J wave pattern in unexplained syncope

J wave pattern (JWP), characterized by J-point elevation in the anterolateral or inferior leads of the 12-lead electrocardiogram, has been associated with increased risk for idiopathic ventricular fibrillation and mortality. However, its prevalence in syncope of different etiologies is unknown and was evaluated in this study. The study sample comprised 170 consecutive patients with vasovagal syncope or syncope that remained unexplained after complete work-up. JWP in inferior leads and with a horizontal/descending ST-segment is more frequently found in subjects with unexplained syncope than in subjects with vasovagal syncope. This finding may be linked with worse prognosis of unexplained syncope.