Preexcitation with Multiple Accessory Pathways as a First Presentation of Undiagnosed Late Stage Ebstein’s Anomaly in an Adult

Ebstein’s anomaly (EA) is a relatively rare congenital heart disease that has long been a challenge both to cardiac surgeons and electrophysiologists. In addition to the hemodynamic burden of the tricuspid valve defect itself, the electrocardiogram (ECG) is abnormal in most cases with a high incidence of tachyarrhythmias, that can often be imputable to accessory atrioventricular pathways mostly located along the tricuspid posterior and septal valve leaflets, and rarely, to multiple accessory pathways. We here report the case of a 19-year-old girl with no known cardiac history, in whom a late stage EA with Eisenmenger syndrome, was diagnosed following a syncopal episode attributed to preexcited atrial tachy-fibrillation with an aspect consistant with multiple accessory pathways with at least one of them being right postero-septal. The patient’s management was very challenging for the heart team considering the fixed pulmonary hypertension and the fact she was reluctant to catheter ablation. This case report underlines the importance of early diagnosis and treatment of EA and its rhythmic complications and explores the anatomic peculiarities of this disease with attention to features that could be important to both arrhythmogenesis and ablation therapy in this unique population.