For AVNRT to occur, a patient must have dual nodal physiology, i.e., slow and fast pathway of AVN. True/False?

For AVNRT to occur, a patient must have dual nodal physiology, i.e., slow and fast pathway of AVN. True/False?

• A. True
• B. False
• C. Not applicable
• D. Depends on patient

Answer: (A)

AVNRT arises when there are two distinct conduction pathways in or near the AV node—a slow pathway and a fast pathway. This setup creates a reentrant circuit around the AV node. In the typical AVNRT pattern, the impulse travels antegradely down the slow pathway, which has a longer conduction time, and returns retrogradely through the fast pathway once its refractoriness has recovered. This looping conduction sustains the tachycardia. Because a reentrant tachycardia in this region depends on having two usable pathways with different conduction and refractory properties, the presence of dual AV nodal physiology is what makes AVNRT possible. There are rare atypical variants, but the standard teaching is that dual pathways are required for AVNRT to occur, so the statement is true.

AVNRT arises when there are two distinct conduction pathways in or near the AV node—a slow pathway and a fast pathway. This setup creates a reentrant circuit around the AV node. In the typical AVNRT pattern, the impulse travels antegradely down the slow pathway, which has a longer conduction time, and returns retrogradely through the fast pathway once its refractoriness has recovered. This looping conduction sustains the tachycardia. Because a reentrant tachycardia in this region depends on having two usable pathways with different conduction and refractory properties, the presence of dual AV nodal physiology is what makes AVNRT possible. There are rare atypical variants, but the standard teaching is that dual pathways are required for AVNRT to occur, so the statement is true.