Introduction
Episodes of atrial fibrillation (AF) are mainly initiated by triggers from the pulmonary veins.1 The superior vena cava (SVC) has been identified as a second major substrate of non-PV foci that accounts for 5–10% of all AF causes.2,3 The electrical disconnection of the SVC from the right atrium is feasible, and SVC isolation (SVCI) in addition to PV isolation (PVI) improve the outcomes of AF ablations.4,5 Despite its efficacy, empirical SVCI is not a common procedure because some complications may develop after the ablation, such as phrenic nerve paralysis, sinus node injury, and SVC stenosis.
Previous research studies demonstrated no evidence of SVC stenosis following SVCI at three months after the procedure.6However, only a few published reports have conducted quantitative assessments of the SVC area. In this study, we evaluated the SVC area four months after the ablation, and in subsequent followed periods.