HRV Time-Domain Metrics

Compute standard heart rate variability (HRV) time-domain metrics from RR interval data. Calculates SDNN, RMSSD, pNN50, mean RR interval, and mean heart rate for each channel.

Usage

ecgHRVtime(rr, rhythm_check = TRUE)

Arguments

rr

A data.frame with columns channel, rr_ms, and time_sec, as returned by ecgRRintervals.

rhythm_check

Logical; if TRUE (default), gate the result on ecgDetectAF: metrics for channels classified as AF or frequent ectopy are set to NA and rhythm/hrv_valid columns are appended (HRV is undefined in atrial fibrillation).

Value

A data.frame with one row per channel and the following columns:

channel

Integer channel index.

mean_rr

Mean RR interval in milliseconds.

sdnn

Standard deviation of all RR intervals (ms), reflecting overall HRV.

rmssd

Root mean square of successive RR interval differences (ms), reflecting short-term vagal modulation.

pnn50

Percentage of successive RR intervals differing by more than 50 ms.

mean_hr

Mean heart rate in beats per minute (60000 / mean_rr).

References

Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology (1996). "Heart rate variability: Standards of measurement, physiological interpretation and clinical use." Circulation, 93(5), 1043–1065.

See also

ecgRRintervals for computing RR intervals, ecgHRVfreq for frequency-domain HRV analysis, ecgHRVnonlinear for nonlinear HRV metrics, ecgQualityCheck for ectopic beat detection before analysis.

Examples

set.seed(1)
n <- 300
time_sec <- cumsum(rep(0.85, n))
rr_ms <- 850 + 30 * sin(2 * pi * 0.1 * time_sec) + rnorm(n, sd = 15)
rr <- data.frame(channel = 1L, rr_ms = rr_ms, time_sec = time_sec)
ecgHRVtime(rr)
#>   channel  mean_rr     sdnn    rmssd   pnn50  mean_hr rhythm hrv_valid
#> 1       1 850.8693 26.07409 24.08028 3.67893 70.51612  sinus      TRUE