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.