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.