Organised atrial fibrillation simulating atrial flutter

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Arrhythmias

Background:

• Drug-refractory paroxysmal atrial fibrillation (AF) poses a clinical challenge.
• Distinguishing between organized atrial flutter and atrial fibrillation can be difficult.
• Accurate diagnosis is crucial for effective treatment of complex arrhythmias.

Observation:

• A patient presented with paroxysmal atrial fibrillation alternating with a regular rhythm resembling atrial flutter.
• Initial diagnosis suggested isthmus-dependent atrial flutter, treated with cavotricuspid isthmus ablation.
• Recurrent arrhythmias prompted further investigation, revealing organized slow atrial fibrillation on electrophysiological study.

Findings:

• The regular rhythm initially interpreted as atrial flutter was confirmed as organized slow atrial fibrillation.
• Circumferential pulmonary vein ablation was performed.
• This ablation strategy resulted in the complete resolution of both paroxysmal atrial fibrillation and organized slow atrial fibrillation.

Implications:

• This case underscores the importance of detailed electrophysiological mapping in diagnosing complex atrial arrhythmias.
• Organized slow atrial fibrillation can mimic typical atrial flutter, necessitating advanced diagnostic approaches.
• Pulmonary vein isolation may be an effective treatment for certain forms of organized atrial fibrillation presenting concurrently with typical atrial fibrillation.