Reliability of measuring resting spontaneous cardiac baroreflex sensitivity using short sampling durations in healthy humans: Impact of central blood volume mobilization.

Our findings show that 1) reliability decreased progressively using the 3- and 1-min sampling durations; 2) the sitting position provides more reliable measures than all epoch durations measured in the supine position and; 3) the increases in the limits of agreement with shorter durations were attenuated by supine LBNP, suggesting that a cardiopulmonary baroreflex mechanism may play a role in the level of variability in resting cBRS.