What is VAERP?

What is VAERP?

• A. The longest S1-S2 that fails to conduct to the atrium
• B. The longest S1-S2 that fails to conduct to the ventricle
• C. The longest S1-S2 that conducts to the atrium
• D. The longest S1-S2 that captures the atrium

Answer: (A)

VAERP is the retrograde ventriculo-atrial effective refractory period. It is defined as the longest S1-S2 interval that fails to produce atrial activation after a ventricular extrastimulus. In practice, you pace the ventricle with a train (S1) and deliver a premature S2 at progressively shorter intervals; the interval at which S2 no longer conducts back to the atrium is the VAERP. This focuses on retrograde conduction from ventricle to atrium, distinguishing it from the ventricular ERP, which is the longest S1-S2 that fails to capture the ventricle. The option describing the longest S1-S2 that fails to conduct to the atrium matches this concept.

VAERP is the retrograde ventriculo-atrial effective refractory period. It is defined as the longest S1-S2 interval that fails to produce atrial activation after a ventricular extrastimulus. In practice, you pace the ventricle with a train (S1) and deliver a premature S2 at progressively shorter intervals; the interval at which S2 no longer conducts back to the atrium is the VAERP. This focuses on retrograde conduction from ventricle to atrium, distinguishing it from the ventricular ERP, which is the longest S1-S2 that fails to capture the ventricle. The option describing the longest S1-S2 that fails to conduct to the atrium matches this concept.