What is the rationale for pacing in the SVC while ablating the right-sided (septal) pulmonary veins?

What is the rationale for pacing in the SVC while ablating the right-sided (septal) pulmonary veins?

• A. To pace and capture the phrenic nerve so any damage will be immediately identified
• B. To reset the rhythm
• C. To identify PV ostia
• D. To assess AV conduction

Answer: (A)

Monitoring phrenic nerve function during ablation of the right-sided pulmonary veins by pacing from the SVC is done to detect any phrenic nerve injury in real time. The right phrenic nerve courses close to the SVC and the ostia of the right-sided pulmonary veins, so ablation in this region carries a risk of compromising the nerve. By pacing through the SVC, you can capture the phrenic nerve and observe diaphragmatic movement; if imaging or the capture changes (or is lost) during energy delivery, it signals potential injury and prompts stopping or adjusting the ablation. This safety check helps prevent permanent phrenic nerve damage. It isn’t primarily for resetting rhythm, identifying PV ostia, or assessing AV conduction, which are addressed by other techniques.

Monitoring phrenic nerve function during ablation of the right-sided pulmonary veins by pacing from the SVC is done to detect any phrenic nerve injury in real time. The right phrenic nerve courses close to the SVC and the ostia of the right-sided pulmonary veins, so ablation in this region carries a risk of compromising the nerve. By pacing through the SVC, you can capture the phrenic nerve and observe diaphragmatic movement; if imaging or the capture changes (or is lost) during energy delivery, it signals potential injury and prompts stopping or adjusting the ablation. This safety check helps prevent permanent phrenic nerve damage. It isn’t primarily for resetting rhythm, identifying PV ostia, or assessing AV conduction, which are addressed by other techniques.