Neurally mediated syncope: Is it really an endothelial dysfunction?

Area of Science:

• Cardiology
• Pediatrics
• Vascular Biology

Background:

• Syncope is a frequent condition in pediatric and adolescent populations.
• Neurally mediated syncope represents the most common type of syncope.
• The precise pathophysiology of neurally mediated syncope remains incompletely understood despite existing research.

Purpose of the Study:

• To investigate endothelial function in children and adolescents with unexplained syncope.
• To compare endothelial markers between patients with neurally mediated syncope and healthy controls.

Main Methods:

• A cross-sectional study involving 27 patients (5-20 years) with unexplained syncope and 30 healthy controls.
• Assessment of endothelial function included flow-mediated dilation (FMD), intima-media thickness (IMT), and levels of VCAM, ICAM, E-selectin, epinephrine, and norepinephrine.
• Statistical analysis using SPSS 20 with independent sample t-tests to compare group means.

Main Results:

• Patients with syncope exhibited significantly higher mean FMD (p=0.028) compared to controls.
• Significantly elevated levels of intercellular adhesion molecule (ICAM) (p=0.02) and vascular cell adhesion molecule (VCAM) (p=0.008) were found in the syncope group.
• Mean epinephrine levels were significantly lower (p=0.01) in the syncope group, while norepinephrine showed a non-significant decrease.

Conclusions:

• The findings suggest a potential role for endothelial dysfunction or augmented endothelial function in neurally mediated syncope.
• These vascular alterations may contribute to the pathophysiology of syncope in pediatric patients.