Retrograde Wenckebach is a pacing phenomenon used in SVT evaluation involving which process?

• A. Progressive Retrograde Conduction Block
• B. Antegrade Block
• C. Simultaneous Activation
• D. No Change

Answer: (A)

Retrograde Wenckebach describes progressive retrograde conduction block during ventricular pacing. As pacing stimuli reach the ventricles, the time it takes for impulses to travel backward to the atria (ventriculoatrial conduction) lengthens with each beat, until a retrograde signal is not conducted at all. This decremental retrograde conduction pattern—ending in a dropped atrial activation—is what defines the phenomenon. It’s used in SVT evaluation to assess VA conduction and to infer whether the retrograde pathway is nodal (decremental) rather than via a non-decremental pathway like an accessory tract. The other options don’t fit because they don’t describe a progressively delaying retrograde conduction pattern.