Dynamical interaction between heart rate and blood pressure of end-stage renal disease patients evaluated by cross recurrence plot diagonal analysis

Abstract

The assessment of spontaneous variability of blood pressure and heart rate is based on specific physiological hypotheses about dynamic features, for example, the baroreflex modulation of heart rate over time in daily life. Usually, arterial baroreflex control of heart rate is explored without delays between blood pressure and heart rate data points, within a narrow range of values, excluding the analysis of saturation regions or low-threshold changes. In this work, we examine the dynamic interactions between systolic blood pressure (SBP) and interbeat interval (IBI), in 15-min length time series and for the first time using the analysis of diagonals derived from a cross-recurrence plots in healthy persons and end-stage renal disease (ESRD) patients. We found that ESRD patients have stronger intermittent dynamical interactions between IBI and SBP, but they lose most of the dynamical interactions. Although healthy subjects exhibit a continuously changing order of precedence between IBI and SBP at different lags, ESRD patients preserve this changing order of precedence only for lags >0 beats. NEW & NOTEWORTHY This study is the first to compare the time-variant pattern of systolic blood pressure (SBP) and interbeat interval (IBI) coupling between ESRD patients and healthy volunteers through the analysis of diagonal in cross-recurrence plots, and in the face of an orthostatic challenge. Our results demonstrated alternant interactions on the order of precedence (IBI → SBP or SBP→ IBI) at different time delays. This pattern is different in resting position and during active standing for the two groups studied, and interestingly, some association patterns are lost in ESRD patients. These patterns of alternant interactions on the order of precedence could be related to autonomic neural activities and cardiovascular synchronization at different scales both in time and space. This could reflect physiological adaptive flexibility of cardiovascular regulation. Losing some association patterns in ESRD may be the result of chronic adjustments of many physiological mechanisms (including chronic sympathetic hyperactivity), which could increase cardiovascular vulnerability to hemodynamic challenges.

Association between Mean Heart Rate and Recurrence Quantification Analysis of Heart Rate Variability in End-Stage Renal Disease

“…Some regulatory systems can become modified, or a particularly compensatory output can be lost, so when we study the dynamical behavior of the system under different stimuli, we need sensitive tools to disclose these regulatory changes and distinguish the physiological adaptability from drifting homeostatic modifications. The recurrence dynamical response of HRV (evaluated through the representation of all state variables in the phase space and the quantitative analysis of its recurrence plot) offers the possibility of inferring the acute and chronic plasticity of the cardiovascular system both in healthy subjects [ 8 , 41 ] and ESRD patients [ 9 , 10 , 11 ]. The physiological stress during active standing in healthy subjects increases determinism and entropy, reflecting an intensification of the interactions (or dependency) between the dynamic states.…”

“…Simultaneously, the RQA indices based on vertical lines show that the orthostatic stress bounds the dynamic behavior of the system within fewer phase space regions [ 9 ]. The effect of ESRD upon the cardiovascular dynamics seems to be in the same direction, acting as a stressor of the system that limits the number of phase space regions visited by the system (i.e., vertical-based indices are larger compared to those of healthy subjects even at rest in the supine position) and increasing the time required to revisit a state [ 9 , 10 , 11 ]. Given that after hemodialysis, the RQA indices show changes in the same direction of the response to active standing observed in healthy subjects, we argue that the RQA indices of ESRD patients evidence a preserved ability to adjust their cardiovascular dynamics when facing a hemodynamic challenge.…”

“…In that work, all the assessed RQA indices (except for the longest diagonal line) behaved similarly for different recurrence rates, increasing significantly and consistently in both positions (supine and active standing) if the recurrence rate is increased. These indices are sensitive to recurrence rates in the range of 1−20% [ 8 ], and we used a fixed recurrence rate < 7% to construct the recurrence plots [ 9 , 11 ].…”

“…The entire set of adjustments needs well-integrated variables, different regulatory levels, and timing actions that despite appearing redundant can be absent or become modified when comparing the dynamical behavior of the system under different stimuli [ 6 , 7 ]. The dynamical response shown by heart rate variability (HRV) offers the possibility of inferring the acute and chronic adaptability of the cardiovascular system both in healthy subjects [ 8 ] and ESRD patients [ 4 , 9 , 10 , 11 ].…”

“…Although such correlation is lost in ESRD patients before hemodialysis, it is recovered after hemodialysis and so considered as an indicator of cardiovascular adaptability [ 24 , 26 ] as well as a potential marker to differentiate between adaptive changes to achieve a precise demand response and long-term adjustments for facing pathophysiological alterations that, in other physiological contexts, could be deleterious. During an orthostatic challenge, the change from a supine to standing up position modifies some RQA indices [ 11 ]. Nonetheless, the influence of the mean heart rate on the RQA indices still has not been explored.…”