During RF ablation for AVNRT, what is typically observed?

• A. Non-inducible tachycardia
• B. Must ablate in NSR and look for slow junctional beats
• C. Ablate during tachycardia and observe AH jump
• D. Immediate ventricular ectopy

Answer: (B)

During RF ablation for AVNRT, the procedure is usually performed in normal sinus rhythm. This setup lets you monitor how the AV node’s conduction changes as you modify the slow pathway. A hallmark sign of successful slow-pathway modification is the appearance of slow junctional beats—junctional activity that originates from the AV node and runs at a slower rate than the atrial rhythm. This slower junctional rhythm reflects that the slow pathway’s contribution to conduction is being suppressed, which is the goal of the ablation.

After the ablation, it’s common to find that the tachycardia is no longer inducible, but that outcome is assessed after energy delivery rather than observed as the immediate procedural hallmark. Ventricular ectopy is not a desired or typical indicator of successful ablation.