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Syncope is a presenting symptom for 1% to 3% of all pediatric emergency visits. It is more common in adolescents than younger children. Up to 50% of adolescents experience at least one syncopal episode which is usually transient and self-limited, but can be a symptom of serious cardiac disease.
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Sudden, unexpected death in children comprises 2.3% of all pediatric deaths, of which sudden cardiac death makes up about one-third. The risk of sudden cardiac death is greater in patients with congenital or acquired heart disease, even those that have undergone corrective surgery. Except for trauma, sudden cardiac death is the most common cause of sports-related deaths. Hypertrophic cardiomyopathy and congenital artery anomalies are the most common cause of sudden cardiac death in adolescents without known cardiac disease. Other causes of sudden cardiac death in children include myocarditis, congenital heart disease, and conduction disturbances.
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Syncope is the sudden onset of falling accompanied by a brief episode of loss of consciousness. Involuntary motor movements may occur with all types of syncopal episodes but are most common with seizures. Table 78-1 lists the most common causes of syncope by category.
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Neurally mediated syncope is the most common cause in children. This type of syncope typically lasts <1 minute and is preceded by sensations of nausea, warmth, or light-headedness with a gradual visual grayout. Cardiac syncope occurs when there is an interruption of cardiac output from an intrinsic problem such as tachydysrhythmia, bradydysrhythmia, outflow obstruction, and myocardial dysfunction. Syncope resulting from cardiac causes usually begins and ends abruptly and may be associated with chest pain, palpitations, or shortness of breath. Risk ...