If an SVT terminates without atrial activation upon cessation of VP, the pacing maneuver excludes which tachycardia?

• A. Atrial Tachycardia
• B. AVNRT
• C. AVRT
• D. Sinus Tachycardia

Answer: (A)

The key idea is how the atria respond to ventricular pacing during a supraventricular tachycardia. If you stop ventricular pacing and the tachycardia terminates without any atrial activation detected afterward (no P waves following the last QRS), this means the atria are not driving or sustaining the tachycardia. An atrial tachycardia originates in the atria and would typically continue to generate atrial impulses, so you would expect atrial activity to resume or be evident after pacing is stopped. The absence of atrial activation at termination thus makes an atrial tachycardia unlikely. The other tachycardias listed can be terminated by ventricular pacing through AV nodal or reentrant pathways and do not require ongoing atrial activation, so they remain compatible with this observation.