Skip to main content

Table 3 HRV parameters

From: The acute effects of aerobic exercise on sleep in patients with depression: study protocol for a randomized controlled trial

Method

Measure of variability

Calculation of variable

Physiological mechanism

Time-domain methods

Statistical

RMSSD

Root mean square of successive differences of NN intervals

Short-term components of HRV, vagal modulation

SDNN

Standard deviation of the of all NN intervals

Overall HRV, cyclic components responsible for HRV

SDANN

Standard deviation of the averages of NN intervals in all 5-min segments of the entire recording (only for nocturnal HRV)

Long-term components of HRV

Frequency domain methods

Lomb-Scargle Periodogram

and

Fast Fourier transformation

TP

Total power: power density spectrum in the frequency range of 0.00001 to 0.4 Hz [ms2]

Overall HRV

LF

Low-frequency power: power density spectrum in the frequency range of 0.04 to 0.15 Hz [ms2]

Sympathetic and vagal activity, baroreflex activity (vasomotor tone)

HF

High-frequency power: power density spectrum in the frequency range of 0.15 to 0.40 Hz [ms2]

Vagal modulation

LF/HF

Ratio LF [ms2]/HF [ms2]

Sympathetic and vagal modulation

  1. Calculations are based on [135, 142]. Descriptions of physiological mechanisms are based on [142, 143]