PALS Tachycardia 4

Question 1

A 5-year-old presents with palpitations, pallor, and a heart rate of 240 bpm. After ice pack application to the face, the rate abruptly converts to 95 bpm. What rhythm did this child most likely have?

Accepted Answer

SVT

Answer

The abrupt conversion to normal rate following a vagal maneuver (ice pack facial immersion) is characteristic of SVT, which terminates abruptly rather than gradually.

Question 2

Which ECG finding is most characteristic of ventricular tachycardia (VT) compared to SVT with aberrancy?

Accepted Answer

AV dissociation visible on the tracing

Answer

AV dissociation (independent P waves and QRS complexes) is a classic marker of ventricular tachycardia that helps distinguish it from SVT with aberrancy.

Question 3

A 9-year-old with Wolff-Parkinson-White (WPW) syndrome develops rapid atrial fibrillation. Which drug should be AVOIDED?

Accepted Answer

Adenosine

Answer

Adenosine (and AV nodal blocking agents) should be avoided in WPW with atrial fibrillation as they can accelerate conduction through the accessory pathway, causing VF.

Question 4

What is the correct energy dose for the SECOND attempt at synchronized cardioversion in a child with unstable SVT if the first attempt at 1 J/kg was unsuccessful?

Accepted Answer

2 J/kg

Answer

PALS guidelines recommend escalating synchronized cardioversion from 0.5-1 J/kg to 2 J/kg for the second and subsequent attempts.

Question 5

A nurse asks why the defibrillator must be in 'synchronized' mode before cardioverting SVT. What is the correct explanation?

Accepted Answer

To avoid delivering a shock during the vulnerable T-wave period

Answer

Synchronized cardioversion delivers the shock on the R wave to avoid the vulnerable T-wave repolarization period, which could trigger ventricular fibrillation.

PALS - Pediatric Advanced Life Support Practice Test

PALS - Pediatric Advanced Life Support Practice Test

PALS Tachycardia 4