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Flow-mediated vasodilation and endothelium function in children with postural orthostatic tachycardia syndrome

Ying Liao1, Stella Chen, Xueqin Liu

  • 1Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China.

The American Journal of Cardiology
|July 21, 2010
PubMed

Insights

Children with postural orthostatic tachycardia syndrome (POTS) exhibit enhanced flow-mediated dilation (FMD) and elevated nitric oxide (NO) and NO synthase (NOS) levels. These findings suggest abnormal vascular endothelium function contributes to POTS in pediatric patients.

Area of Science:

  • Cardiology
  • Pediatrics
  • Vascular Biology

Background:

  • Postural orthostatic tachycardia syndrome (POTS) affects children, impacting autonomic nervous system function.
  • Endothelial dysfunction is implicated in various cardiovascular conditions, but its role in pediatric POTS is not fully understood.

Purpose of the Study:

  • To investigate flow-mediated vasodilation (FMD) and endothelial function in children diagnosed with POTS.
  • To compare FMD, plasma nitric oxide (NO), and NO synthase (NOS) activity between children with POTS and healthy controls.

Main Methods:

  • Utilized color Doppler vascular ultrasound to measure brachial artery FMD in 46 children with POTS and 20 healthy controls.
  • Quantified plasma NO concentrations and NOS activity in both groups.
  • Employed independent t-tests for statistical comparison between groups.

Main Results:

  • Children with POTS demonstrated significantly higher FMD (10.8% vs. 5.7%) compared to controls (p < 0.01).
  • Plasma NO levels (74 vs. 62 µmol/L) and NOS activity (21 vs. 15 U/mL) were significantly elevated in the POTS group (p < 0.01).
  • A significant positive correlation was observed between FMD and NOS activity.

Conclusions:

  • Augmented FMD and altered vascular endothelium function, characterized by increased NO and NOS, are associated with POTS in children.
  • These findings highlight the potential role of endothelial dysfunction in the pathophysiology of pediatric POTS.

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