A study investigated autonomic cardiac function in children and adolescents with long COVID. Fifty-six pediatric patients with long COVID (mean age 10.3 years) and 27 healthy controls (mean age 10.4 years) underwent 12-lead ECG, 24-hour Holter monitoring, and echocardiography. Heart rate variability (HRV) parameters, including time-domain and frequency-domain measures, were analyzed to assess autonomic function. Results showed significant differences in HRV parameters between the two groups, with long COVID patients exhibiting lower r-MSSD and higher VLF, LF, and HF values. No significant differences were found in echocardiographic parameters. The study suggests that children with long COVID have an imbalance in cardiac autonomic function, characterized by increased parasympathetic tone, similar to findings in adults. These findings indicate that autonomic dysfunction may play a role in long COVID symptoms, highlighting the need for further research to understand its clinical significance and develop therapeutic strategies. The study also notes limitations, including a small sample size and potential bias due to control group selection. Overall, the results suggest that autonomic dysfunction may be a key factor in long COVID, with implications for diagnosis and treatment in children.A study investigated autonomic cardiac function in children and adolescents with long COVID. Fifty-six pediatric patients with long COVID (mean age 10.3 years) and 27 healthy controls (mean age 10.4 years) underwent 12-lead ECG, 24-hour Holter monitoring, and echocardiography. Heart rate variability (HRV) parameters, including time-domain and frequency-domain measures, were analyzed to assess autonomic function. Results showed significant differences in HRV parameters between the two groups, with long COVID patients exhibiting lower r-MSSD and higher VLF, LF, and HF values. No significant differences were found in echocardiographic parameters. The study suggests that children with long COVID have an imbalance in cardiac autonomic function, characterized by increased parasympathetic tone, similar to findings in adults. These findings indicate that autonomic dysfunction may play a role in long COVID symptoms, highlighting the need for further research to understand its clinical significance and develop therapeutic strategies. The study also notes limitations, including a small sample size and potential bias due to control group selection. Overall, the results suggest that autonomic dysfunction may be a key factor in long COVID, with implications for diagnosis and treatment in children.