title: Recent advances in the understanding of the mechanisms underlying postural tachycardia syndrome in children: practical implications for treatment.
abstract: Postural tachycardia syndrome is defined by a heart rate increment of 40 beats/minute (bpm) (or a heart rate that exceeds 125 bpm) within 10 minutes of change from the supine position to an upright position in the absence of obvious orthostatic hypotension. There are multiple pathophysiological mechanisms that underlie postural tachycardia syndrome, including peripheral denervation, β-receptor supersensitivity, hypovolaemia, and impaired muscle pump. Some children afflicted with postural orthostatic tachycardia syndrome and hypovolaemic dysregulation have been found to have perturbed renin-angiotensin-aldosterone profile, disturbed vascular endothelial function, and abnormal vasodilation. The hyperadrenergic state in some postural tachycardia syndrome patients is likely a driver for orthostatic tachycardia. Other mechanisms include the presence of treatable autonomic neuropathies. An understanding of these pathophysiological mechanisms might be helpful for the effective treatment of postural tachycardia syndrome.
authors.affiliation: Department of Pediatrics,Peking University First Hospital,Beijing,P. R. China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Department of Pediatrics,Peking University First Hospital,Beijing,P. R. China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Pediatrics,Peking University First Hospital,Beijing,P. R. China.
authors.forename: Junbao
authors.initials: J
authors.lastname: Du
mesh_terms: D001341:Autonomic Nervous System / Q000503:physiopathology*; D002648:Child; D019468:Disease Management; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D054972:Postural Orthostatic Tachycardia Syndrome / Q000503:physiopathology* / Q000628:therapy; D011187:Posture / Q000502:physiology; D018667:Tilt-Table Test
keywords: Postural tachycardia syndrome; blood volume; children; heart; vasoactive peptides; vessel