What is ln(RMSSD) proxy score?
The natural logarithm of RMSSD is a derived HRV metric that normalizes the skewed distribution of raw RMSSD values. It provides a more statistically linear scale for comparing HRV across populations and monitoring physiological trends over time.
What is SDNN?
SDNN (standard deviation of all normal-to-normal RR intervals) is a comprehensive HRV metric capturing overall autonomic variability over a recording period. It is used in clinical cardiology and long-term stress and health assessments.