[Vasovagal syncope: the value of tilt-table testing in the evaluation of loss of consciousness].

Syncope, an eminently frequent syndrome, has multiple and varied causes. Its diagnosis is important in view of the poor prognosis of cardiac syncopes and also of the morbidity and discomfort associated with the other etiologies. Unfortunately, the cause eludes us in half the patients so that a clear prognosis and effective therapy can be given to only a few patients. Tilt-table testing, alone or with isoproterenol, is now considered as a noninvasive, sensitive and specific method for identifying patients predisposed to vaso-vagal syncope, a major cause of syncope of unknown origin. Tilt-table testing also helps in tracking many pathologies contributing to syncopes. In the absence of a universal treatment of vasovagal syncope, tilt-table testing has revealed itself as a contributory guide to the best possible treatment.