Heart Rate Variability

data type health indicator scans required facescan about hrv is simply a measure of the variation in time between each heartbeat this variation is controlled by a primitive part of the nervous system called the autonomic nervous system (ans) it works regardless of our desire and regulates, among other things, our heart rate, blood pressure, breathing, and digestion the ans is subdivided into two large components, the sympathetic and the parasympathetic nervous system, also known as the fight or flight mechanism and the relaxation response about the measurement standard deviation of nn intervals (sdnn) is a measure of heart rate variability (hrv) nn intervals refer to beat to beat intervals it is the time interval between each heartbeat sdnn is the standard deviation of the time intervals between each heartbeat, expressed in milliseconds (ms) category https //www wikiwand com/en/cardiovascular disease#citenotewho20112 category sdnn (ms) ◉ ◉ low 0 00 to < 10 80 ◉ ◉ low medium 10 80 to < 16 40 ◉ ◉ medium 16 40 to < 35 50 ◉ ◉ high 35 50 to < 51 50 ◉ ◉ very high 51 50 to < 80 00