Fractal correlation property of heart rate variability in response to the postural change maneuver in healthy women

Abstract

BackgroundWe evaluated the effects of the PCM on the fractal analysis of the HRV in healthy womenMethodWe evaluated healthy women between 18 and 30 years old. HRV was analyzed in the time (SDNN, RMSSD, NN50 and pNN50) and frequency (LF, HF and LF/HF ratio) domains as well as short and long-term fractal exponents (alpha-1 and alpha-2) of the detrended fluctuation analysis (DFA). HRV was recorded at rest for ten minutes at seated rest and then the women quickly stood up from a seated position in up to three seconds and remained standing for 15 minutes. HRV was recorded at the following time: rest, 0–5 min, 5–10 min and 10–15 min during standing.ResultsWe observed decrease (p < 0.05) in the time-domain indices of HRV between seated and 10–15 minutes after the volunteer stood up. The LF (ms2) and HF (ms2) indices were also reduced (p < 0.05) at 10–15 minutes after the volunteer stood up compared to seated while the LF (nu) was increased at 5–10 min and 10–15 min (p < 0.05). The short-term alpha-1 exponent was increased (p < 0.05) at all moments investigated compared to seated. Increase in the properties of short-term fractal correlations of heart rate dynamics accompanied by a decrease in the parasympathetic modulation and global HRV was observed in response to the postural change maneuver.ConclusionWe suggest that fractal analysis of HRV is more sensitive than frequency and time-domain analysis of HRV during the postural change maneuver.

Multifractal‐Multiscale Analysis of Cardiovascular Signals: A DFA‐Based Characterization of Blood Pressure and Heart‐Rate Complexity by Gender

“…We showed that ( , ) of IBI decreases with in healthy individuals sitting at rest, from values typical for fractional Brownian motions to values typical for fractional Gaussian noises. A similar behavior has been previously observed in other studies that applied DFA with traditional monofractal approaches (i.e., with = 2 only) to analyze the heart-rate variability in sitting volunteers at rest [16,28]. A possible explanation for this trend has been already proposed, based on the hypothesis that the heart-rate dynamics depend on the superposition of two fractal processes simultaneously modulating the heart rate [7,29].…”

A blunted sympathetic and accentuated parasympathetic response to postural change in subjects with depressive disorders

“…The subject remained seated at rest with spontaneous breathing. After 10 min the volunteers quickly stood up from a seated position in up to three seconds according to verbal command and remained standing for 10 min (de Souza et al, 2014). Heart rate variability (HRV) was analyzed at two moments: 10 min seated rest with spontaneous breathing, and 10 min at standing position.…”

“…Normal HRV activity in response to postural change reflects a shift from parasympathetic predominance at rest to sympathetic control while standing (de Souza et al, 2014). Some studies have reported an attenuated or absent HRV response to postural change in subjects with chronic diseases such as hypertension and diabetes , suggesting that autonomic impairment and early sympathetic dysfunction may be present in such individuals.…”

Nonlinear Analysis of Heart Rate Variability: A Comprehensive Review

“…Souza et al [8] (2014) evaluated healthy women aged 18-30 years studying the behavior of HRV in response to the postural change maneuver, using linear and nonlinear variables. They observed that the short-term alpha-1 exponent was significantly increased at all moments investigated compared to seat.…”