Heart rate variability and heart rate turbulence in patients with vasovagal syncope

Aim    The autonomic nervous system plays an important role in the pathogenesis of vasovagal syncope, but studies on the effect of basal autonomic tone have found confusing results. The aim of this study was to investigate the effect of basal autonomic functions, as assessed by heart rate variability (HRV) and heart rate turbulence (HRT), in patients with vasovagal syncope.
Material and methods    Patients who underwent head-up tilt test (HUTT) due to unexplained syncope and who had a 24 hr Holter ECG recording in the same period were retrospectively analyzed. Patients with diabetes, a history of myocardial infarction, heart failure, orthostatic hypotension, atrial fibrillation, or use of vasoactive drugs, such as beta blockers, were excluded from the study. 161 patients who met these criteria were included in the study. Time domain HRV parameters from Holter ECG recordings and HRT parameters from patients with sufficient number of ventricular premature contractions were measured.
Results    The age of the patients varied from 16 to 75 yrs (mean: 44.8±18.5 yrs). HUTT results of 60 (37.2 %) patients were evaluated as positive. There were no significant differences in the basal demographic, clinical, or laboratory findings of the tilt-positive and tilt-negative patient groups. Likewise, there were no significant differences between the time domain HRV parameters and HRT parameters of both groups.
Conclusion    HRV and HRT parameters reflecting basal autonomic function were not different between HUTT positive and HUTT negative patient groups. These findings suggest that basal autonomic functions have no effect on vasovagal syncope pathogenesis.

1. Brignole M, Moya A, de Lange FJ, Deharo J-C, Elliott PM, Fanciulli A et al. 2018 ESC Guidelines for the diagnosis and management of syncope. European Heart Journal. 2018;39(21):1883–948. DOI: 10.1093/eurheartj/ehy037

2. Benditt DG, Ferguson DW, Grubb BP, Kapoor WN, Kugler J, Lerman BB et al. Tilt table testing for assessing syncope. Journal of the American College of Cardiology. 1996;28(1):263–75. DOI: 10.1016/0735-1097(96)00236-7

3. Iwase S, Nishimura N, Mano T. Role of sympathetic nerve activity in the process of fainting. Frontiers in Physiology. 2014;5:343. DOI: 10.3389/fphys.2014.00343

4. Vallejo M, Hermosillo AG, Infante O, Cárdenas M, Lerma C. Cardiac Autonomic Response to Active Standing in Adults With Vasovagal Syncope. Journal of Clinical Neurophysiology. 2015;32(5):434–9. DOI: 10.1097/WNP.0000000000000204

5. Bauer A, Malik M, Schmidt G, Barthel P, Bonnemeier H, Cygankiewicz I et al. Heart Rate Turbulence: Standards of Measurement, Physiological Interpretation, and Clinical Use. Journal of the American College of Cardiology. 2008;52(17):1353–65. DOI: 10.1016/j.jacc.2008.07.041

6. Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. European Heart Journal. 1996;17(3):354–81. PMID: 8737210

7. Kochiadakis GE, Orfanakis A, Chryssostomakis SI, Manios EG, Kounali DK, Vardas PE. Autonomic Nervous System Activity During Tilt Testing in Syncopal Patients, Estimated by Power Spectral Analysis of Heart Rate Variability. Pacing and Clinical Electrophysiology. 1997;20(5):1332–41. DOI: 10.1111/j.1540-8159.1997.tb06788.x

8. Zygmunt A, Stanczyk J. Heart rate variability in children with neurocardiogenic syncope. Clinical Autonomic Research. 2004;14(2):99–106. DOI: 10.1007/s10286-004-0168-0

9. Arslan, Uġur, Ozdemir M, Turkoglu, Sedat, Yazici, Güliz Erdem, Cengel A. Heart rate variability in neurally mediated reflex syncope. Acta Cardiologica. 2006;61(6):599–602. DOI: 10.2143/AC.61.6.2017957

10. The Consensus Committee of the American Autonomic Society and the American Academy of Neurology. Consensus statement on the definition of orthostatic hypotension, pure autonomic failure, and multiple system atrophy. Neurology. 1996;46(5):1470. DOI: 10.1212/WNL.46.5.1470

11. Brignole M, Moya A, de Lange FJ, Deharo J-C, Elliott PM, Fanciulli A et al. Practical Instructions for the 2018 ESC Guidelines for the diagnosis and management of syncope. European Heart Journal. 2018;39(21):e43–80. DOI: 10.1093/eurheartj/ehy071

12. Brignole M. New classification of haemodynamics of vasovagal syncope: beyond the VASIS classification. Analysis of the pre-syncopal phase of the tilt test without and with nitroglycerin challenge. Europace. 2000;2(1):66–76. DOI: 10.1053/eupc.1999.0064

13. Barthel P, Schneider R, Bauer A, Ulm K, Schmitt C, Schömig A et al. Risk Stratification After Acute Myocardial Infarction by Heart Rate Turbulence. Circulation. 2003;108(10):1221–6. DOI: 10.1161/01.CIR.0000088783.34082.89

14. Iacoviello M, Guida P, Forleo C, Sorrentino S, D’Alonzo L, Favale S. Impaired arterial baroreflex function before nitrate-induced vasovagal syncope during head-up tilt test. Europace. 2008;10(10):1170–5. DOI: 10.1093/europace/eun217

15. Klemenc M, Štrumbelj E. Predicting the outcome of head-up tilt test using heart rate variability and baroreflex sensitivity parameters in patients with vasovagal syncope. Clinical Autonomic Research. 2015;25(6):391–8. DOI: 10.1007/s10286-015-0318-6

16. Shim SH, Park S-Y, Moon SN, Oh JH, Lee JY, Kim HH et al. Baseline heart rate variability in children and adolescents with vasovagal syncope. Korean Journal of Pediatrics. 2014;57(4):193–8. DOI: 10.3345/kjp.2014.57.4.193

17. Lazzeri C, Villa G, Barletta G, Franchi F. 24-Hour Heart Rate Variability in Patients with Vasovagal Syncope. Pacing and Clinical Electrophysiology. 2000;23(4):463–8. DOI: 10.1111/j.1540-8159.2000. tb00828.x

18. Kochiadakis G, Marketou M, Koukouraki S, Parthenakis F, Chlouverakis G, Karkavitsas N et al. Cardiac autonomic disturbances in patients with vasovagal syndrome: comparison between iodine-123-metaiodobenzylguanidine myocardial scintigraphy and heart rate variability. Europace. 2012;14(9):1352–8. DOI: 10.1093/europace/eus063

19. Balcıoğlu AS, Muderrisoglu H. Diabetes and cardiac autonomic neuropathy: Clinical manifestations, cardiovascular consequences, diagnosis and treatment. World Journal of Diabetes. 2015;6(1):80–91. DOI: 10.4239/wjd.v6.i1.80

20. Barsukov A.V., Chepcheruk O.G., Glukhovskoi D.V., Yakovlev V.V., Gordienko A.V. Features of changes in volume-impedance hemodynamic indicators during the tilt test in young males with a history of vasovagal syncopes. Kardiologiia. 2019;59(11):31–8.DOI: 10.18087/cardio.2019.11.n527

21. Watso JC, Farquhar WB. Hydration Status and Cardiovascular Function. Nutrients. 2019;11(8):1866. DOI: 10.3390/nu11081866

22. Fitzpatrick AP, Banner N, Cheng A, Yacoub M, Sutton R. Vasovagal reactions may occur after orthotopic heart transplantation. Journal of the American College of Cardiology. 1993;21(5):1132–7. DOI: 10.1016/0735-1097(93)90235-S

23. Saadjian AY, Gerolami V, Giorgi R, Mercier L, Berge-Lefranc J-L, Paganelli F et al. Head-up tilt induced syncope and adenosine A2A receptor gene polymorphism. European Heart Journal. 2009;30(12):1510–5. DOI: 10.1093/eurheartj/ehp126

24. Brignole M, Iori M, Solari D, Bottoni N, Rivasi G, Ungar A et al. Efficacy of theophylline in patients with syncope without prodromes with normal heart and normal ECG. International Journal of Cardiology. 2019;289:70–3. DOI: 10.1016/j.ijcard.2019.03.043

25. Brignole M, Groppelli A, Brambilla R, Caldara GL, Torresani E, Parati G et al. Plasma adenosine and neurally mediated syncope: ready for clinical use. EP Europace. 2020;22(6):847–53. DOI: 10.1093/europace/euaa070