Atrial flutter

Atrial flutter
Synonyms	AFL
Pronounce
Field	Cardiology
Symptoms	Palpitations, shortness of breath, dizziness, fatigue, chest pain
Complications	Stroke, heart failure, cardiomyopathy
Onset	Sudden
Duration	May be intermittent or persistent
Types	Typical (counterclockwise or clockwise), Atypical (non-cavotricuspid isthmus dependent)
Causes	Heart disease, hypertension, valvular heart disease, pulmonary embolism, hyperthyroidism, post-cardiac surgery
Risks	Advancing age, hypertension, diabetes, coronary artery disease, heart failure, previous atrial fibrillation
Diagnosis	ECG, Holter monitor, electrophysiology study
Differential diagnosis	Atrial fibrillation, supraventricular tachycardia, sinus tachycardia
Prevention	Control of underlying conditions, anticoagulation to reduce stroke risk
Treatment	Electrical cardioversion, catheter ablation, rate control
Medication	Beta blockers, calcium channel blockers, amiodarone, anticoagulants
Prognosis	Good with treatment; risk of recurrence without ablation
Frequency	Common; more prevalent in older adults and individuals with heart disease
Deaths	Rare with appropriate management; stroke can be fatal

Atrial flutter with a two to one block. Note the P waves hiding in the T waves in leads V1 and V2

Type I atrial flutter, counterclockwise rotation with 3:1 and 4:1 AV nodal block.

Atrial flutter is a type of abnormal heart rhythm or arrhythmia that originates in the atria of the heart. It is characterized by a rapid, regular heartbeat and is often associated with atrial fibrillation, another common type of arrhythmia. Atrial flutter can lead to significant symptoms and complications if not properly managed.

Pathophysiology

Atrial flutter occurs when there is a reentrant circuit within the right atrium. This circuit causes the atria to contract at a rapid rate, typically around 240 to 340 beats per minute. However, due to the refractory period of the atrioventricular node, not all of these impulses are conducted to the ventricles, resulting in a ventricular rate that is often slower, commonly around 150 beats per minute.

The reentrant circuit in atrial flutter is usually a macro-reentrant circuit, which means it involves a large loop of electrical activity. This is in contrast to atrial fibrillation, where the electrical activity is more chaotic and disorganized.

Symptoms

Patients with atrial flutter may experience a variety of symptoms, including:

• Palpitations
• Shortness of breath
• Fatigue
• Dizziness or lightheadedness
• Chest pain

In some cases, atrial flutter may be asymptomatic and only discovered during a routine electrocardiogram (ECG).

Diagnosis

The diagnosis of atrial flutter is typically made using an electrocardiogram (ECG). The ECG will show a characteristic "sawtooth" pattern of atrial activity, known as "F-waves," particularly in the inferior leads (II, III, and aVF). The ventricular rate is often regular and can be a multiple of the atrial rate, commonly 2:1 conduction.

Treatment

The treatment of atrial flutter aims to control the heart rate, restore normal rhythm, and prevent complications such as stroke. Treatment options include:

• Rate control: Medications such as beta-blockers or calcium channel blockers can be used to slow the ventricular rate.
• Rhythm control: Cardioversion can be performed to restore normal sinus rhythm. This can be done electrically or with medications such as ibutilide.
• Catheter ablation: This procedure involves destroying the reentrant circuit in the right atrium using radiofrequency energy, which can provide a long-term solution to atrial flutter.
• Anticoagulation: Patients with atrial flutter are at increased risk of thromboembolism, and anticoagulation therapy may be necessary to reduce the risk of stroke.

Prognosis

The prognosis for patients with atrial flutter varies depending on the underlying cause and the presence of other medical conditions. With appropriate treatment, many patients can achieve good control of their symptoms and reduce the risk of complications.

Related pages

• Atrial fibrillation
• Arrhythmia
• Electrocardiogram
• Cardioversion
• Catheter ablation