SYNCOPE IN THE PEDIATRIC PATIENT: The Cardiologist's Perspective

Syncope is the transient loss of consciousness and postural tone that results from inadequate cerebral perfusion. The most common prodromal symptom that children and adolescents with syncope report is dizziness. Dizziness is a nonspecific symptom that generally requires elaboration by the patient for the physician to be sure exactly what the patient means. The description of the feeling is critical in distinguishing whether the sensation is a result of vertigo, disequilibrium, lightheadedness, or presyncope (Table 1). 12 Although the differential diagnoses of these entities overlap, certain specific conditions are common to each. Almost by definition, all are conditions of older children who are capable of articulating the abnormal sensation they perceive. Children fewer than 6 years old may present with nausea, vomiting, ataxia, or frank syncope. Presyncope is the feeling that one is "about to pass out." These patients feel as if they are going to lose consciousness but do not. Presyncope may or may not reflect the same pathophysiology as true syncope. The approach to presyncope, however, is essentially the same as that for syncope. Dizziness must be considered a change in mental status and taken seriously. It may indicate potentially severe underlying CNS dysfunction. Dizziness must be better defined to also distinguish vertigo from lightheadedness. 12 The principal distinction is the description of motion; swaying, whirling, and spinning are characteristic of vertigo. Lightheadedness often accompanies hyperventilation and is therefore frequently associated with psychological distress, including anxiety, depression, and panic attacks. The last of the "dizzy" feelings is disequilibrium. Disequilibrium refers to "balance problems" without vertigo. The characteristic historical feature is difficulty ambulating. A fairly rare complaint among children, disequilibrium in the young is most often caused by vestibular dysfunction or ataxia.