Pseudo-Conduction After Cavotricuspid Isthmus Ablation: Insights From High-Density Mapping
Youmei Shen1, Shumpei Mori2, Xiang Xue3
1Division of Cardiology, The First Affiliated Hospital With Nanjing Medical University, Nanjing, China; Division of Cardiology, Taizhou School of Clinical Medicine, Nanjing Medical University, Nanjing, China.
Background:
Bidirectional cavotricuspid isthmus (CTI) block is the procedural endpoint of typical atrial flutter ablation, but pseudo-conduction may mimic residual isthmus conduction.
Case Summary:
A 45-year-old man underwent CTI ablation for typical atrial flutter. After linear ablation, a short double-potential interval and simplified differential pacing suggested residual conduction near the inferior vena cava (IVC). Additional ablation at this region failed to change the activation pattern. High-density mapping ultimately confirmed complete CTI block, whereas rapid activation around the IVC reached the lateral right atrium early, creating a pseudo-residual conduction pattern. The patient had no complications and remained free from recurrence during 9-month follow-up.
Discussion:
Rapid conduction around the IVC may confound conventional criteria for CTI block.
Take-Home Message:
High-density mapping may help differentiate true residual conduction from pseudo-conduction and prevent unnecessary ablation.
