From the Guidelines
Atrial flutter and atrial fibrillation (AFib) are two distinct types of supraventricular tachyarrhythmias, with atrial flutter characterized by a regular, rapid atrial rhythm and atrial fibrillation marked by an irregular, rapid atrial rhythm.
Key Differences
- Atrial flutter typically has a regular atrial rate of 250-350 beats per minute, with a fixed block, usually 2:1 or 4:1, resulting in a ventricular rate of 125-175 beats per minute 1.
- Atrial fibrillation, on the other hand, is characterized by an irregular, rapid atrial rhythm, often exceeding 350 beats per minute, with an irregular ventricular response 1.
Diagnosis and Management
- The diagnosis of atrial flutter and AFib can be made using electrocardiogram (ECG), which shows a saw-tooth pattern of regular atrial activation in atrial flutter and irregular atrial activity in AFib 1.
- For acute management, patients with atrial flutter or fibrillation should be assessed for hemodynamic stability. If unstable, immediate cardioversion is recommended. For stable patients, rate control can be achieved with beta blockers, such as metoprolol, or calcium channel blockers, like diltiazem 1.
- Anticoagulation with medications like apixaban or rivaroxaban is crucial for stroke prevention in patients with AFib, and may be considered for those with atrial flutter, depending on individual risk factors 1.
Treatment Options
- Rhythm control can be achieved with anti-arrhythmic medications like flecainide or propafenone, but is not always necessary and may have side effects 1.
- Catheter ablation is a treatment option for patients with recurrent, symptomatic episodes of atrial flutter or AFib, and can be effective in preventing recurrent episodes 1. Some key points to consider when managing atrial flutter and AFib include:
- Prioritizing rate control over rhythm control, especially in patients with a first episode of atrial fibrillation or flutter 1.
- Considering catheter ablation for patients with recurrent, symptomatic episodes 1.
- Assessing individual risk factors for stroke and considering anticoagulation therapy accordingly 1.
From the FDA Drug Label
Ventricular Pro-arrhythmic Effects in Patients with Atrial Fibrillation/Flutter A review of the world literature revealed reports of 568 patients treated with oral flecainide acetate for paroxysmal atrial fibrillation/flutter (PAF). FLECAINIDE IS NOT RECOMMENDED FOR USE IN PATIENTS WITH CHRONIC ATRIAL FIBRILLATION. As with other Class I agents, patients treated with flecainide acetate for atrial flutter have been reported with 1:1 atrioventricular conduction due to slowing the atrial rate. A paradoxical increase in the ventricular rate also may occur in patients with atrial fibrillation who receive flecainide acetate
The main difference between atrial flutter and atrial fibrillation (AFib) mentioned in the label is the response to flecainide acetate treatment.
- Atrial flutter patients may experience 1:1 atrioventricular conduction due to slowing the atrial rate.
- Atrial fibrillation patients may experience a paradoxical increase in the ventricular rate when treated with flecainide acetate. Additionally, flecainide is not recommended for use in patients with chronic atrial fibrillation due to the risk of ventricular pro-arrhythmic effects 2.
From the Research
Differences between Atrial Flutter and Atrial Fibrillation
- Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in adults, with lifetime rates of 21% to 33% 3
- Atrial flutter (AFL) is the second most common sustained supraventricular arrhythmia 3
- Patients with AFL are at risk of developing AF, and many recommendations for managing AFL are similar to those for AF 3
- The preferred management for AFL is catheter ablation, with success rates exceeding 90% 3
- Treatment options for stable AF patients include scheduled cardioversion, rhythm control with pharmacotherapy, catheter ablation, and rate control with pharmacotherapy 3
Risk Factors and Complications
- Risk factors for AF include older age, hypertension, coronary disease, obstructive sleep apnea, diabetes, and others 3
- Patients with AF are at risk of developing complications such as hemodynamic instability, stroke, and thromboembolism 3, 4
- Atrial flutter and AF can be complications in approximately 30% of cases of paroxysmal supraventricular tachycardia (PSVT)-indicated catheter ablation 4
- Advanced age and frequent premature atrial contractions (PACs) are risk factors for PAC runs and/or atrial flutter and AF 4
Diagnosis and Management
- The electrocardiographic characteristics of supraventricular arrhythmias can have subtle but important clues to the diagnosis and initial management 5
- An understanding of the mechanisms of these arrhythmias is essential to provide proper therapy to the patient 5
- Drug therapy is the mainstay treatment for supraventricular tachyarrhythmias, including atrial flutter and atrial fibrillation 6
- Catheter ablation is increasingly used as first-line therapy for AF, with up to 80% of patients remaining AF-free after one or two ablation treatments 3