Radiofrequency ablation of the cavotricuspid isthmus for management of atrial flutter in patients with congenital heart disease after tricuspid valve surgery: A single-center experience

Background: Typical atrial flutter involving the cavotricuspid isthmus (CTI) is the most common reentrant arrhythmia in congenital heart disease and ablation is effective in its management. However, congenital heart disease patients often require surgical interventions on their tricuspid valve that utilize prosthetic material, making CTI ablation technically challenging. Objective: To describe the techniques and outcomes of CTI ablation in the presence of prior tricuspid valve repair or replacement. Methods: We included all patients who had undergone tricuspid valve repair utilizing an annuloplasty ring or tricuspid valve replacement who underwent CTI ablation for treatment of atrial arrhythmias between 2005 and 2017. Acute procedural success was defined as demonstration of bidirectional conduction block across the CTI. Long-term success was defined as lack of arrhythmia recurrence on monitoring or related symptoms. Results: Sixteen patients met the inclusion criteria. Twelve (75%) patients had Ebstein's anomaly, 14 (88%) patients had a prosthetic tricuspid valve, and 2 (12%) patients had annuloplasty ring. Acute success was achieved in all cases, with no complications. Radiofrequency ablation was required on the ventricular side in 9 (56%) patients. In 1 case, ablation in the small cardiac vein was required. All patients remained free from atrial flutter during 18 months follow-up (range, 1–101 months). Conclusion: Our study demonstrates the safety and efficacy of catheter ablation of the CTI in the presence of a tricuspid annuloplasty ring or a prosthetic tricuspid valve. This may require ablation from the ventricular side of the valve to target atrial tissue rendered inaccessible as a result of tricuspid valve surgery.