Discussion
In this case, insufficient low-output ablation to the PN site caused the
reconduction of the SVC and subsequent AF recurrence. In this session,
the course of the PN was effectively identified by high and low-output
pacing.
We adjusted the output to precisely detect the course of the PN. In
addition, when catheter ablation was performed near the PN where high
out-put pacing captured, we performed CMAP to monitor for the occurrence
of PN injury3. A previous study reported that , to
avoid PN injury, the ablation line was directed parallel to the PN in a
caudal direction. However, this method posed the risk of sinus node
injury if the PN extended near to the sinus node and could not be
performed in case the PN has continuous proximity from the SVC to the
RA4.Our case describes a new approach to prevent PN
injury by making longitudinal lines on both sides of the PN in a cranial
direction. This method could facilitate safe and effective isolation of
NPVF in the SVC with the conventional system, including the cases with
AF foci located on the course of the PN.
In conclusion, longitudinal linear ablation on both sides of the PN may
be a therapeutic option to isolate the SVC and avoid PN injury.