A Heart Rate the Monitor Refuses - Pediatrics clinical simulation case. A 2-month-old infant girl, irritable and pale, with caregiver-reported tachypnea...
A 2-month-old infant girl, irritable and pale, with caregiver-reported tachypnea all day. Pre-hospital monitor displayed a regular narrow-complex rhythm at 294 bpm with no discernible beat-to-beat variability, prompting an emergent Code Pediatric activation.
Acute Resuscitation Milestones & Priorities
Clinical phases and key interventions encountered in this emergency module:
In an infant, a regular narrow-complex tachycardia exceeding 220 bpm with no rate variability is supraventricular tachycardia (SVT) until proven otherwise; sinus tachycardia rarely exceeds 200 bpm and retains variability.
The diving reflex via facial ice-water application is the only developmentally appropriate vagal maneuver in infants; carotid sinus massage, forced Valsalva, and ocular pressure are contraindicated.
Pediatric adenosine first dose is 0.1 mg/kg (max 6 mg) as a rapid IV push through a proximal vein followed by a saline bolus; the brief asystole confirms AV-nodal blockade and often unmasks underlying atrial activity.
A post-conversion delta wave with short PR interval in an infant with SVT indicates Wolff-Parkinson-White syndrome and an accessory pathway that adenosine does not treat; pediatric cardiology consultation and electrophysiology referral are mandatory.
Adenosine doses must be weight-based in infants — flat 6 mg adult dosing and slow infusion both fail because adenosine is metabolized within seconds by endothelial adenosine deaminase.
Calcium channel blockers (e.g., diltiazem) and digoxin monotherapy are contraindicated as first-line therapy in infantile WPW because they can accelerate accessory pathway conduction and precipitate ventricular fibrillation.
Test Your Clinical Reasoning in Real Time
Step into the active clinician role for this case. Order diagnostic tests, analyze live laboratory panels, and navigate branching clinical decisions with real-time feedback.