Assessment of latency in baroreflex control of heart rate during spontaneous behavior

This study proposes a new simplified approach for estimating the latency in the baroreflex control of heart rate by the analysis of systolic blood pressure (SBP) and RR interval (RRI) spontaneous variability. Application of this technique on SBP and RRI 24-h recordings, allowed us to identify a large fluctuation of the baroreflex latency over time with a circadian pattern characterised by a reduction of the latency at night. Since our approach provides a quantification of the latency in terms of heart beats, there was the possibility that the results would be influenced by the RRI. The observed absence of any significant correlation between latency and RRI excluded this adverse possibility. These results encourage the use of the proposed procedure for obtaining a simple and noninvasive measure of the baroreflex latency in daily life condition.