Syncope, also described as “fainting” or “blackouts,” is defined as a transient period of unconsciousness that is brief and abrupt in onset and resolves spontaneously to a restored level of function. It is a symptom rather than a diagnosis and does not necessarily indicate disease. The causes of syncope in children are heterogeneous and are most often benign in nature. Nevertheless, syncopal events can cause significant distress among patients, families, school personnel, and physicians. Since it is a relatively common occurrence in childhood, hospitalists should have a practical approach to the evaluation of pediatric syncope, focusing on identification of those rare individuals who are at risk for serious underlying disease.
Patients experience syncope when inadequate cerebral perfusion results in a transient loss of consciousness and postural tone. Presyncope describes a similar event without full loss of consciousness. Girls present more commonly for the evaluation of syncope than boys, with a peak incidence between 13 and 19 years of age.1 Most syncope in pediatric patients is autonomic in origin, isolated, and benign. In fact, the risk of sudden death among pediatric patients with prior syncopal events has been found to be equivalent to the risk of sudden death in the general population.2
History and physical examination can provide valuable clues to the probable cause of a syncopal episode and may curtail or circumvent the need for further diagnostic evaluation. Important historical features of a patient presenting with syncope are included in Table 37-1. Recent circumstances and those immediately preceding the syncopal event should be thoroughly explored. Because patients are often unable to provide details of an episode, witnesses to the event are important. Past medical history, especially with regard to previous syncopal episodes, cardiac or neurologic conditions, and medications, should always be obtained. Specific inquiries about family history should include sudden death, syncope, sudden infant death syndrome, congenital heart disease, seizures, and congenital deafness (associated with a genetic disorder that includes Long-QT). A patient’s baseline level of health should also be ascertained, including any overall changes in energy level, exercise tolerance, nutritional status, or the development of new respiratory symptoms, chest pain, or tightness and any emotional stressors.
TABLE 37-1Directed Patient History for Syncope |Favorite Table|Download (.pdf) TABLE 37-1 Directed Patient History for Syncope
Environmental factors/triggers (posture, temperature, hydration status, fatigue, illness)
Frequency and duration of syncope
Level of activity just prior to syncopal episode (exertion*)
Elements of history from any witnesses (cyanosis*)
Medication history (potential for lengthening QTc or arryhthmogenic*)
Baseline level of health
Generalized symptoms of concern (fatigue, cough, weight loss, shortness of breath, chest pain*)
Personal or family history of any of the following conditions*
congenital heart disease
sudden cardiac death
sensorineural hearing loss
other familial heart diseases