[Syncope in children].

Syncope is a very common problem during childhood presenting to emergency departments. It generates a great deal of anxiety among children and their parents because of the fear that syncope are at risk for sudden death. Neurocardiogenic (vaso-vagal) syncope are the most common, while cardiac type are rare. The vaso-vagal syncope are secondary to irregularities in an autonomic reflex resulting in an abnormal relaxation of the blood vessels. This is non-life threatening form of syncope in differ cardiac type that can be very dangerous. In cardiac syncope causes can be secondary to obstruction to blood flow (Tetralogy of Fallot, cardiomyopathies, aortic stenosis), heart rhythm abnormalities (WPW, L-QTS, A-V block) as well as ischemic heart disease secondary to an anomalous coronary artery. The cardiac syncope are rare (6%) but the most inconvenient because they can be life-threatening.