In cryoablation for AVNRT, an AV ratio of 1:4-1:10 is acceptable.

In cryoablation for AVNRT, an AV ratio of 1:4-1:10 is acceptable.

• A. True
• B. False
• C. Sometimes
• D. Depends on operator

Answer: (B)

In AVNRT cryoablation, you prioritize accurate localization near the slow pathway and preservation of AV conduction, not a fixed numeric signal ratio. The atrial-to-ventricular (A:V) electrogram amplitude ratio at the ablation site can vary with catheter orientation and tissue contact, and there isn’t a universally accepted target range like 1:4 to 1:10. Mapping relies on identifying slow-pathway potentials, observing how pacing and ablation affect AV conduction, and using cryomapping to test safety before delivering definitive lesions. If cryomapping shows no AV block and the slow-pathway physiology is disrupted, you proceed; if conduction deteriorates, you stop. Therefore, a fixed A:V ratio of 1:4–1:10 is not an acceptable criterion.

In AVNRT cryoablation, you prioritize accurate localization near the slow pathway and preservation of AV conduction, not a fixed numeric signal ratio. The atrial-to-ventricular (A:V) electrogram amplitude ratio at the ablation site can vary with catheter orientation and tissue contact, and there isn’t a universally accepted target range like 1:4 to 1:10. Mapping relies on identifying slow-pathway potentials, observing how pacing and ablation affect AV conduction, and using cryomapping to test safety before delivering definitive lesions. If cryomapping shows no AV block and the slow-pathway physiology is disrupted, you proceed; if conduction deteriorates, you stop. Therefore, a fixed A:V ratio of 1:4–1:10 is not an acceptable criterion.