HRCR March 2025 Quiz

Editorial note: The following quiz is related to the article How to approach atypical atrioventricular nodal reentry tachycardia induced by double atrial response involving an inferolateral left atrial slow pathway by Yuto Fukuda and colleagues in the March 2026 issue of Heart Rhythm Case Reports.

1. Which of the following findings is most consistent with a double atrial response during programed ventricular stimulation in this case.

A. Atrial activation after ventricular pacing with progressively increasing VA intervals, suggestive of concealed entrainment
B. Two atrial activations following a single ventricular beat due to a pseudo-V-A-A response resulting from delayed VA conduction of AVNRT
C. Two atrial electrogram following a single ventricular stimulus, indicating retrograde conduction via dual AV nodal slow pathways
D. Atrial activation occurring without subsequent ventricular conduction, suggestive of lower common pathway block
E. Continuous atrial activity during ventricular pacing without discrete intervals

2. During tachycardia, pacing from the sub-mitral valve region did not reset the tachycardia. What is the significance of this finding?

A. Suggest a left-sided accessory pathway
B. Indicates the presence of concealed entrainment
C. Helps rule out participation of a left-sided accessory pathway in the tachycardia circuit
D. Confirms the mechanism as atrial tachycardia
E. Indicates conduction block in the AV node

3. Which of the following findings most strongly suggests the involvement of an inferolateral left atrial (IL-LA) slow pathway in the tachycardia circuit?

A. Presence of earliest atrial activation at the His bundle during tachycardia
B. The tachycardia terminates during ablation at the right inferior septum but is still inducible.
C. The tachycardia was terminated by atrial extrastimulation delivered from the inferolateral mitral annulus, and pacing from the sub-mitral valve region did not reset the tachycardia
D. The earliest atrial activation was recorded at the mid coronary sinus, and His-refractory extrastimulation from the RV apex failed to reset the tachycardia.
E. During tachycardia, ventricular overdrive pacing from the RV apex produced a V-A-V response with earliest atrial activation at the CS mid.