Heart rate variability characteristics in children with cardiac syncope
Summary. The imbalance of autonomic nervous system is one of the main pathophysiological mechanism of syncope. At the heart of their development of any genesis is to reduce systemic blood pressure, causing a decrease in total cerebral blood flow current and leads to loss of consciousness. It is proved that the sudden cessation of cerebral blood flow on 6–8 s causes loss of consciousness. The aim of the study – to learn the features of time and frequency domain parameters of heart rate variability in children with cardiac syncope. Materials and Methods. 19 patients with cardiac syncope and 41 healthy children aged 8–17 years were examined. The European Society of Cardiology Guidelines (2018) was used in the diagnosis of cardiac syncope. Time (SDANN, RMSSD, pNN50) and frequency domain (TP, VLF, LF, HF, LF/HF) parameters of heart rate variability were studied using a 3-Channel Digital ECG Holter Recorder SDM3 (Ukraine). Serum 25(OH)D level was determined by colorimetric enzyme-linked immunosorbent assay using the Monobind test system (USA). Results. Heart rate variability parameters SDANN, RMSSD, pNN50 and LF/HF did not differ in patients of the main and control groups (p>0.05). However, there were high values of TP (12751.64±2060.01) ms2, (5482.44±396.87) ms2; p = 0.00005), VLF (6615.17±819.89) ms2; (3906.29±269.09) ms2; p = 0.003), LF (5194.583±797.16) ms2; (2379.22±172.60) ms2; p = 0.0015), and HF (4049.14±774.07) ms2; (2446.54±316.16) ms2; p = 0.028) in patients with cardiac syncope compared with healthy children. A direct correlation between the vitamin 25(OH)D level and pNN50 (r = 0.49; p = 0.04) was found which indicates the possible influence of vitamin D deficiency to the development of dysautonomia in children with syncope. The obtained results can be useful for using of heart rate variability analysis as independent criteria to monitoring of a patient with cardiac syncope and assessment of treatment effectiveness. Conclusions. The functional state of autonomic nervous system in children with cardiac syncope is characterized by a balanced autonomic influence on cardiac activity. At the same time stress of regulatory systems on the background of increased activity of sympathetic and parasympathetic links of regulation, and a high level of central mechanisms activity of heart rate regulation are observed
cardiac syncope, heart rate variability, autonomic nervous system, children
https://doi.org/10.11603/bmbr.2706-6290.2021.3.12217[1] Moya A, Sutton R, Ammirati F, Blanc JJ, Brignole M, Dahm JB, et al. Guidelines for the diagnosis and management of syncope (version 2009). Eur Heart J. 2009;30(21): 2631-71. Available from: https://doi.org/10.1093/eurheartj/ehp298.
[2] Grossman SA, Badireddy M. Syncope. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK442006/.
[3] Márquez MF, Gomez-Flores JR, Gonzalez-Hermosillo JA, Ruiz-Siller TJ, Cardenas M. Role of the sympathetic nervous system in vasovagal syncope and rationale for beta-blockers and norepinephrine transporter inhibitors. Medwave. 2016;16(Suppl.4): e6824.
[4] Shim SH, Park SY, Moon SN, Oh JH, Lee JY, Kim HH, et al. Baseline heart rate variability in children and adolescents with vasovagal syncope. Korean J Pediatr. 2014;57(4): 193-8.
[5] Akizuki H, Hashiguchi N. Heart rate variability in patients presenting with neurally mediated syncope in an emergency department. Am J Emerg Med. 2020;38(2): 211-6. 10.1016/j.ajem.2019.02.005.
[6] Kovalchuk T, Boyarchuk O, Pavlyshyn H, Balatska N, Luchyshyn N. Analysis of heart rate variability in paediatric patients with vasovagal syncope. Pediatria Polska – Polish Journal of Paediatrics. 2019;94(6): 357-367. https://doi.org/10.5114/polp.2019.92965.
[7] Zhixiang Y, Cheng W, Jibing X, Bisheng G, Ming X, Deyu L. Ambulatory blood pressure monitoring in children suffering from orthostatic hypertension. Biomed Eng Online. 2018;17(1): 129. Available from: https://doi.org/10.1186/s12938-018-0530-4.
[8] Brignole M, Moya A, de Lange FJ, Deharo JC, Elliott PM, Fanciulli A, et al. 2018 ESC Guidelines for the diagnosis and management of syncope. Eur Heart J. 2018;39(21): 1883-1948. Available from: https://doi.org/10.1093/eurheartj/ehy037.
[9] Tanaka H, Fujita Y, Takenaka Y, Kajiwara S, Masutani S, Ishizaki Y, et al. Japanese clinical guidelines for juvenile orthostatic dysregulation version 1. Pediatr Int. 2009;51(1): 169-79. Available from: https://doi.org/10.1111/j.1442-200X.2008.02783.x.
[10] Berezhny`j VV, Romankevych IV. [Application of determination of heart rate variability in children]. Sovremennaya pediatriya. 2015;1: 87-91. Ukrainian.
[11] Parati G, Stergiou G, O'Brien E, Asmar R, Beilin L, Bilo G, et al. European Society of Hypertension practice guidelines for ambulatory blood pressure monitoring. J Hypertens. 2014;32(7): 1359-66. Available from: https://doi.org/10.1097/HJH.0000000000000221.
[12] Koval`chuk TA, Boyarchuk OR. [The role of vitamin D deficiency in the genesis of vasovagal syncope in children]. International Journal of Endocrinology. 2020;6(2): 231-236. Ukrainian.
[13] Zhang Q, Sun Y, Zhang C, Qi J, Du J. Vitamin D deficiency and vasovagal syncope in children and adolescents. Front Pediatr. 2021;9: 575923. Available from: https://doi.org/10.3389/fped.2021.575923.
[14] Marushko YuV, Gyshhak TV. Systemic mechanisms of adaptation. Stress in children. [Системні механізми адаптації. Стрес у дітей] Kyiv; 2014. Ukrainian.
[15] Akcaboy M, Atalay S, Ucar T, Tutar E. Heart rate variability during asymptomatic periods in children with recurrent neurocardiogenic syncope. Turk J Pediatr. 2011;53(1): 59-66.