Phase-Rectified Signal Averaging (PRSA): DC and AC

Computes the deceleration capacity (DC) and acceleration capacity (AC) of the RR series by phase-rectified signal averaging (Bauer et al. 2006). Anchors are points where the RR level increases (DC) or decreases (AC); segments centered on the anchors are averaged into a PRSA curve, and the capacity is a Haar-wavelet coefficient of that curve at scale s.

Usage

ecgPRSA(rr, T = 1L, s = 2L, L = 15L)

Arguments

rr: RR intervals (ms): a numeric vector or a data.frame with an rr_ms column.
T: Averaging window (beats) for anchor selection (default 1: an anchor is a single beat larger/smaller than the previous).
s: Wavelet scale for the DC/AC coefficient (default 2).
L: Half-length of the averaged PRSA segments (default 15; must be \(\ge s\)).

Value

A list with dc (deceleration capacity, ms; positive with dominant decelerations), ac (acceleration capacity, ms; negative), the PRSA curves prsa_dc/prsa_ac, the anchor counts n_dc/n_ac, and the parameters T, s, L.

References

Bauer, A. et al. (2006). Deceleration capacity of heart rate as a predictor of mortality after myocardial infarction: cohort study. Lancet, 367(9523), 1674-1681.

Examples

set.seed(1)
rr <- 800 + cumsum(rnorm(600, sd = 3))       # RR random walk
prsa <- ecgPRSA(rr)
c(DC = prsa$dc, AC = prsa$ac)
#>        DC        AC 
#>  1.245939 -1.062157