Dear Editor,

The article by Davanço et al., entitled “Post-COVID-19 Syndrome and Autonomic Repercussions on Cardiovascular Variables” (ABC Heart Fail Cardiomyop. 2023; 3(3): e20230056), makes an important contribution to understanding the autonomic repercussions of COVID-19 on cardiovascular modulation. This study stands out for addressing an emerging and highly relevant clinical topic by investigating heart rate variability (HRV) parameters in patients with post-COVID-19 syndrome, using robust temporal and spectral domain measures. The methodological rigor, adherence to STROBE guidelines, and adequate characterization of the comparison groups are noteworthy, lending solidity to the conclusions presented.

The correlation between increased parasympathetic indices (RMSSD, HF) and reduced global variability parameters suggests a complex autonomic adaptation, possibly mediated by persistent inflammatory mechanisms— a hypothesis of great pathophysiological value.

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