Cardiac nodal and cardiac autonomic functions in children with vasovagal syncope
Cardiac nodal and cardiac autonomic functions in children with vasovagal syncope
Koca S, Paç FA, Ece I, Bağrul D, Çay S. Cardiac nodal and cardiac autonomic functions in children with vasovagal syncope. Turk J Pediatr 2016; 58: 498-502. In the present study, cardiac nodal (sinoatrial node and atrioventricular node) and cardiac autonomic functions have been investigated in children with vasovagal syncope (VVS). Thus, the effect of existing autonomic status on the characteristics of cardiac conduction system has been demonstrated in children with VVS. The study included 51 pediatric patients (the mean age was 14.01±2.79 years, range 7 to 18 years; 30 females), who were evaluated for syncope using ECG, Holter monitoring, and echocardiography, all of which showed normal findings. All patients underwent head-up tilt testing (HUTT), and the parameters of heart rate variability (HRV) (SDNN, SDANN, SDANNi, rMSSD, pNN50, HF, LF, VLF) were evaluated with the analysis of 24-hour Holter testing. Corrected sinus node recovery time (CNRT) and Wenckebach point (WP) were measured in all patients using transesophageal atrial stimulation. The patients were divided into groups according to HUTT results and evaluated accordingly. Cardiac nodal functions were normal in all patients. HRV parameters (HF, rMSSD, pNN50) indicating parasympathetic effect were higher in patients with positive HUTT results. CNRT did not differ significantly between patients with positive HUTT results and patients with negative HUTT results. However, WP was found to be higher in patients with positive HUTT results. The studies evaluating the parameters of HRV has demonstrated increased parasympathetic tonus in children with VVS. Impairment in cardiac nodal functions may not be expected in children with VVS. However, these patients may exhibit prolonged WP due to increased autonomic tonus in favor of parasympathetic activity.
___
- 1. Kapoor WN. Syncope. N Engl J Med 2000; 343:1856- 1862.
- 2. McHarg ML, Shinnar S, Rascoff H, Walsh CA. Syncope in childhood. Pediatr Cardiol, 1999; 18: 367-371.
- 3. Moya A, Sutton R, Ammirati F, et al. Guidelines for the diagnosis and management of syncope (version 2009). Eur Heart J 2009; 30: 2631-2671.
- 4. Alehan D, Ayabakan C, Ozer S. Heart rate variability and autonomic nervous system changes in children with vasovagal syncope. Pacing Clin Electrophysiol 2002; 25: 1331-1338.
- 5. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Circulation 1996; 93: 1043-1065.
- 6. 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): 166-170.
- 7. Shim SH, Park SY, Moon SN, et al. Baseline heart rate variability in children and adolescents with vasovagal syncope. Korean J Pediatr 2014; 57: 193-198.
- 8. Longin E, Reinhard J, von Buch C, Gerstner T, Lenz T, König S. Autonomic function in children and adolescents with neurocardiogenic syncope. Pediatr Cardiol 2008; 29: 763-770.
- 9. Sehra R, Hubbard JE, Straka SP, et al. Autonomic changes and heart rate variability in children with neurocardiac syncope. Pediatr Cardiol 1999; 20: 242- 247.
- 10. Stewart JM, Erb M, Sorbera C. Heart rate variability and the outcome of head-up tilt in syncopal children. Pediatr Res 1996; 40: 702-709.
- 11. Brembilla-Perrot B, Beurrier D, Houriez P, et al. Utility of transesophageal atrial pacing in the diagnostic evaluation of patients with unexplained syncope associated or not with palpitations. Int J Cardiol 2004; 96: 347-353.
- 12. Erdoğan I, Ozer S, Karagöz T, Sahin M, Celiker A. Clinical importance of transesophageal electrophysiologic study in the management of supraventricular tachycardia in children. Turk J Pediatr 2009; 51: 578-581.
- 13. Benson DW, Dunnigam A, Benditt DG, Pritzker ME, Thomson TR. Transesophageal study of in infant supraventricular tachycardia. Electrophysiologic characteristics. Am J Cardiol 1983; 52: 1002-1006.
- 14. Brembilla-Perrot B, Claudon O, Beurrier D, et al. Syncope in patients with normal ECG and without cardiac disease: value of ambulatory esophageal electrophysiology in determining etiology. Arch Mal Coeur Vaiss 2002; 95: 883-889.
- 15. Oddone D, Brignole M, Menozzi C, Gianfranchi L, Lolli G. Spontaneous occurrence of the induced cardioinhibitory vasovagal reflex. Pacing Clin Electrophysiol 1991; 14: 415-419.
- 16. Brignole M, Menozzi C, Bottoni N, et al. Mechanisms of syncope caused by transient bradycardia and the diagnostic value of electrophysiologic testing and cardiovascular reflexivity maneuvers. Am J Cardiol 1995; 76: 273-278.
- 17. Alboni P, Menozzi C, Brignole M, et al. Effects of permanent pacemaker and oral theophylline in sick sinus syndrome the THEOPACE study: A randomized controlled trial. Circulation 1997; 96: 260-266.