A 55-year-old man on ICU develops a regular narrow-complex tachycardia at 190 bpm. The team gives IV adenosine 6 mg rapid push. The tachycardia termin...

Question

A 55-year-old man on ICU develops a regular narrow-complex tachycardia at 190 bpm. The team gives IV adenosine 6 mg rapid push. The tachycardia terminates transiently but restarts after 10 seconds. What does this response to adenosine indicate about the tachycardia mechanism?

Accepted Answer

The transient termination and restart is characteristic of AV-nodal re-entrant tachycardia (AVNRT) or AV re-entrant tachycardia (AVRT) - adenosine interrupts the re-entry circuit at the AV node, but the circuit re-initiates; repeat adenosine at 12 mg or consider prophylactic antiarrhythmic therapy

Answer

The tachycardia is ventricular in origin

Answer

Adenosine has failed completely

Answer

The tachycardia is sinus tachycardia

Answer

The patient has atrial fibrillation

uk-fficm MCQ (SBA): Adenosine Response - SVT Diagnosis

A 55-year-old man on ICU develops a regular narrow-complex tachycardia at 190 bpm. The team gives IV adenosine 6 mg rapid push. The tachycardia terminates transiently but restarts after 10 seconds. What does this response to adenosine indicate about the tachycardia mechanism?