RESUMEN
BACKGROUND: Little is known about the clinical characteristics of patients with situational syncope such as defecation syncope (DS) or micturition syncope (MS) compared with those with common vasovagal syncope (VVS). METHODS: Among 680 consecutive patients, who underwent a head-up tilt test between January 2006 and November 2010, 282 patients (40.4±16.7 years; 48.6% men) diagnosed as DS (n = 38), MS (n = 38), or common VVS (n = 208) were included. RESULTS: Ages at diagnosis (38.7±17.3 vs 48.3±14.1 vs 42.0±13.8, P = 0.004) and the first syncope (33.7±18.4 vs 44.5±15.3 vs 37.5±14.6, P = 0.002) were significantly less in patients with common VVS than those with DS or MS, respectively. The patients with MS were more likely to be men (73.7%, P = 0.036), whereas patients with DS were more commonly women (73.7%). No sexual preference was observed in patients with common VVS. Body mass index was significantly lower (P = 0.047) and syncopal episodes were more recurrent (P = 0.049) in patients with common VVS than those with DS or MS. The frequency of drinking alcoholbefore syncope was significantly higher in patients with MS (39.5%, P < 0.001). CONCLUSIONS: DS tended to occur in older women, whereas MS tended to occur in middle-aged men and drinking alcohol was an important precipitating factor for MS. However, common VVS was observed more in a thin and young population, which was more recurrent compared with those situational syncopes.