Ectopic potentials in the SVC can act not only as a trigger but also as
a driver of AF. In the present case, the atrium resumed a sinus rhythm
spontaneously on the completion of SVC isolation and AF could no longer
be induced. However, there was residual fibrillatory activity in the
SVC. These findings suggest that residual activity in the SVC worked as
a driver of AF. In the presence of a fibrillatory pattern, conventional
activation mapping techniques cannot map residual SVC activity. ICL
mapping using the CARTO system can identify the target site of ablation
in the isolated SVC.