[Is the prognostic significance of presyncope the same as for syncope?].

Rev Esp Cardiol 2004;57(7):613-6 613 Syncope is defined as a transient loss of consciousness associated with a loss of postural tone, in which the patient recovers spontaneously without the need for electrical or pharmacological cardioversion.1,2 This symptom may have one of several causes, some of them completely benign and self-limiting, others potentially fatal. Diagnosis is primarily made on the basis of the medical history, physical examination and electrocardiogram. In addition to facilitating the diagnosis in a significant number of patients, these tools are also useful for establishing a risk profile and providing a more individualized idea of the need for more costly examinations such as the tilt-table test, electrophysiological study, or implantable loop recorder. This selective use significantly improves the diagnostic yield and cost-benefit ratio of these tests. The effectiveness of the various diagnostic tools, as well as risk stratification and the efficacy of the various therapeutic resources in patients with syncope have been the subject of numerous studies.1,2 In contrast, presyncope is poorly covered in the literature. There is little information on the definition or prognostic significance of this symptom, or on the diagnostic and therapeutic approach that should be taken when it presents. Among other reasons, this is due to a complex, often confusing or nonexistent definition in the methodology of some articles and frequent difficulty to differentiate it from other symptoms such as dizziness or even syncope. Furthermore, many studies of patients with syncope do ED I TO R I A L S