Heart rate adjusted heart rate variability reliable predictor of risk of sudden cardiac death

While the exponential power coefficients varied widely between groups, the majority of HRV measures exponentially degraded as HR increased. 

With a median AUC of 0.72[0.11], the HRVI measures distinguishing between patients at low, medium, and high risk. 

This was a significant improvement over the standard long-term and short-term HRV without correction. 

Compared to conventional short-term HRV measurements, the average CV of the HRVI metrics was also much lower (0.09 0.02 vs. 0.24 0.13, p 0.01).

In conclusion, similar exponential decay relationships between HRV measures and HR were seen in HCM patients with medium risk of SCD, although at different rates when compared to low risk healthy controls and high risk SCD patients. When assessed using the customized HR-based HRV adjustment approach, HCM patients had autonomic nervous dysfunction, which was manifested as reduced vagal activity and poor sympatho-vagal balance. The HRV measures with HR adjustment offer dependable and effective risk classification of SCD.

Reference: 

Yan, S.-P., Song, X., Wei, L., Gong, Y.-S., Hu, H.-Y., & Li, Y.-Q. (2023). Performance of heart rate adjusted heart rate variability for risk stratification of sudden cardiac death. In BMC Cardiovascular Disorders (Vol. 23, Issue 1). Springer Science and Business Media LLC. https://doi.org/10.1186/s12872-023-03184-0