Abstract
<title>Abstract</title> <p>Background Sudden-onset vasovagal syncope (VVS) without prodromal symptoms increases the risk of falls and harm. However, the clinical characteristics of this condition remain unclear. This study aimed to compare the clinical characteristics of patients with VVS presenting with and without presyncopal symptoms. Methods We retrospectively and consecutively enrolled 221 patients with suspected syncope who underwent head-up tilt testing (VVS with no presyncope, n = 34; VVS with presyncope, n = 118; non-syncope, n = 69). Demographics, comorbidities, syncope symptoms, and examination findings were compared between the groups. Results Patients with non-presyncopal VVS accounted for 22.4% of all VVS cases. The non-presyncopal VVS group was older (median: 47 years), predominantly male (70.59%), and had a higher body mass index (median: 24.14 kg/m²) compared with the presyncopal VVS group (all P values < 0.05). The non-presyncopal VVS group had a shorter disease duration (median: 1 vs. 12 months) and higher incidence of falls (76.5% vs. 58.5%) than the presyncopal VVS group. The top three triggers for both non-presyncopal and presyncopal VVS were standing up, exercising, and fatigue. The top three most common presyncopal symptoms in patients with presyncopal VVS were dizziness (73.7%), amaurosis (52.6%), and sweating (31.3%). Conclusion Patients with non-presyncopal VVS were older and more likely to be male and had a higher body mass index, shorter course of disease, and higher incidence of falls. Future studies should investigate the mechanisms of cardiocerebral hemodynamics and neural reflex regulation in patients with non-presyncopal VVS.</p>