@article{article_1626897, title={Evaluation of Heart Rate Variability in Children Presenting with Syncope}, journal={Acta Medica Nicomedia}, volume={8}, pages={217–228}, year={2025}, DOI={10.53446/actamednicomedia.1626897}, author={Yukcu, Bekir and Diler Durgut, Betül and Tekin, Emine and Yavuzyilmaz, Fidel Ceren}, keywords={heart rate variability, vasovagal syncope, pediatrics, 24-hour Holter monitoring, autonomic dysfunction}, abstract={Objective: This study evaluated the diagnostic value of heart rate variability (HRV) parameters obtained from 24-hour Holter monitoring in pediatric patients with vasovagal syncope (VVS) and compared them to a control group. The study also analyzed time-domain and frequency-domain HRV parameters to explore the autonomic mechanisms underlying VVS and the diagnostic potential of HRV. Methods: This retrospective study was conducted at *** Women’s and Children’s Health Training and Research Hospital. Forty-one children with VVS and 36 healthy controls undergoing 24-hour Holter monitoring for ventricular extrasystoles were included. Comprehensive cardiac, neurological, and demographic evaluations were performed for all participants. HRV parameters were analyzed from 24-hour Holter recordings, and group comparisons were performed using the Mann–Whitney U test. Spearman correlation and Receiver Operating Characteristic analyses were also conducted. Results: Time-domain HRV parameters were significantly lower in the syncope group compared to those in the control group (p < 0.05). No significant differences were observed in frequency-domain parameters. The standard deviation of normal-to-normal RR intervals (SDNN) demonstrated the highest diagnostic accuracy, with a cut-off value of <163 ms (Area Under the Curve: 0.753, sensitivity: 72.2%, specificity: 75.6%). Conclusion: HRV parameters obtained from 24-hour Holter monitoring provide valuable insights into autonomic dysfunction in pediatric VVS. SDNN emerged as a strong diagnostic marker in this regard. Further studies with larger, more homogeneous populations are needed to establish normative HRV values and refine diagnostic criteria in pediatric populations.}, number={2}, publisher={Kocaeli University}