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About the New Software

HRV SDNN Parameters

The newly upgraded Heart Quest (HQ) Heart Rate Variability software has many new features! The HQ now has the ability to determine HRV SDNN Parameters.  It also incorporates the fundamentals of traditional Chinese medicine:  Meridians and the Five Elements.


What is the SDNN?

There are many methods of analyzing Heart Rate Variability.  The most common index of overall of Heart Rate Variability is called the SDNN.  SDNN stands for the Standard Deviation of NN intervals (beat-to-beat intervals).   SDNN is the standard deviation of normal to normal heartbeats.  It is highly correlated and considered to provide good estimates of Autonomic Nervous System (ANS) activity.  It reflects our ability to respond quickly, dynamically and effectively to a crisis.  The higher the number, the better.


SDNN Range

Very Poor      -           Less than 30

Poor              -           30 to 50

Moderate      -           51-100

Optimal          -          More than 100

(Note:  Normal Range is 55-65)

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