Pediatric emergency medicine trisk 380

vasovagal syncope will most often have a normal ECG and reassuring physical
examination.

Other Tests
The patient with syncope should be placed on a continuous cardiac monitor to
evaluate the heart rate and rhythm while in the ED. Routine use of screening
blood tests in unselected pediatric patients with syncope will have a very poor
diagnostic yield. Consider testing for hypoglycemia (via blood glucose), anemia
(hemoglobin and hematocrit), pregnancy (urine pregnancy test), and recreational
drugs (urine toxicology screen) in appropriate clinical scenarios. Check the serum
chemistry in patients suspected to have electrolyte problems such as hypokalemia
or hypocalcemia. Cardiac enzymes are not routinely recommended in pediatric
patients with syncope. However, they may be necessary in an adolescent with
chest pain, or if the clinical evaluation suggests myocarditis or structural heart
disease.
Echocardiography and Other Cardiovascular Testing
The American Heart Association recommends the use of echocardiography only
in patients with clinically suspected heart disease or exercise-induced syncope. In
the absence of a history of exercise-induced syncope, positive family history,
abnormal physical examination, or abnormal ECG, the echocardiogram does not
contribute to the routine evaluation of pediatric syncope. However, the
echocardiogram can identify underlying heart disease such as hypertrophic
cardiomyopathy, aortic stenosis, or anomalous coronary arteries. It may suggest
pulmonary hypertension if significant tricuspid regurgitation or right ventricular
enlargement is present. Indications for an echocardiogram in a patient with
syncope include known heart disease, pathologic murmur, evidence of chamber
hypertrophy on ECG or chest radiograph, repolarization abnormalities with strain
or ischemia, ventricular ectopy or concern for myocarditis, cardiomyopathy, or
pulmonary hypertension.
Ambulatory ECG (Holter) monitoring may be useful if the screening ECG is
normal but the history still suggests an arrhythmia as source of syncope, if there

is exertional syncope, or if the relationship of a nonspecific ECG finding to
symptoms is unclear. An event recorder may be more practical because patients
are able to keep the monitor for a month and activate it at the time of their
symptoms. The stress test may help in eliciting changes in QT intervals in
patients with LQTS or arrhythmias in those with catecholaminergic polymorphic
ventricular tachycardia (CPVT), but should be ordered by a cardiologist. Exercise


stress testing may be helpful in the diagnosis of channelopathies, such as LQTS
and CPVT, which have adrenergically mediated arrhythmias.
The head-upright tilt table test (HUTT) may be used to provoke a hypotensive
episode that mimics the patient’s symptoms. However, it has low sensitivity, and
current guidelines recommend it only in cases when the diagnosis of vasovagal
syncope is truly unclear. Pediatric patients with episodes of vasovagal syncope
may exhibit convulsive movements during loss of consciousness that mimic
epileptic seizures; HUTT may help in differentiating children with a primary
seizure disorder. A combined cardiology and neurology evaluation may be
warranted in patients with syncope and seizure-like activity. Additional
indications for use of HUTT are recurrent syncope or exertional syncope in which
heart disease has been ruled out, or recurrent syncopal episodes thought to be due
to conversion disorder.
Neurologic Testing
Neuroimaging is rarely required for a typical patient with syncope and the
diagnostic yield is likely to be low. The only indication for neuroimaging is for a
patient with focal neurologic deficits or persistently altered mental status in
whom it is necessary to rule out significant intracranial injury or cerebrovascular
accident. An electroencephalogram (EEG) may be performed on an outpatient
basis if clinical features suggest a seizure and the patient has returned to a
baseline neurologic status. However, it is important to remember that a normal
EEG does not rule out epilepsy.

TREATMENT
Most children with syncope can be managed on an outpatient basis. Patients with
vasovagal syncope and their families will need reassurance and education about
the benign nature of the condition. They should be taught how to recognize
prodromal symptoms and avoid precipitating factors such as dehydration,
standing for prolonged periods, hot crowded environments, and diuretic intake.
Maneuvers to prevent venous pooling (such as keeping the knees slightly bent
when standing for a long time, isometric contraction of extremity muscles, toe
raises, folding of the arms, and crossing of the legs) or even assuming a seated or
supine position may help. Patients should be encouraged to increase their oral
intake of water (up to 3 L per day in an adolescent), to add salty snacks to their
diet, and to avoid consuming caffeinated beverages. If increased fluid and salt
intake are not helpful, pharmacotherapy may be considered in patients with
recurrent syncope.


TABLE 76.3
CONDITIONS THAT MAY REQUIRE HOSPITALIZATION IN
PEDIATRIC SYNCOPE
Abnormal cardiovascular examination and cardiovascular disease
Drug-related syncope
Attempted suicide
Neurologic
Persistently altered mental status
Focal neurologic deficits
Recurrent seizures
Recurrent hypoglycemia
Orthostatic hypotension resistant to fluid therapy
Patients who require CPR

CPR, cardiopulmonary resuscitation.

A variety of different medications have been tried in pediatric patients with
recurrent syncope. Of these, midodrine, an α-adrenergic agonist, has shown some
of the most beneficial results in reducing symptom recurrence with few side
effects. Fludrocortisone, a mineralocorticoid, has also been used; however, its
effectiveness is uncertain in pediatric patients with orthostatic hypotension
associated with syncope. Since symptoms of depression or anxiety are common in
patients with recurrent syncope, management of potential mood disorders may be
beneficial. The treatment of POTS is challenging, and no one pharmacologic or
nonpharmacologic approach has been consistently successful. Recommendations
include education, hydration with clear, no caffeinated beverages, increased salt
intake, elevation of the head of the bed by 10 to 15 cm, and a gradual
reconditioning exercise program spaced over 3 months.
Patients with recurrent syncopal symptoms who do not improve with
conservative measures and pharmacotherapy, as well as those with a suspected
cardiac cause for syncope, should be referred to a cardiologist for further
management. Some situations may warrant hospital admission or observation of a
child with syncope ( Table 76.3 ), especially those involving persistent
cardiovascular abnormalities or neurologic deficits.
For congenital LQTSs, the mainstay of therapy is the use of a long-acting beta
blocker. Because syncope in these patients is adrenergically mediated, they are
restricted from athletic activity. The use of an implantable cardioverter-


defibrillator (ICD) is considered in a subgroup of patients felt to be at high risk
for sudden death, such as those with symptoms before puberty, very long QT
intervals (>500 msec), and those with recurrent syncope. The use of an ICD is
also required in patients with hypertrophic cardiomyopathy and Brugada
syndrome. Adult survivors of congenital heart disease should be cared for by

health providers knowledgeable in the anatomy, repair, and management of these
conditions.

SUMMARY POINTS
Syncope is a common condition in children and is usually benign. Common
causes for syncope include vasovagal syncope, breath-holding spells, and
orthostatic intolerance. Life-threatening causes are usually cardiac in etiology. A
comprehensive medical and family history, a thorough physical examination, and
a 12-lead ECG will help identify most patients with life-threatening causes of
syncope. Routine blood testing and imaging are unnecessary. Since recurrence is
common, education and reassurance are important.
Suggested Readings and Key References
Goldenberg I, Moss AJ, Peterson DR, et al. Risk factors for aborted cardiac arrest
and sudden cardiac death in children with the congenital long-QT syndrome.
Circulation 2008;117:2184–2191.
Morrow W, Berger S, Jenkins K, et al. Pediatric sudden cardiac arrest. Pediatrics
2012;129:e1094–e1102.
Roden DM. Long-QT syndrome. N Eng J Med 2008;358:169–176.
Sheldon RS, Grubb BP 2nd, Olshansky B, et al. 2015 Heart Rhythm Society
expert consensus statement on the diagnosis and treatment of postural
tachycardia syndrome, inappropriate sinus tachycardia, and vasovagal syncope.
Heart Rhythm 2015;12:e41–e63.
Shen WK, Sheldon RS, Benditt DG, et al. 2017 ACC/AHA/HRS guideline for the
evaluation and management of patients with syncope: a report of the American
College of Cardiology/American Heart Association task force on clinical
practice guidelines and the heart rhythm society. Circulation 2017;136(5):e60–
e122.