Multiscale time irreversibility to predict orthostatic intolerance in older people

2016 Computing in Cardiology Conference (CinC)

Cervigón³

2016

Self Cite

This study focuses on examining the hemodynamic profile in older people with symptoms of orthostatic intolerance (OI) undergoing an active stand and to investigate if their dynamic cardiovascular profile during six-minute walk distance would be different to those of controls. The database included a total of 65 participants, aged over 70 years of age (70.11±5.85), of whom 65% were females. The participants underwent a supine to stand orthostatic test with non-invasive beat to beat systolic (SBP) and diastolic blood pressure (DBP) and inter-beat interval (R-R) monitoring. Sample Entropy (SampEn) method was calculated at each phase. R-R SampEn values showed statistically significant differences during Phase 2 and Phase 4 between symptomatic and asymptomatic OI participants. This study empathizes the importance of entropy analysis to extract information of cardiovascular signals. SampEn based measures might provide useful indicators of pathological changes in cardiac activity and be suitable for the early detection of autonomic cardiovascular dysfunction.

Section: Resultssupporting

confidence: 92%

Section: Resultsmentioning

confidence: 80%

Sample Entropy Analysis of Hemodynamic Parameters in elderly with Orthostatic Intolerance Symptoms

Hortelano¹,

2016 Computing in Cardiology Conference (CinC)

Cervigón³

2016

Self Cite

“…In addition, a previous work highlights that response to mental stress shows a reduction in time asymmetry that reflects a shift in sympathovagal balance [ 35 ]. This result is consistent with a previous study that time irreversibility in hemodynamic parameters during the 6MWD that showed a similar trend during exercise stress [ 36 ].…”

Section: Discussionsupporting

confidence: 94%

Refined Multiscale Fuzzy Entropy to Analyse Post-Exercise Cardiovascular Response in Older Adults With Orthostatic Intolerance

Hortelano¹,

Castells

et al. 2018

Entropy

Self Cite

Orthostatic intolerance syndrome occurs when the autonomic nervous system is incapacitated and fails to respond to the demands associated with the upright position. Assessing this syndrome among the elderly population is important in order to prevent falls. However, this problem is still challenging. The goal of this work was to determine the relationship between orthostatic intolerance (OI) and the cardiovascular response to exercise from the analysis of heart rate and blood pressure. More specifically, the behavior of these cardiovascular variables was evaluated in terms of refined composite multiscale fuzzy entropy (RCMFE), measured at different scales. The dataset was composed by 65 older subjects, 44.6% (n = 29) were OI symptomatic and 55.4% (n = 36) were not. Insignificant differences were found in age and gender between symptomatic and asymptomatic OI participants. When heart rate was evaluated, higher differences between groups were observed during the recovery period immediately after exercise. With respect to the blood pressure and other hemodynamic parameters, most significant results were obtained in the post-exercise stage. In any case, the symptomatic OI group exhibited higher irregularity in the measured parameters, as higher RCMFE levels in all time scales were obtained. This information could be very helpful for a better understanding of cardiovascular instability, as well as to recognize risk factors for falls and impairment of functional status.

“…Moreover, these results were complemented by the drop in the baroreflex gain during postural syncope [12][13][14][15]. Attention should also be drawn to results shown by others studies, where symptomatic OI patients illustrated a decrease in the time irreversibility indexes during active and passive stages [4]. Moreover, the directionality index from SBP to R-R illustrated SBP as a driver in the preferred direction of flow information.…”

Section: Resultsmentioning

confidence: 61%

“…The transition from the supine to the upright position requires a reorganization of the mechanisms of cardiovascular control that may lead to neurally mediated syncope [1]. Other studies have already shown interesting results on changes in the irregularity and irreversibility of systolic blood pressure (SBP) and heart rate (HR) in patients with OI, showing different entropy measures and time irreversibility indices as efficient markers to detect changes in heart rate variability, elicited by orthostatic in older people [2][3][4]. The magnitude of HR changes in relations to blood pressure (BP) changes traditionally considered to be mediated by the simulation of baroreceptors is expressed as baroreflex sensitivity (BRS).…”

Section: Introductionmentioning

confidence: 99%

Casual Interactions between Blood Pressure and Cardiac Inter:beat Intervals in Older People with Orthostatic Intolerance

Hortelano

2016 Computing in Cardiology Conference (CinC)

Cervigón

2016

Self Cite

The aim of our study was to analysed the proportion of both casual direction between inter-beat interval (R-R) and non-invasive beat to beat blood pressure (BP) during six minutes walking distance test between symptomatic and asymptomatic participants of orthostatic intolerance (OI). We analysed 65 older subjects, of whom 42 were women. The participants underwent a supine to stand orthostatic test with non-invasive beat-to-beat systolic blood pressure and diastolic blood pressure and R-R monitoring. Transfer Entropy (TE) method was applied to identify relationship between hemodynamical variables. The directionality index quantifies the preferred direction of information flow from difference between both directional couplings. Results show a higher symmetric bidirectional couplings in asymptomatic OI group. These results show that systolic blood pressure affects heart rate; nevertheless directional coupling between these cardiovascular signals is altered depending on changes in autonomic control introduced by the orthostatic test.