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 V1 ; and a precordial QRS transition at lead V3 . 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.