What does VANERP look like?

• A. VP and Vent capture, with retrograde A conduction.
• B. VP and Vent capture, but retrograde A conduction is possible.
• C. VP and Vent capture, but no retrograde A conducted.
• D. Atrial capture only.

Answer: (C)

VANERP is used to test whether there is retrograde conduction from the ventricle back to the atrium during ventricular pacing. When you pace the ventricle and you have ventricular capture, you expect to see a clear ventricular depolarization (a paced QRS). If retrograde conduction to the atrium exists, an atrial activation (a P wave or atrial electrogram) will follow the ventricular beat. If there is no retrograde conduction, the atrial channel shows no activation after that ventricular beat.

So the look of VANERP in this scenario is ventricular pacing with successful ventricular capture, but no retrograde atrial conduction. The other possibilities would show an atrial response after pacing (retrograde conduction) or atrial capture, which is not observed here.