Heart-Rate Asymmetry (Poincare Plot Asymmetry) Descriptors

Computes heart-rate asymmetry (HRA) descriptors from RR interval data. The Poincare plot is asymmetric about the line of identity because heart-rate decelerations (prolongations of RR, points above the line, \(RR_{n+1} > RR_n\)) and accelerations (shortenings, points below the line) contribute unequally to variability – a signature of vagal activity and of the temporal irreversibility of heart-rate dynamics. Decelerations typically dominate short-term variability while accelerations dominate long-term variability (Piskorski & Guzik, 2011).

Usage

ecgHRVasymmetry(rr)

Arguments

rr

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

Value

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

channel

Channel identifier.

gi

Guzik's Index (\ points from the line of identity divided by that of all points.

si

Slope Index (\ points divided by that of all points.

ai

Area Index (\ points divided by that of all points.

pi

Porta's Index (\ the number of points off the line of identity.

c1d, c1a

Contributions of decelerations / accelerations to short-term HRV (c1d + c1a = 1).

sd1d, sd1a

Short-term variance components of decelerations / accelerations (ms).

c2d, c2a

Contributions of decelerations / accelerations to long-term HRV (c2d + c2a = 1).

sd2d, sd2a

Long-term variance components (ms).

cd, ca

Total contributions of decelerations / accelerations to HRV.

sdnnd, sdnna

Total variance components (ms).

A value indicating asymmetry is c1d > c1a (decelerations dominate short-term variability). Columns are NA for channels with fewer than three RR intervals.

References

Guzik, P., et al. (2006). "Heart rate asymmetry by Poincare plots of RR intervals." Biomedizinische Technik, 51(4), 272–275.

Piskorski, J., & Guzik, P. (2011). "Asymmetric properties of long-term and total heart rate variability." Medical & Biological Engineering & Computing, 49(11), 1289–1297. doi:10.1007/s11517-011-0834-z

Porta, A., et al. (2008). "Temporal asymmetries of short-term heart period variability are linked to autonomic regulation." American Journal of Physiology, 295(2), R550–R557.

See also

ecgHRVpoincare for the symmetric Poincare descriptors (SD1/SD2), ecgDFA for detrended fluctuation 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)
ecgHRVasymmetry(rr)
#>   channel       gi       si       ai       pi       c1d       c1a    sd1d
#> 1       1 49.90861 49.90732 49.91001 50.50167 0.5215768 0.4784232 12.3178
#>       sd1a       c2d       c2a     sd2d     sd2a        cd        ca    sdnnd
#> 1 11.79723 0.4836271 0.5163729 22.78211 23.54076 0.4917202 0.5082798 18.31329
#>     sdnna
#> 1 18.6191