3.1 Pediatric Dysrhythmias & ECG Analysis

BCEN CPEN Certified Pediatric Emergency Nurse Exam

Track your progress as you read

Finished sections get a check mark.

1 Chapter 1: Exam Overview, Triage Process & Initial Emergency Assessment

1.1 CPEN Exam Logistics, Blueprint & Certification Overview 1.2 Pediatric Triage Systems & Acuity Categorization 1.3 Pediatric Assessment Triangle (PAT) & Initial Impression 1.4 Primary & Secondary Pediatric Emergency Assessment 1.5 Age-Specific Vital Signs, Developmental Considerations & Pain Scales

2 Chapter 2: Pediatric Respiratory Emergencies

2.1 Upper Airway Obstruction 2.2 Lower Airway Emergencies 2.3 Respiratory Distress vs. Respiratory Failure & Airway Management

3 Chapter 3: Pediatric Cardiovascular Emergencies

3.1 Pediatric Dysrhythmias & ECG Analysis 3.2 Congenital Heart Defects 3.3 Acquired Heart Disease & Heart Failure

4 Chapter 4: Pediatric Neurological Emergencies

4.1 Pediatric Seizures, Status Epilepticus & Febrile Seizures 4.2 Altered Mental Status, Increased ICP & Head Trauma 4.3 Pediatric Central Nervous System Infections

5 Chapter 5: Pediatric Gastrointestinal & Genitourinary Emergencies

5.1 Pediatric GI Surgical Emergencies 5.2 Pediatric Dehydration, Gastroenteritis & Fluid Resuscitation Protocols 5.3 Pediatric GU & Renal Emergencies

6 Chapter 6: Pediatric Endocrine, Metabolic & Hematologic/Oncologic Emergencies

6.1 Diabetic Ketoacidosis (DKA) & Hypoglycemia in Pediatric Emergency Patients 6.2 Electrolyte Imbalances & Inborn Errors of Metabolism 6.3 Sickle Cell Disease Crisis & Pediatric Oncologic Emergencies

7 Chapter 7: Pediatric Musculoskeletal, Integumentary & ENT/Ophthalmic Emergencies

7.1 Pediatric Musculoskeletal Injuries & Fractures 7.2 Pediatric Dermatologic Emergencies & Rashes 7.3 Pediatric ENT & Ocular Emergencies

8 Chapter 8: Pediatric Trauma Emergencies

8.1 Pediatric Trauma Resuscitation & Anatomical Vulnerabilities 8.2 Head, Spinal & Thoracic Trauma in Children 8.3 Abdominal, Pelvic & Extremity Trauma in Pediatric Patients

9 Chapter 9: Child Maltreatment, Toxicology & Behavioral Emergencies

9.1 Child Abuse, Neglect, Non-Accidental Trauma & Mandatory Reporting 9.2 Pediatric Toxicology, Toxidromes & Emergency Antidotes 9.3 Pediatric Behavioral & Mental Health Crisis Management

10 Chapter 10: Pediatric Multi-System Emergencies, Shock & Thermal Injuries

10.1 Pediatric Shock Recognition & Classification 10.2 Pediatric Sepsis, Septic Shock & Multiple Organ Dysfunction Syndrome 10.3 Pediatric Anaphylaxis & Severe Allergic Reactions 10.4 Submersion Injuries, Drowning & Thermal/Burn Emergencies

11 Chapter 11: Professional Practice, Legal, Ethical & Safety Standards

11.1 Legal & Ethical Considerations 11.2 Patient Safety, Medication Error Prevention & Weight-Based Dosing 11.3 Family-Centered Care, Communication & Disaster/Surge Preparedness

3.1 Pediatric Dysrhythmias & ECG Analysis

Key Takeaways Explain This Topic AI

Pediatric dysrhythmias are overwhelmingly secondary to hypoxia, severe acidosis, or structural heart disease, requiring immediate oxygenation and ventilation as primary PALS resuscitation steps.

Sinus Tachycardia (infant HR <220, child HR <180) exhibits rate variability and present P waves, whereas Supraventricular Tachycardia (infant HR ≥220, child HR ≥180) features abrupt onset, fixed rate, and hidden P waves.

Pediatric bradycardia with HR <60 beats/min and signs of poor perfusion despite effective oxygenation/ventilation requires immediate chest compressions and Epinephrine (0.01 mg/kg IV/IO).

Adenosine (initial dose 0.1 mg/kg, max 6 mg) is the first-line chemical cardioversion for stable SVT and MUST be administered via rapid two-syringe push technique followed immediately by a 5–10 mL saline flush.

Unstable dysrhythmias with pulse (SVT, VT) require synchronized cardioversion starting at 0.5 to 1 J/kg, while shockable pulseless arrest rhythms (pVT/VF) require immediate unsynchronized defibrillation at 2 J/kg.

Last updated: July 2026

Pediatric Dysrhythmias & ECG Analysis

Pediatric cardiac dysrhythmias present unique clinical challenges in the emergency department because children rarely present with primary cardiac pathology. In pediatric patients, dysrhythmias are most frequently secondary to hypoxia , acidosis , electrolyte derangements , toxicological ingestions , or congenital heart abnormalities . Pediatric emergency nurses must rapidly recognize abnormal cardiac rhythms, distinguish malignant dysrhythmias from physiological compensatory mechanisms, and execute Pediatric Advanced Life Support (PALS) protocols without delay.

Normal Pediatric ECG Differences & Conduction Physiology

Interpreting a pediatric 12-lead electrocardiogram (ECG) requires a clear understanding of age-specific developmental differences. Infants are born with right ventricular dominance due to high fetal pulmonary vascular resistance. As the child grows, left ventricular mass increases, shifting the electrical axis.

Key Age-Dependent ECG Features

Heart Rate : Baseline heart rates are significantly faster in neonates (100–160 bpm) and infants, gradually decreasing toward adult ranges by adolescence.

QRS Axis : Right-axis deviation (+90° to +180°) is normal in newborns. Left-axis deviation in a neonate suggests congenital structural defects such as tricuspid atresia or an atrioventricular canal defect.

Interval Duration : PR intervals, QRS duration, and QTc intervals are shorter in infants and young children due to smaller cardiac mass and faster conduction velocities (normal infant QRS is <0.08 seconds; child <0.09 seconds).

T-Wave Progression : T waves in leads V1 through V3 are inverted in healthy children from age 1 week up to early adolescence (termed the juvenile T-wave pattern ). An upright T wave in V1 after 7 days of life indicates right ventricular hypertrophy.

Sinus Tachycardia vs. Supraventricular Tachycardia (SVT)

Differentiating Sinus Tachycardia (ST) from Supraventricular Tachycardia (SVT) is one of the most critical diagnostic challenges in pediatric emergency nursing. Misdiagnosing SVT as ST delays essential cardioversion, while misdiagnosing ST as SVT risks administering AV-nodal blocking agents to a patient experiencing compensatory shock.

Diagnostic Parameter Sinus Tachycardia (ST) Supraventricular Tachycardia (SVT)
Infant Heart Rate Typically <220 beats/min Typically ≥220 beats/min
Child Heart Rate Typically <180 beats/min Typically ≥180 beats/min
Onset & Offset Gradual acceleration and deceleration Abrupt, sudden onset ("on/off switch")

Rate Variability Varies continuously with activity, fever, or pain Fixed, monomorphic rate; no beat-to-beat variability

P-Wave Morphology Normal P waves present before every QRS complex Absent, hidden in T wave, or retrograde/inverted P waves

Underlying History Fever, dehydration, hypovolemia, sepsis, pain, anxiety History of irritability, poor feeding, tachypnea, or sudden pallor

Response to Therapy Rate slows as underlying cause is treated (e.g., fluid bolus) Unaffected by antipyretics or fluid resuscitation

Pediatric Bradycardia Management

In pediatric patients, bradycardia is an ominous sign of impending cardiac arrest . Unlike adults, where bradycardia is frequently primary cardiac in origin (e.g., ischemia), pediatric bradycardia is almost exclusively caused by profound tissue hypoxia , severe hypovolemia , or hypercapnia .

Clinical Threshold & PALS Algorithm

Initial Assessment : Assess airway, breathing, and circulation. Administer 100% supplemental oxygen and provide effective bag-valve-mask (BVM) ventilation if respiratory effort is inadequate.

Indications for CPR : If the heart rate remains <60 beats/min with signs of poor systemic perfusion (altered mental status, weak central pulses, delayed capillary refill >3 seconds, hypotension) despite adequate oxygenation and ventilation, immediately initiate chest compressions .

Pharmacological Interventions :

Epinephrine : First-line medication for symptomatic bradycardia refractory to ventilation. Dosage: 0.01 mg/kg IV/IO (0.1 mL/kg of 0.1 mg/mL concentration). Repeat every 3 to 5 minutes.

Atropine : Indicated instead of epinephrine if bradycardia is caused by increased vagal tone (e.g., post-endotracheal intubation suctioning), primary AV block , or organophosphate poisoning . Dosage: 0.02 mg/kg IV/IO (minimum single dose 0.1 mg to avoid paradoxical bradycardia; maximum single dose 0.5 mg in children, 1.0 mg in adolescents).

Pediatric Cardiac Arrest Rhythms

Pediatric cardiac arrest is classified into non-shockable and shockable rhythms. Non-shockable rhythms account for over 80–90% of out-of-hospital pediatric cardiac arrests.

Non-Shockable Rhythms: Asystole & Pulseless Electrical Activity (PEA)

Pathophysiology : Result from progressive respiratory failure, hypoxic-ischemic collapse, or uncompensated shock.

Management : High-quality CPR (15:2 compression-to-ventilation ratio for two rescuers), continuous chest compressions once an advanced airway is placed (1 ventilation every 2–3 seconds), and Epinephrine 0.01 mg/kg IV/IO administered as early as possible (within 5 minutes of arrest onset). Search for and treat reversible causes ( H's and T's ).

Shockable Rhythms: Pulseless Ventricular Tachycardia (pVT) & Ventricular Fibrillation (VF)

Pathophysiology : Primary cardiac events, electrolyte abnormalities (hyperkalemia), drug toxicities (tricyclic antidepressants, digoxin), or commotio cordis.

Defibrillation Energy Dosing :

First Shock : 2 J/kg (unsynchronized).

Second Shock : 4 J/kg .

Subsequent Shocks : ≥4 J/kg (up to a maximum of 10 J/kg or adult standard dose of 200 J).

Medication Timing : Resume CPR immediately after each shock for 2 minutes before re-evaluating rhythm. Administer Epinephrine 0.01 mg/kg IV/IO after the second shock. Administer Amiodarone 5 mg/kg IV/IO bolus (or Lidocaine 1 mg/kg IV/IO) after the third shock for refractory pVT/VF.

Adenosine Administration & Synchronized Cardioversion Rules
Adenosine Dosing & Administration Technique

Adenosine is the primary pharmacological treatment for stable SVT when vagal maneuvers (e.g., applying an ice bag to the upper face without occluding the nose/mouth for 15–20 seconds) fail.

First Dose : 0.1 mg/kg IV/IO rapid push (maximum initial dose 6 mg ).

Second Dose : 0.2 mg/kg IV/IO rapid push (maximum second dose 12 mg ).

Critical Administration Rule : Adenosine has an extremely short half-life (<10 seconds). It must be administered using a two-syringe rapid flush technique via a 3-way stopcock inserted as close to the patient's heart as possible (antecubital or central line). Syringe 1 contains adenosine; Syringe 2 contains a 5 to 10 mL normal saline flush . Push adenosine as a rapid IV bolus, instantly turn the stopcock, and slam the saline flush immediately behind it. Continuous 12-lead ECG monitoring must record the conversion.

Synchronized Cardioversion for Unstable Dysrhythmias

If a child with SVT or Ventricular Tachycardia with a pulse exhibits signs of instability (hypotension, poor perfusion, lethargy):

Initial Energy : 0.5 to 1 J/kg (synchronized to the R wave).

Subsequent Energy : Increase to 2 J/kg if the initial attempt is unsuccessful.

Clinical Caution : Ensure the "SYNC" mode is selected on the defibrillator to prevent delivering a shock during the vulnerable T-wave period, which could precipitate VF. Sedate if time permits, but never delay cardioversion in an unstable patient.