HRV Metrics: PNN50
PNN50 is the proportion of NN50 divided by the total number of NN (R-R) intervals. NN50 is the number of times successive heartbeat intervals exceed 50ms. PNN50 is closely correlated with Parasympathetic Nervous System activity, though many researchers prefer RMSSD - as do we!
For healthy individuals ages 25-74 years, the range is -3% to 43%. You can find your specific healthy range in the Population Comparison feature of the app!