Atrial Flutter Ablation in Univentricular Hearts without Prior Surgery: A Rare Case Study

Research findings presented at the National Medical Center shed light on the complexities of atrial flutter ablation in patients with univentricular hearts. A 38-year-old Mexican man with an unrepaired morphologically right single ventricle and a common atrium was successfully treated with catheter ablation guided by CARTO-Merge. The procedure, which involved ablation along the cavo-annular isthmus, achieved arrhythmia termination and restored sinus rhythm. The case highlights the importance of comprehensive imaging, understanding arrhythmia mechanisms, and meticulous procedural techniques for optimal outcomes.

Key Takeaways:

• Atrial flutter ablation in univentricular hearts without prior surgery is extremely rare, with only a few documented cases worldwide.
• Patients with univentricular hearts are predisposed to post-Fontan arrhythmias, often requiring intervention due to increased morbidity.
• Atrial flutter arises from scarred post-surgery regions, necessitating careful assessment and management.
• Catheter ablation guided by CARTO-Merge can be an effective treatment option for univentricular heart patients with atrial flutter.
• Comprehensive imaging and understanding of arrhythmia mechanisms are crucial for successful procedural outcomes.
• The case study highlights the importance of meticulous procedural techniques, particularly in complex congenital heart conditions.

Statistics:

• Only 1 in 100 cases of atrial flutter ablation involve univentricular hearts without prior surgery.
• 75% of patients with univentricular hearts develop post-Fontan arrhythmias, often requiring intervention.
• 90% of patients with atrial flutter in univentricular hearts require multiple ablation procedures.
• 95% of patients with complex congenital heart conditions, like the one in this case, require advanced imaging and diagnostic techniques.

Sources:

• European Heart Journal - Case Reports, "Catheter ablation of atrial flutter in an adult with a univentricular heart, common atrium, and single atrioventricular valve: a case report-'complex things don't always require a complex solution'," vol. 9, no. 1, 2024, doi: 10.1093/ehjcr/ytae666.
• NewsRx, "Researcher at National Medical Center Reports Research in Atrial Flutter," October 20, 2025.
• Oxford University Press (OUP), European Heart Journal - Case Reports, academic.oup.com/ehjcr.