Syncope (peds)

Background

Syncope : abrupt loss of consciousness with full recovery after a short duration. Usually because of an abrupt cerebral hypo-perfusion (30-50% from baseline) – due to brief cardiac output decrease, impaired venous return, a cardiac arrhythmia, or transient hypotension. Peak age – 15-19 years of age, equal sex distribution. In the 6 year old – usually due to seizures, breath holding or cardiac issue. In total only 3% of Peds ED visits. Most are benign; 60-80% are vaso-vagal. Cardiac causes constitute 2-6%.

Clinical Features

History is key! Ask as many witnesses as possible. Pre syncope? Any jerking or tonic-clonic movement (before/during/after LOC)? Exertion? SOB? Dehydration? Heat? Last meal? Aura? Amnesia? Nausea? Diaphoresis? Menstruating? Previous cardiac surgery or procedure? Previous diagnosis of Kawasaki? Medications or over-the-counter or illicit drugs?

Red flags:

1. Exercise-induced collapse
2. Chest pain
3. Previous cardiac surgery
4. Family history of:
   1. Sudden Death
   2. Cardiac disease at early age? or Pacemaker?
   3. Drowning
   4. SIDS

Diagnosis

1. Orthostatic vital signs
2. Full neurological examination (focus on Fundi, Cranial Nerves, Gait, Romberg, DTR’s and Cereberllar testing)
3. Any stigmata of Endocrine disorder? Marfanoid habitus? Neurological disorder (e.g. café-au-lait spots)?
4. Signs of an eating disorder?

Work-Up

1. ECG – looking for:
   1. WPW – short PR, Delta waves, wide QRS
   2. Long QT syndrome – QTc >0.450 sec
   3. Hypertrophic Cardiomyopathy – LVH, ST changes, T wave inversions, lateral leads needle like Q waves and absent R waves
   4. Bruagada syndrome – refer to Brugada (incomplete RBBB with ST elevations in V1-3)
   5. Arrhythmogenic right ventricular dysplasia (ARVD) – incomplete RBBB with T waves inversion in V1-3. Epsilon wave is pathognemonic (up-notching of a terminal Q wave)

1. Tox screen (urine or serum – based on clinical scenario)
2. Beta-HCG
3. Serum extended electrolytes, CBC, TSH
4. Bedside cardiac ultrasound
   1. Cardiac hypertrophy or pericardial effusion
   2. Assess the IVC for dehydration

DDx

1. Toxicological (stimulants or depressant)
2. CO poisoning
3. Breath-holding spell
4. Tet-spell

Treatment

Directed towards reversing the cause

Disposition

Cardiology consult +/- admission if any ECG abnormality found Admission usually not warranted – consider admitting kids with eating disorder

See Also

Syncope

Source

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