Tachycardia Flashcards
7 cards from real PALS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Tachycardia flashcards as text
A 4-year-old presents with a heart rate of 200 bpm, narrow QRS complexes, and no P waves visible. The child is alert and playing. What is the most likely rhythm?
Answer: Supraventricular tachycardia (SVT)
SVT typically presents with abrupt-onset rates >180-220 bpm, narrow QRS, absent or retrograde P waves, and the child may still be alert if compensated.
Which vagal maneuver is most appropriate as a first-line intervention for a stable child with SVT?
Answer: Valsalva maneuver
The Valsalva maneuver (bearing down or blowing through an occluded straw) is safe and commonly used in older children with stable SVT.
A 7-year-old with SVT fails two doses of adenosine. The child remains stable with a HR of 220 bpm. What is the next recommended intervention?
Answer: Amiodarone 5 mg/kg IV
After adenosine failure in stable SVT, amiodarone 5 mg/kg IV over 20-60 minutes is a recommended second-line agent in PALS.
What is the key ECG feature that distinguishes sinus tachycardia from SVT in an infant?
Answer: Presence of upright P waves before each QRS in leads I and aVF
In sinus tachycardia, normal upright P waves precede each QRS in leads I and aVF, whereas SVT typically lacks visible or has abnormal P waves.
A 2-year-old is brought in with a heart rate of 280 bpm, poor perfusion, and altered mental status. What is the immediate treatment?
Answer: Synchronized cardioversion starting at 0.5-1 J/kg
Unstable SVT with hemodynamic compromise requires immediate synchronized cardioversion at 0.5-1 J/kg, escalating to 2 J/kg if needed.
Which of the following findings would most strongly suggest that an infant's tachycardia is sinus tachycardia rather than SVT?
Answer: Rate variability with activity and crying
Sinus tachycardia varies with physiological stressors such as crying, fever, or agitation, while SVT tends to have a fixed, non-varying rate.
When using synchronized cardioversion for pediatric SVT, what is the recommended initial energy dose?
Answer: 0.5-1 J/kg
PALS guidelines recommend starting synchronized cardioversion for SVT at 0.5-1 J/kg and increasing to 2 J/kg if the initial dose is ineffective.