying disease.

A curative approach consists of catheter ablation. In this procedure, a catheter is inserted up to the heart, and the areas in which circling excitation arises are ablated. This is usually done immediately after an electrophysiological examination of the heart. The catheter ablation has a success rate of over 95%.

Prognosis and life expectancy

Atrial flutter can lead to potentially life-threatening arrhythmias such as ventricular tachycardia or ventricular fibrillation. Fortunately, these complications occur in only very few cases. The prognosis for atrial flutter therefore largely depends on the type of underlying condition.

Which doctors and clinics specialize in atrial flutter?

In an acute case, the treatment of atrial flutter falls within the field of emergency medicine, because therapy should be started as soon as possible. Specialists in internal medicine and cardiology specialize in detailed diagnosis and treatment.

We have made it our goal to bring patients and expert specialists together. Therefore, all doctors listed here have been carefully selected for their expertise in the medical field of cardiology. All of them have extensive experience in the treatment of atrial flutter and are ready for your treatment requests.