Epinephrine (0.01 mg/kg IV/IO) is the first-line drug for bradycardia unless it is caused by increased vagal tone or AV block, in which case atropine is used.

If SVT is unstable (poor perfusion, hypotension, altered mental status), synchronized cardioversion (0.5-1 J/kg) is required.

While wide QRS tachycardia suggests VT, SVT with aberrant conduction can also present with a wide QRS.

The initial pediatric defibrillation dose is 2 J/kg, increasing to 4 J/kg if needed.

QT prolongation predisposes to Torsades de Pointes, a form of polymorphic VT that may require IV magnesium sulfate.

Atrial fibrillation is rare in children unless they have an underlying cardiac condition (e.g., congenital heart disease, cardiomyopathy).

Peaked T waves are one of the first ECG signs of hyperkalemia, which can progress to widened QRS and cardiac arrest if untreated.

Hypoxia leads to bradycardia due to inadequate oxygenation, making oxygenation and ventilation the first priorities in treatment.

Adenosine (0.1 mg/kg IV push, max 6 mg first dose) is the preferred initial treatment for stable SVT.

Epinephrine (0.01 mg/kg IV/IO) should be given every 3-5 minutes during cardiac arrest to improve coronary and cerebral perfusion.

Severe hyperkalemia widening the QRS complex can evolve into a sine wave pattern, leading to asystole.

PEA and asystole are the most common arrest rhythms in children due to respiratory failure or shock, while VF is rare.

PEA is a non-shockable rhythm and requires CPR, epinephrine, and treatment of reversible causes (H’s & T’s).

In infants, SVT often exceeds 220 bpm, while in older children, it is typically >180 bpm.

Mobitz II can progress to complete heart block, so it often requires pacing if symptomatic.