Postural Tachycardia Syndrome in Children and Adolescents: Pathophysiology and Clinical Management.

Guozhen Chen,Hongfang Jin,Yaqian Huang,Junbao Du

doi:10.3389/fped.2020.00474

Abstract

Postural tachycardia syndrome (POTS), characterized by chronic (≥6 months) orthostatic intolerance symptoms with a sustained and excessive heart rate increase while standing without postural hypotension, is common in children and adolescents. Despite the unclear pathogenesis of POTS, the present opinion is that POTS is a heterogeneous and multifactorial disorder that includes altered central blood volume, abnormal autonomic reflexes, “hyperadrenergic” status, damaged skeletal muscle pump activity, abnormal local vascular tension and vasoactive factor release, mast cell activation, iron insufficiency, and autoimmune dysfunction. A number of pediatric POTS patients are affected by more than one of these pathophysiological mechanisms. Therefore, individualized treatment strategies are initiated in the management of POTS, including basal non-pharmacological approaches (e.g., health education, the avoidance of triggers, exercise, or supplementation with water and salt) and special pharmacological therapies (e.g., oral rehydration salts, midodrine hydrochloride, and metoprolol). As such, the recent progress in the pathogenesis, management strategies, and therapeutic response predictors of pediatric POTS are reviewed here.

Highlights

Postural tachycardia syndrome (POTS) is one of the common forms of chronic orthostatic intolerance (OI), and most of the cases have presyncope symptoms accompanied by inappropriate sinus tachycardia with normal blood pressure in an upright position [1, 2]
To further explore the mechanism for vascular tension dysfunction, some studies have been designed, and the results show that bioactive gaseous regulatory molecules and vasoactive peptides are involved in the development of abnormal partial vascular tension and impaired endothelial cell function in children and adolescents with POTS [5, 35, 59,60,61,62,63]
The results suggest that the increased endogenous IMD or C-type natriuretic peptide (CNP) levels with similar features of vascular dilation represent the endogenous molecules involved in the development of POTS

Summary

Introduction

Postural tachycardia syndrome (POTS) is one of the common forms of chronic (at least 6 months) orthostatic intolerance (OI), and most of the cases have presyncope symptoms accompanied by inappropriate sinus tachycardia with normal blood pressure in an upright position [1, 2]. Zhang et al [38] reported that the plasma norepinephrine level in the upright position was positively associated with the severity of symptoms and the HR increase in the HUTT in pediatric POTS patients, and they speculated that the orthostatic norepinephrine increase might be due to the decreased vasoconstriction mediated by the baroreflex upon standing.

Results

Conclusion