RESUMO
Syncope is a common symptom among older adults. Its aetiologic diagnosis is mainly clinical, but when it has an unknown origin, complementary studies are necessary. We present the experience of a single center in diagnosing Unknown Origin Syncope (UOS). METHODS: We performed a transversal retrolective study to assess the different tests done to patients studied because of USO. RESULTS: The mean age of the older group was 77.6 +/- 6.9 years. The 24-hour Hotter were abnormal in 77.9% of patients, but diagnostic in only 16.3%. Age older than 65 years was associated with a 1.9 increase (CI 95% 0.9-4) in the possibilities of having a diagnosis, while age lesser than 65 was associated with a 0.5 risk CI 95% 0.2-1.08 of having a diagnosis. The 48-hour holter showed similar results. Older age was associated with a 1.69 OR, CI 95% 0.6-4.4 to have a positive Tilt test (91% of older patients). They had mainly the vasodepressor variety of neurally-mediated syncope. (57.1% Vs 40.1%, p = 0.01). Of the 6 electrophysiologic studies performed in people older than 65 years, 3 where diagnostic (50% Vs 33.3%, p = 0.6). CONCLUSIONS: Complimentary tests in people elder than 65 years are diagnostic in a higher proportion than in their younger counterparts. Nevertheless there is a higher risk of false-positive results, so tests such as head-up tilt test should be more carefully interpreted.