A challenging and rare ablation of both epicardial and endocardial accessory pathway in a patient with paroxysmal supraventricular tachycardia

Background:The standard approach for treating patients with paroxysmal supraventricular tachycardia(PSVT) is radiofrequency ablation. In patients with PSVT difffculty in ablation of accessory pathways(APs) is associated with failures and recurrences. Existence of epicardial and endocardial AP is a special case resulting in difffculties in radiofrequency ablation. Case presentation: A 54-year-old female had a symptom of recurrent palpitation for 40 years. The electrocardiogram(ECG) showed supraventricular tachycardia. As the tachycardic episodes had been poorly controlled with conservative treatment, the patient underwent radiofrequency ablation. Invasive electrophysiology study performed and confirmed that the rare occurrence of both endocardial and epicardial AP in this case. The accessory pathways were epicardial AP of mitral valve annulus and endocardial AP of tricuspid annulus and mitral annulus posterior septum. Both epicardial and endocardial AP in one case was rare, however, ablation of this challenging and rare case is successful.The patient's ECG was normal after operation.. During the follow-up, the patient has had no recurrent tachycardia. Conclusions: This rare and challenging case offers evidence for viable technique of epicardial ablation when conventional endocardial ablation process fail to block the AP conduction. As in this case, repeat strategy of electrophysiological study and precise mapping by an experienced operator should be a prerequisite to attempt ablation treatment.