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Supraventricular tachycardia — RACP Paediatrics MCQ

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HardCardiologySupraventricular tachycardiaRACP Paediatrics

A 3-month-old has regular narrow-complex tachycardia at 250/min with normal blood pressure and capillary refill. A diving-reflex vagal manoeuvre fails and proximal IV access is available. Which first dose and administration method is appropriate?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: E — Give adenosine 100 micrograms/kg by rapid IV push and saline flush while recording ECG

Explanation lettering: D = shown as A · C = shown as B · B = shown as C · A = shown as D

E is correct. ANZCOR recommends adenosine as the preferred medicine for SVT with a pulse. The initial dose is 100 micrograms/kg (maximum 6 mg), delivered rapidly through a proximal IV or IO route, immediately flushed with 0.9% saline and recorded on ECG because the half-life is only seconds. A administers it too slowly to reach the heart effectively and loses diagnostic information. B is not routinely used in children and verapamil is particularly unsafe in infants. C is reserved for refractory SVT with expert advice. D is used for cardiovascular compromise or failed/unavailable adenosine; this infant is stable. Further adenosine doses may escalate according to ANZCOR if the first fails.

Reference: ANZCOR Guideline 12.3: Management of other arrhythmias in infants and children: https://www.anzcor.org/home/paediatric-advanced-life-support/guideline-12-2-paediatric-advanced-life-support-pals-2