Major issues for supraventricular tachycardia ablation in patients with persistent left superior vena cava.

The persistent left superior vena cava (PLSVC) is a rare abnormality of the venous system. The ablation of supraventricular tachycardias such as atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) in patients with PLSVC might be challenging due to dislocation of cardiac anatomy and subsequently of the ablation target sites, instability of the ablation catheter and loss of common references in the coronary sinus. The present two cases sought to discuss the most common issues related to catheter ablation of AVNRT and AVRT in patients with PLSVC.