During treatment of a child with stable supraventricular tachycardia refractory to initial therapy, the child becomes less conscious with a rapid, weak femoral pulse. The correct next step is to:

• A. Perform immediate synchronized cardioversion and reassess.
• B. Wait and monitor vitals.
• C. Administer adenosine intravenously.
• D. Start external pacing.

Answer: (A)

The key idea is recognizing hemodynamic instability in a child with SVT and acting to restore perfusion quickly. When SVT is compromising consciousness and a weak peripheral pulse, the priority shifts from rhythm definition to rapidly reestablishing adequate cardiac output. Synchronized cardioversion delivers a controlled electrical shock timed to the heart’s rhythm, effectively terminating the tachycardia and stabilizing the patient’s circulation. Adenosine is useful for stable SVT, but it won’t reliably improve perfusion in an unstable child and can delay life-saving treatment. External pacing isn’t the appropriate move here, as the immediate need is to reset the rhythm with a synchronized shock and reassess after stabilization.