Syncope (peds)

For adult patients see syncope

Background

• Usually because of an abrupt cerebral hypoperfusion (30-50% from baseline)
• Peak age: 15-19 years of age
• In younger children, usually due to seizures, breath-holding spell or cardiac disease

Red flags

• Exercise-induced collapse
• Chest pain
• Previous cardiac surgery
• Family history of:
  • Sudden Death
  • Cardiac disease at early age
  • Unexplained deaths
  • Death due to single-vehicle accident
  • Drowning
  • SIDS

Clinical Features

• Abrupt loss of consciousness with full recovery after a short duration

Differential Diagnosis

• Seizure
• Toxicologic exposure (stimulants or depressant)
• CO poisoning
• Breath-holding spell
• Tet spell
• Cardiac disease
• Pregnancy (especially ectopic)
• Hypoglycemia

Syncope Causes

• Cardiovascular-mediated syncope
  • Dysrhythmias:
    • WPW (pre-excitation)
    • Long QT Syndrome/QT prolongation
    • Brugada Syndrome
    • Catecholaminergic polymorphic ventricular tachycardia
    • 2nd/3rd AV Block
    • Afib/aflutter
    • Vtach/torsades
    • Sick sinus syndrome
    • Arrhythmogenic right ventricular dysplasia
    • Short QT syndrome
  • Cardiovascular disease
    • Valvular Disease (AS, MS, tricuspid stenosis)
    • Aortic Dissection
    • Myocardial Infarction
    • CHF
    • Hypertrophic Cardiomyopathy
    • PE
    • Pericardial Tamponade
    • Myxoma
    • Pulmonary Hypertension
    • Pacemaker malfunction
• Neurally mediated syncope
  • Vasovagal:
    • Fear, pain, emotion, valsalva, breath-holding spell
  • Situational (associated with):
    • Coughing, micturition, defecation, vomiting, swallowing, postexercise
    • Carotid sinus stimulation
• Orthostatic hypotension-mediated syncope:
  • Volume depletion:
    • Dehydration (vomiting, diarrhea)
    • Hemorrhage, (Ectopic Pregnancy, Upper GI Bleed/Lower GI Bleeding, Abdominal Aortic Aneurysm)
    • Sepsis
  • Autonomic Dysreflexia
  • Autonomic failure due to meds
• Other serious causes
  • Stroke
  • SAH
  • TIA
  • Vertebrobasilar Insufficiency
  • Subclavian steal
  • Heat syncope
  • Hypoglycemia
  • Hyperventilation
  • Asphyxiation
  • Seizure
  • Narcolepsy
  • Psychogenic (anxiety, conversion disorder, somatic symptom disorder)
  • Toxic (drugs, carbon monoxide, etc.)

Evaluation

Workup

• ECG
• Urine pregnancy (if age/sex appropriate)

Consider based on history/symptoms

• CBC (or POC hemoglobin) & chemistry (or POC glucose)
• TSH
• Tox screen (urine or serum – based on clinical scenario)
• Bedside cardiac echocardiography
  • Cardiac hypertrophy or pericardial effusion
  • Assess the IVC for dehydration

Diagnosis

• ECG may show:
  • WPW – short PR, Delta waves, wide QRS
  • Long QT syndrome – QTc >0.450 sec
  • Hypertrophic cardiomyopathy – LVH, ST changes, T wave inversions, lateral leads needle like Q waves and absent R waves
  • Brugada syndrome – incomplete RBBB with ST elevations in V1-3
  • Arrhythmogenic right ventricular dysplasia (ARVD) – incomplete RBBB with T waves inversion in V1-3, epsilon wave is pathognomonic (up-notching of a terminal Q wave)
  • Catecholaminergic polymorphic ventricular tachycardia - May present with VT/VF due to emotional stress or a regular ECG

Management

• Directed towards reversing the cause

Disposition

• Admission if any ECG abnormality found
• Admission usually not warranted – consider admitting kids with eating disorder
• Consider discharge home with cardiology consult and strict activity restrictions if suspicion of hypertrophic cardiomyopathy in otherwise well patient with reliable caretakers

See Also

• Syncope

References

• Fischer and Cho. Pediatric Syncope: cases from the ED. Emerg Med clin N Am. Vol 28. 2010. Pp 501-516.