True or False: administering adenosine will terminate Atrial Tachycardia?

• A. True
• B. False
• C. Sometimes
• D. Never

Answer: (B)

Adenosine works mainly by briefly blocking the AV node, which can interrupt tachycardias that rely on AV-nodal conduction to sustain the rhythm, such as AV nodal reentrant tachycardia or AVRT. Atrial tachycardia starts in atrial tissue and typically does not depend on the AV node to keep going, so stopping AV conduction doesn’t usually stop the atrial tachycardia itself. It may slow ventricular response or reveal the underlying atrial rhythm, but the atrial tachycardia generally persists. That's why the statement is false; adenosine is not a reliable way to terminate atrial tachycardia, though it can be helpful diagnostically.