Cardiovascular Disorders
Arrhythmia and resuscitation drugs
Supraventricular tachycardia: adenosine 0.1 mg/kg rapid IV push (max 6 mg) followed by a rapid saline flush; second dose 0.2 mg/kg (max 12 mg). Amiodarone 5 mg/kg for refractory ventricular fibrillation or pulseless ventricular tachycardia. Digoxin has a narrow therapeutic index, and toxicity is amplified by hypokalemia, hypomagnesemia, hypercalcemia, and renal impairment; digoxin-specific Fab fragments are the antidote. Prostaglandin E1 keeps the ductus open in ductal-dependent lesions - apnea is the expected adverse effect, so be ready to support ventilation.
Heart failure and hypertension
Chronic pediatric heart failure uses diuretics (furosemide, spironolactone), ACE inhibitors or ARBs, and sometimes carvedilol. Pediatric hypertension is classified by age, sex, and height percentile rather than a single cutoff; ACE inhibitors, ARBs, amlodipine, and thiazides are common. Counseling points include avoiding NSAIDs and high-sodium processed foods.
Kawasaki disease and prophylaxis
Kawasaki disease: IVIG 2 g/kg as a single infusion plus high-dose aspirin (80–100 mg/kg/day divided every 6 hours) until fever resolves, then low-dose aspirin (3–5 mg/kg/day) for 6–8 weeks, longer with coronary artery involvement. Aspirin is otherwise avoided in children with viral illness because of Reye syndrome.
Endocarditis prophylaxis
Reserve prophylaxis for the highest-risk lesions - prosthetic valves, prior endocarditis, unrepaired cyanotic congenital heart disease, or repaired lesions with prosthetic material within 6 months. Amoxicillin 50 mg/kg (max 2 g) orally 30–60 minutes before the procedure; clindamycin or a cephalosporin for penicillin allergy.
Worked example
A 20 kg child in SVT: adenosine 0.1 mg/kg = 2 mg, given as a rapid push with immediate flush, then escalated to 0.2 mg/kg = 4 mg if the first dose fails.