Accurate Localization and Catheter Ablation of Superoparaseptal Accessory Pathways

Background There remains some confusion delineating the accurate location and the detailed anatomical relationship between atrioventricular accessory pathways (APs) located in the superoparaseptal region. Objective The purpose of this article was to detail the anatomical relationship and accurate location of APs located in the superoparaseptal region. Methods Between May 1, 2009 and November 30, 2016, 11 patients with superoparaseptal APs (SPS-APs) were identified in 129 consecutive patients who underwent catheter ablation for APs in our center. Results A single SPS-AP was detected in all patients (manifest, n = 5; concealed, n=6). The location of all 11 APs were precisely identified at the region millimeters superior to the His bundle recording site at the tricuspid annulus (S-HB, n=6; manifest, n = 4); the area millimeters behind the His bundle recording site, adjacent to the right atrial aspect of the noncoronary aortic cusp (B-HB, n=2; manifest, n=1); and the true para-His bundle region (P-HB, n=3). The electrocardiogram of all 5 manifest APs conformed to the typical "anteroseptal AP" pattern: a positive delta wave in leads I, II, avF, and avL; a narrow positive delta wave in lead V 1 ; and a precordial QRS transition at lead V 3 . All APs were successfully eliminated by catheter ablation. After 54 ± 26 months of follow-up, all patients were free of arrhythmia. Conclusion Three distinct regions are identified for localization of SPS-APs. Careful mapping and a detailed understanding of the anatomy of this region as well as distinct electrocardiographic characteristics are essential to eliminate such APs safely and effectively.