Epicardial left atrial appendage and biatrial appendage accessory pathways

Area of Science:

• Pediatric Cardiology
• Electrophysiology
• Cardiac Surgery

Background:

• Wolff-Parkinson-White (WPW) syndrome ablation success rates exceed 95%, but complex epicardial connections can cause failure.
• Left-sided accessory pathways, including atrial appendage connections, are less common but increasingly recognized.

Observation:

• Three pediatric patients with high-risk accessory pathways (effective refractory period 190-240 ms) underwent failed endocardial ablation attempts.
• One patient had a left atrial appendage to left ventricle connection; two had biatrial appendage pathways.
• Two patients had a history of ventricular fibrillation, including one cardiac arrest.

Findings:

• Appendages were diffusely adherent to ventricles via fibrofatty connections.
• Surgical dissection of the appendages successfully eliminated pre-excitation and tachycardia in all three patients.
• This highlights the unique anatomy and successful surgical treatment of these rare WPW variants.

Implications:

• Surgical management should be considered for atrial appendage accessory pathways when endocardial ablation is unsuccessful.
• This case series expands understanding of rare WPW anatomies and their treatment.
• Early consideration of surgical intervention may be crucial for high-risk pediatric patients.