Atrial Flutter with Aberrancy

Introduction

Atrial flutter with aberrancy is a cardiac arrhythmia where the atria beat rapidly, and the electrical impulses travel through the ventricles abnormally. This condition can mimic ventricular tachycardia, making accurate diagnosis crucial.

What is Atrial Flutter?

Atrial flutter (AFL) is a type of supraventricular tachycardia (SVT) where the atria contract quickly in a regular pattern, typically around 250-350 beats per minute. Due to the atrioventricular (AV) node’s filtering effect, only some of these rapid impulses reach the ventricles, often leading to a ventricular rate of 150 bpm (2:1 conduction) or other variations.

What is Aberrancy?

Aberrancy occurs when electrical impulses conduct abnormally through the ventricles due to a pre-existing conduction delay, most commonly in the bundle branches. This may lead to a wide QRS complex on the ECG, making the rhythm appear similar to ventricular tachycardia.

Causes and Risk Factors

• Structural heart disease (e.g., ischemic heart disease, cardiomyopathy)
• Hypertension
• Previous myocardial infarction
• Electrolyte imbalances
• Use of antiarrhythmic drugs or beta-blockers
• Hyperthyroidism

Symptoms

• Palpitations
• Dizziness or lightheadedness
• Shortness of breath
• Chest discomfort
• Syncope (in severe cases)

Diagnosis

Electrocardiogram (ECG) Findings:

• Regular atrial activity with flutter waves (sawtooth pattern, best seen in leads II, III, and aVF)
• Narrow or wide QRS complexes: Aberrant conduction results in wide QRS complexes, potentially mimicking ventricular tachycardia.
• Fixed AV ratio, such as 2:1, 3:1, or variable conduction pattern.

Differentiating Atrial Flutter with Aberrancy from Ventricular Tachycardia

Because the wide QRS complex can resemble ventricular tachycardia, certain criteria help distinctions: - History of atrial flutter or supraventricular tachycardia - Stable hemodynamics (VT is more likely if the patient is unstable) - Response to vagal maneuvers or adenosine (SVT with aberrancy often slows or converts, VT usually does not) - ECG criteria: Brugada criteria or Wellens' criteria aid in differentiation.

Treatment

Acute Management:

• Stable patient:
  • Rate control with beta-blockers or calcium channel blockers
  • Consider antiarrhythmic drugs like amiodarone
  • Attempt vagal maneuvers or adenosine if unsure between SVT vs. VT
• Unstable patient:
  • Immediate synchronized cardioversion

Long-term Management:

• Catheter ablation of the atrial flutter circuit in the right atrium is often curative.
• Anticoagulation if atrial flutter is persistent or associated with atrial fibrillation, following CHA₂DS₂-VASc scoring.
• Rate or rhythm control based on patient status and comorbidities.

Conclusion

Atrial flutter with aberrancy is a diagnostically challenging but treatable condition. Proper ECG interpretation and clinical assessment are critical to distinguishing it from ventricular tachycardia. Early diagnosis and appropriate management can significantly improve patient outcomes.

Source recommendations

1. 2023 ESC Guidelines for the Management of Patients with Supraventricular Tachycardia

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Supraventricular-Tachycardia
2. https://pubmed.ncbi.nlm.nih.gov/31504425/
3. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/CVD-and-Diabetes-Guidelines
4. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193
5. https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2019/09/10/12/36/2019-ESC-Guidelines-for-Supraventricular-Tachycardia

2. AHA/ACC/HRS Guideline for the Evaluation and Management of Atrial Arrhythmias

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193
2. https://www.heartrhythmjournal.com/article/S1547-5271(22)01946-4/fulltext
3. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
4. https://www.jacc.org/doi/10.1016/j.jacc.2014.03.021
5. https://www.ahajournals.org/doi/10.1161/cir.0000000000000499