Atrial Flutter on ECG

Introduction

Atrial flutter is a common type of heart arrhythmia characterized by rapid and regular atrial contractions. It is often seen on an electrocardiogram (ECG) and can have significant implications for heart function and stroke risk.

Understanding Atrial Flutter

1. What Happens in the Heart?

• The heart has a natural pacemaker (the sinus node) that regulates the heartbeat.
• In atrial flutter, abnormal electrical circuits form in the atria (the upper chambers of the heart), leading to rapid contractions (250-350 beats per minute).
• The ventricular response is usually slower due to the filtering effect of the atrioventricular (AV) node.

2. ECG Characteristics of Atrial Flutter

• Regular atrial activity at a rate of ~250-350 bpm
• Characteristic “sawtooth” pattern of flutter waves (F-waves) best seen in leads II, III, and aVF
• Fixed or variable AV block, meaning not every atrial impulse conducts to the ventricles
• Narrow QRS complexes, unless there is an additional conduction abnormality

Causes and Risk Factors

Atrial flutter is often associated with: - Structural heart diseases (e.g., coronary artery disease, heart failure, valve disorders) - Hypertension (high blood pressure) - Chronic lung disease and pulmonary embolism - Excessive alcohol consumption (sometimes called ‘holiday heart syndrome’) - Thyroid disorders (especially hyperthyroidism)

Symptoms

• Palpitations (rapid heartbeat sensation)
• Fatigue and weakness
• Dizziness or lightheadedness
• Shortness of breath
• Chest discomfort

Why Is It Important?

• Increased Stroke Risk: Atrial flutter, like atrial fibrillation, can lead to the formation of blood clots in the heart, which may travel to the brain and cause a stroke.
• May Progress to Atrial Fibrillation: Many patients with atrial flutter eventually develop atrial fibrillation.
• Reduced Heart Function: Persistent atrial flutter can weaken the heart over time.

Diagnosis and Management

1. ECG and Holter Monitoring

• A standard ECG is enough for the diagnosis in most cases.
• A Holter monitor may be used for detecting intermittent episodes.

2. Treatment Options

Rate Control:

• Medications like beta-blockers or calcium channel blockers slow down the ventricular rate.

Rhythm Control:

• Electrical Cardioversion: A controlled shock restores normal rhythm.
• Antiarrhythmic Medications: Like amiodarone or flecainide to maintain sinus rhythm.
• Catheter Ablation: A highly effective procedure that destroys the abnormal electrical circuit.

Stroke Prevention

• Anticoagulants (e.g., warfarin, DOACs) for patients at high risk.

Conclusion

Atrial flutter is a significant arrhythmia with serious complications if untreated. Proper diagnosis via ECG and appropriate management can reduce risks and improve quality of life.

Source recommendations

1. American College of Cardiology/American Heart Association/Heart Rhythm Society Guideline on the Management of Patients With Atrial Fibrillation

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193
2. https://pubmed.ncbi.nlm.nih.gov/38033089/
3. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000665
4. https://pubmed.ncbi.nlm.nih.gov/24682348/
5. https://www.hrsonline.org/guidance/clinical-resources/2023-accahaaccphrs-guideline-diagnosis-and-management-patients-atrial-fibrillation

2. European Society of Cardiology Guidelines for the Diagnosis and Management of Atrial Fibrillation

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Atrial-Fibrillation
2. https://academic.oup.com/eurheartj/article/42/5/373/5899003
3. https://www.escardio.org/static-file/Escardio/Guidelines/Documents/ehaa612.pdf
4. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193
5. https://pubmed.ncbi.nlm.nih.gov/32860505/