[Dynamic electrocardiogram and syncope: a couple in real crisis?].

Holter monitoring is still considered as a class I diagnostic tool for the assessment of syncope. This is due to poor yield of the diagnostic techniques available until the middle 1980s. However, considering the impressive progress made in the differential diagnosis of this clinical condition, such widespread use is no longer justified. The limitations of Holter monitoring are highlighted by its costs per diagnosis and, in particular, by comparison with other maneuvers, such as the head-up tilt test or the carotid sinus massage, which have a higher positive predictive value for patients with syncope of unknown origin. The diagnostic yield of Holter monitoring has to be considered particularly low among patients free from structural heart disease in whom the risk of arrhythmic syncope is extremely low.