Objective:

To report a case of successful radiofrequency catheter ablation of atrial fibrillation in a patient with cor triatriatum sinister, emphasizing the critical role of intracardiac echocardiography and electroanatomic mapping in achieving favorable outcomes.

Key Findings:

• Intracardiac echocardiography was critical for guiding transseptal puncture and ensuring adequate catheter contact, leading to successful ablation.
• Electroanatomic mapping showed a high-voltage area at the fibromuscular membrane, suggesting it contained viable myocardial tissue, which was crucial for the ablation strategy.
• The tailored ablation strategy based on mapping results led to successful outcomes, with no recurrence of atrial fibrillation noted at follow-up.

Interpretation:

The case illustrates the importance of advanced imaging techniques and individualized strategies in catheter ablation for patients with complex congenital heart anomalies.

Limitations:

• The study is based on a single case report, limiting generalizability.
• No volumetric assessment was performed as part of the routine preablation workup.
• Long-term follow-up data on the patient's outcomes post-ablation are lacking.

Conclusion:

This case contributes to the understanding of catheter ablation techniques in patients with cor triatriatum sinister and emphasizes the role of advanced imaging, suggesting potential pathways for future research.