Catheter ablation of atrial fibrillation in situs inversus dextrocardia: Challenge, improved procedure, outcomes, and literature review.

Introduction: Catheter ablation for atrial fibrillation (AF-CA) in patients with situs inversus dextrocardia (SID) can be challenging because of the contrary anatomy and associated anomalies. Cases and literature regarding AF-CA in SID are rare and provide little information. Our study aims to present an improved procedure, ablation strategies, and evaluate the safety and outcomes of AF-CA in patients with AF and SID.

Methods: A total of 10 patients with AF-SID (mean age, 60.4 ± 15.7 years; six paroxysmal AF, four persistent atrial fibrillation [PeAF]) were enrolled. For the improved procedure, images obtained by preacquired computed tomography and three-dimensional electroanatomical mapping, integrating intracardiac echocardiography, and x-ray imaging data are necessary to optimize the transseptal puncture and ablation procedure.

Results: All patients successfully underwent 13 AF-CA procedures without complications, including three patients received repeat procedures. However, two PeAF patients presented sick sinus syndrome (SSS) after the AF-CA procedure, and one underwent permanent pacemaker implantation therapy during hospitalization. During the follow-up period (6-72 months), the outcomes were not favorable: three patients (30%) maintained sinus rhythm (SR) after the initial procedure; after repeated procedures, the overall SR rate was 40% (four patients).

Conclusion: With the improved strategy, AF-CA can be safely and effectively performed with low radiation exposure in patients with SID. However, the long-term outcomes were not favorable, even when managed at a tertiary center by a team of specialists. Moreover, patients with PeAF might also have masked SSS, which should be carefully considered.