During EPS, AH jump is an observation typically associated with which phenomenon?

During EPS, AH jump is an observation typically associated with which phenomenon?

• A. AH jump indicates dual nodal physiology
• B. PR interval shortening with AV conduction
• C. QRS widening due to ventricular conduction block
• D. Sinus node dysfunction

Answer: (A)

AH jump shows dual AV nodal physiology. The AV node can have two pathways for atrial impulses—the fast and the slow pathway. When a premature atrial impulse arrives, if the fast pathway is still refractory and the impulse conducts via the slow pathway, the time from atrial activation to the His bundle (the AH interval) lengthens abruptly. This sudden change in conduction time, seen as an AH jump, indicates that two distinct AV nodal pathways exist and can alternate conduction. This dual-pathway setup is the substrate for AV nodal reentrant tachycardia. The other options describe different phenomena not tied to this abrupt switch in AV nodal conduction.

AH jump shows dual AV nodal physiology. The AV node can have two pathways for atrial impulses—the fast and the slow pathway. When a premature atrial impulse arrives, if the fast pathway is still refractory and the impulse conducts via the slow pathway, the time from atrial activation to the His bundle (the AH interval) lengthens abruptly. This sudden change in conduction time, seen as an AH jump, indicates that two distinct AV nodal pathways exist and can alternate conduction. This dual-pathway setup is the substrate for AV nodal reentrant tachycardia. The other options describe different phenomena not tied to this abrupt switch in AV nodal conduction.