Orthodromic conduction in AVRT is characterized by?

• A. Down The AV Node And Up The Pathway
• B. Down The Pathway And Up The AV Node
• C. Only Within The AV Node
• D. From Ventricle To Atrium

Answer: (A)

Orthodromic AVRT involves the impulse traveling antegrade through the AV node to activate the ventricles, then returning retrograde through the accessory pathway from the ventricles back to the atria to complete the reentrant loop. This pattern explains why the ventricular activation occurs via the normal His-Purkinje system, typically producing a narrow QRS tachycardia, while the atria are reactivated retrogradely through the accessory pathway.

In contrast, antidromic conduction would mean antegrade through the accessory pathway and retrograde through the AV node, which often yields a wide QRS tachycardia. Saying the impulse travels only within the AV node or merely from ventricle to atrium misses the reentrant circuit directions that define orthodromic AVRT.