Pediatric Tachyarrhythmias

You are dispatched to a residence on a report of a child with an altered mental status. Upon arrival, you find an 8 year old boy lying on the couch responsive to verbal stimuli. His mother states he had been playing outside today when he came inside and complained of extreme weakness. He laid on the couch to rest and the mother was unable to rouse him.


  • WPW syndrome


  • None


  • Penicillin


  • BP -90/58
  • HR -190
  • BSL- 98
  • O2 sats – 95% with clear lung sounds


  • 50 inches tall, 57 lbs (25.9kg)


  • Monitor applied showing a rapid, narrow complex tachycardia.
  • Oxygen via NC at 2lpm
  • Vagal maneuvers

Attempts to slow heart rate by vagal maneuvers prove inadequate. The pt is seemingly becoming more lethargic. IV 22g is established in the right AC.

  • Adenosine
    • 0.1 mg/kg = 2.6 mg
      • IV
      • Rapid flush with 20 ml saline
    • repeat double the original dose x1 = 5.2 mg

Adenosine proves ineffective in reducing heart rate and child continues to deteriorate in condition.

  • Medical control contacted for Synchronized cardioversion
    • 1 J/kg = 26 j
    • Repeat to 2 J/kg = 52 j

Patient is successfully converted to a normal sinus rhythm. He becomes alert and is able to answer questions appropriately,  though he complains of some weakness and tiredness.

  • Causes of SVT in children

    • Wolff-Parkinson-White syndrome
      • Most common type of SVT in children
      • Extra pathway within the heart’s electrical system that connects the atria to the ventricles
        • Typically only AV node is the connection (causing a short circuit)
      • Most of the time this doesn’t affect the rhythm
        • Early beat (PAC,PVC) will cause the impulse to travel through AV node and back through extra circuit
            • “Dog chasing its tail”
      • Be conscientious of using AV blocking medications (i.e. Adenosine, diltiazem, verapamil, etc.) in A-fib with accompanying WPW; can result in V-Fib; cardioversion is the gold standard for unstable A-Fib with WPW patients

A-Fib wWPW

Atrial Fibrillation with WPW

    • Atrioventricular Reentrant tachycardia
      • 10% of cases of SVT in children
      • “Pacemaker” or extra focus that is located above the SA node and beats faster.
      • Diagnosis and treatment of both are similar to all forms of SVT

pediatric svt

Pediatric SVT

    • Almost all SVT cases have excellent outcomes and quality of life
      • Avoid caffeine
      • Certain medications
    • Generally, no restrictions are necessary unless extenuating circumstances. Activities involving climbing or heights are discouraged due to dizziness/fainting associated with episodes, resulting in a fall.

2 thoughts on “Pediatric Tachyarrhythmias

  1. My daughter was diagnosed with WPW when she was 3. She had very little issues from it, but it was always a concern , especially during surgery. She finally had an ablation done just under 2 years ago and just earlier this week she was released from regular cardiac follow up. It is truly amazing that a condition is such a big part of your life and then it is gone, just like that. Pretty cool though. Thanks for sharing, hope you don’t mind me sharing on my page.


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