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The autonomic nervous system dysregulation in response to orthostatic stress in children with neurocardiogenic syncope

Published online by Cambridge University Press:  22 March 2010

Burcu Topcu
Affiliation:
Faculty of Medicine, Department of Pediatrics, Marmara University, Kadıköy/Istanbul, Turkey
Figen Akalın*
Affiliation:
Faculty of Medicine, Subdepartmet of Pediatric Cardiology, Marmara University, Kadıköy/Istanbul, Turkey
*
Correspondence to: Dr Figen Akalın, Bahariye. Safa sokak 19/11, 81310, Kadıköy/Istanbul. Tel: +90(216)3473675; Fax: +44(0)2163250323; E-mail: figenakalin@gmail.com

Abstract

Neurocardiogenic syncope is a common disorder, which is considered as a benign condition. However, sudden loss of conscience and muscle tone causes anxiety among the family members due to its similarity to sudden death. Autonomic nervous system dysregulation is thought to be responsible in the aetiology. Heart rate variability is used for assessment of autonomic nervous system.

We evaluated 24 children between 6 and 18 years (mean plus or minus standard deviation is equal to 12.5 plus or minus 3.28, with neurocardiogenic syncope and 10 healthy controls, mean plus or minus standard deviation is equal to 12.48 plus or minus 3.27) by using 24 hour Holter monitorisation and head-up tilt test. Heart rate variability analysis was performed using the Holter recordings obtained both during head-up tilt test and throughout the day.

Our results revealed that, there is no significant difference between the study and the control groups in terms of the mean heart rate and all indices of the heart rate variability (p > 0.05). However, during the first 5 minutes of the head-up tilt test, standard deviation of all RR intervals and root mean square of successive differences were significantly lower in the syncope group compared with the control group, 42.17 plus or minus 12.56 versus 60.10 plus or minus 33.10 and 21.26 plus or minus 8.87 versus 36.80 plus or minus 31.03; p-values 0.02 and 0.03, respectively.

In conclusion; autonomic functions in children with neurocardiogenic syncope are similar to healthy children. However, sympathetic hyperactivation occurs during the early phase of orthostatic stress in children with neurocardiogenic syncope comparing to healthy controls. Parasympathetic innervation is not sufficient in compensation of this sympathetic hyperactivation. Management strategy in neurocardiogenic syncope should be based on these pathophysiologic mechanisms.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 2010

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References

1.Johnsrude, CL. Current approach to pediatric syncope. Pediatr Cardiol 2000; 21: 522531.CrossRefGoogle ScholarPubMed
2.Chen-Scarabelli, C, Scarabelli, TM. Neurocardiogenic syncope. BMJ 2004; 329: 336341.CrossRefGoogle ScholarPubMed
3.McLeod, KA. Syncope in childhood. Arch Dis Child 2003; 88: 350353.CrossRefGoogle ScholarPubMed
4.Brignole, M, Alboni, P, Benditt, D, et al. Guidelines on management (diagnosis and treatment) of syncope. Eur Heart J 2001; 22: 12561306.CrossRefGoogle ScholarPubMed
5.Lewis, DA, Dhala, A. Syncope in pediatric patient. The cardiologist’s perspective. Pediatr Clin North Am 1999; 46: 205219.CrossRefGoogle ScholarPubMed
6.Alehan, D, Ayabakan, C, Özer, S. Heart rate variability and autonomic nervous system changes in children with vasovagal syncope. Pacing Clin Electrophysiol 2002; 25: 13311338.CrossRefGoogle ScholarPubMed
7.Evrengul, H, Tavli, V, Evrengul, H, Tavli, T, Dursunoglu, D. Spectral and time-domain analyses of heart-rate variability during head-upright tilt-table testing in children with neurally mediated syncope. Pediatr Cardiol 2006; 27: 670678.CrossRefGoogle ScholarPubMed
8.Morillo, CA, Klein, GJ, Jones, DL, Yee, R. Time and frequency domain analyses of heart rate variability during orthostatic stress in patients with neurally mediated syncope. Am J Cardiol 1994; 74: 12581262.CrossRefGoogle ScholarPubMed
9.Sehra, R, Hubbard, JE, Straka, SP, Fineberg, NS, Engelstein, ED, Zipes, DP. Autonomic changes and heart rate variability in children with neurocardiac syncope. Pediatr Cardiol 1999; 20: 242247.CrossRefGoogle ScholarPubMed
10.Lagi, A, Tamburini, C, Cipriani, M, Fattorini, L. Vagal control of heart rate variability in vasovagal syncope: studies based on 24-h electrocardiogram recordings. Clin Auton Res 1997; 7: 127130.CrossRefGoogle ScholarPubMed
11.Khalil, M, Hessling, G, Bauch, M, Maier, C, Dickhaus, H, Ulmer, HE. Sympathovagal imbalance in pediatric patients with neurocardiogenic syncope during asymptomatic time periods. J Electrocardiol 2004; 37 Suppl: 166170.CrossRefGoogle ScholarPubMed
12.Márquez, MF, Urias, KI, Hermosillo, AG, et al. Familial vasovagal syncope. Europace 2005; 7: 472474.CrossRefGoogle ScholarPubMed
13.Cooper, CJ, Ridker, P, Shea, J, Creager, MA. Familial occurrence of neurocardiogenic syncope. N Engl J Med 1994; 331: 205.CrossRefGoogle ScholarPubMed
14.Lewis, SL, O’Toole, M. Familial occurrence of neurocardiogenic syncope. N Engl J Med 1994; 331: 1529.CrossRefGoogle ScholarPubMed
15.Kupper, NH, Willemsen, G, van den Berg, M, et al. Heritability of ambulatory heart rate variability. Circulation 2004; 110: 27922796.CrossRefGoogle ScholarPubMed
16.Singh, JP, Larson, MG, O’Donnell, CJ, Tsuji, H, Evans, JC, Levy, D. Heritability of heart rate variability: the Framingham Heart Study. Circulation 1999; 99: 22512254.CrossRefGoogle ScholarPubMed
17.Salim, MA, Ware, LE, Barnard, M, Alpert, BS, DiSessa, TG. Syncope recurrence in children: relation to tilt-test results. Pediatrics 1998; 102: 924926.CrossRefGoogle ScholarPubMed
18.Sheldon, R, Rose, S, Flanagan, P, Koshman, ML, Killam, S. Risk factors for syncope recurrence after a positive tilt-table test in patients with syncope. Circulation 1996; 93: 973981.CrossRefGoogle ScholarPubMed
19.Qingyou, Z, Junbao, D, Jianjun, C, Wanzhen, L. Association of clinical characteristics of unexplained syncope with the outcome of head-up tilt tests in children. Pediatr Cardiol 2004; 25: 360364.CrossRefGoogle ScholarPubMed
20.Furlan, R, Piazza, S, Dell’Orto, S, et al. Cardiac autonomic patterns preceding occasional vasovagal reactions in healthy humans. Circulation 1998; 98: 17561761.CrossRefGoogle ScholarPubMed
21.Grimm, W, Wirths, A, Hoffmann, J, Menz, V, Maisch, B. Heart rate variability during head-up tilt testing in patients with suspected neurally mediated syncope. Pacing Clin Electrophysiol 1998; 21: 24112415.CrossRefGoogle ScholarPubMed
22.Kouakam, C, Lacroix, D, Zghal, N, et al. Inadequate sympathovagal balance in response to orthostatism in patients with unexplained syncope and a positive head up tilt test. Heart 1999; 82: 312318.CrossRefGoogle Scholar
23.Suzuki, M, Hori, S, Nakamura, I, Nagata, S, Tomita, Y, Aikawa, N. Role of vagal control in vasovagal syncope. Pacing Clin Electrophysiol 2003; 26: 571578.CrossRefGoogle ScholarPubMed
24.Stewart, JM, Erb, M, Sorbera, C. Heart rate variability and the outcome of head-up tilt in syncopal children. Pediatr Res 1996; 40: 702709.CrossRefGoogle ScholarPubMed
25.Zygmunt, A, Stanczyk, J. Heart rate variability in children with neurocardiogenic syncope. Clin Auton Res 2004; 14: 99106.CrossRefGoogle ScholarPubMed