Heart Rate Variability, Average Standard Deviation NN Interval Measurement

**Semantic type:** Diagnostic Procedure

**Definition:** A measurement of the fluctuation in the time intervals between adjacent heartbeats, based on the average standard deviation of the means of consecutive 5 minute NN intervals over a period of time.

**Synonyms:** - HRVSDANN - Heart Rate Variability, Average Standard Deviation NN Interval - Heart Rate Variability, SDANN - Heart Rate Variability, SDANN