Abstract
BACKGROUND: Posteroseptal accessory pathways (APs) located inside the coronary sinus (CS) diverticulum pose unique challenges to successful ablation. CASE SUMMARY: A 62-year-old woman with Wolff-Parkinson-White syndrome had 2 previous unsuccessful ablation attempts for the right posteroseptal AP inside the CS diverticulum. She subsequently underwent 3-dimensional (3D)-guided mapping and successful ablation of the AP within the body of the CS diverticulum using the internal jugular vein (IJV) approach. DISCUSSION: Posteroseptal APs located inside the CS diverticulum are one of the reasons for unsuccessful ablation. CS venography can outline the diverticulum anatomy, and complete mapping is essential to identify the earliest and fused signals. The superior IJV approach may be considered in cases of difficulty in mapping and stabilizing the ablation catheter compared with the femoral approach. 3D-guided mapping further assists in detailed AP mapping and locating the earliest site for successful ablation. TAKE-HOME MESSAGES: 3D-guided mapping and a superior IJV approach were key to achieving successful mapping and ablation after previous unsuccessful attempts.