Role of the Autonomic Nervous System and Vascular Endothelial Factors in the Development of Primary Arterial Hypotension in Paediatric Patients.

Background: There is a dearth and inconsistency of data on the role of the autonomic nervous system (ANS) in the development of arterial hypotension. Also, little is known about the involvement of endothelial factors in the development of this disease. The aim of the study was to investigate the role of the ANS and endothelial factors or vasoregulators in the development of primary arterial hypotension (PAH) in children.
Methods: The cardiointervalography and clino-orthostatic test results of 113 children with PAH were compared with 88 healthy children of comparable age (7-11 years). Serum endothelial factors (nitric oxide and endothelins) of all children were measured.
Results: The findings revealed that children with PAH had higher activity of the sympathetic (p<0.001) and parasympathetic (p<0.001) divisions of the ANS at the initial (resting) position of clino-orthostatic test. The activity of these divisions of the autonomic nervous system correlated with the activity of a cardiac pacemaker. The change of position from horizontal into vertical was accompanied by a rise only in sympathetic activity (p<0.001). However, there was a decline in the sympathetic nervous system (p<0.001) compared to the indices of the initial (resting) position registered in the tenth minute of the vertical position. The parasympathetic division of the ANS based on heart rate variability showed high activity in all positions of the clino-orthostatic test in the patients with PAH compared with healthy children. The activity of the parasympathetic nervous system was associated with increased synthesis of endothelial factors (nitric oxide and endothelins) in blood.
Conclusions: The inadequate response of the autonomic nervous system to the clino-orthostatic test in children with PAH is associated with disorders of both divisions of the autonomic nervous system as well as vascular endothelial factors.
(Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)