Aetiologic and clinical characteristics of syncope in Chinese children

This study aimed to improve diagnostic efficacy of syncope in children by analyzing the aetiology and clinical characteristics of syncope in Chinese children.

We retrospectively analyzed the causes of syncope and diagnostic workup in 154 consecutive children seen in the Department of Pediatrics, Peking University First Hospital, China, because of a syncope-related event.

In all patients with transient loss of consciousness (TLOC), there were 136 (88.31%) patients attributing to syncope, and 18 (11.69%) belonging to nonsyncopal cases. Neurally mediated syncope (NMS) was the most common cause of syncope (99 cases; 64.3%), with cardiac causes ranking second (10 cases; 6.5%). Other nonsyncopal causes included psychiatric problems and neurological and metabolic disorders. In 25 cases (16.2%), the cause was uncertain. Cases of NMS often had clear inducement of syncope and prodromes. Children with cardiac syncope often had a history of cardiac disease, were often younger than those with NMS, and showed exercise-related syncope, syncope spells in any body position or at an early age, or sudden death in family members but no prodromes. Neurological disorder was suspected in cases of TLOC with seizures, TLOC spells in any position, postictal phase of disorientation or abnormal neurological signs. A metabolic cause is suspected with a history of metabolic disease, prolonged anger, or violent vomiting and diarrhoea. Children with psychiatric disorders were adolescent girls, with prolonged TLOC spells, who had more frequent TLOC. Although many tests were used in diagnosis, most were not goal directed. Now, electrocardiography is recommended in almost all children with syncope. Neurological testing, including electroencephalography and computed tomography were rarely helpful unless with evidence of neurological signs and symptoms. Head-up tilt test (HUTT) was most useful in children with recurrent syncope in whom heart disease was not suspected.

NMS was the most common cause of syncope. We recommended HUTT as the important basis of the TLOC workup.