Characteristic of Mayer Waves in Electrophysiological, Hemodynamic and Vascular Signals

2020 ◽  
Vol 30 (03) ◽  
pp. 2050003 ◽  
Author(s):  
K. J. Blinowska ◽  
P. Lachert ◽  
J. Zygierewicz ◽  
D. Janusek ◽  
P. Sawosz ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Matching Pursuit ◽  
Blood Oxygenation ◽  
Common Mechanism ◽  
Mayer Waves ◽  
Time Frequency ◽  
Cerebral Blood Oxygenation ◽  
Central Pacemaker

We evaluated the properties of oscillations in the Mayer waves (MW) frequency range ([Formula: see text][Formula: see text]Hz) detected in blood pressure, heart rate variability, cerebral blood oxygenation changes and evolution of electroencephalographic (EEG) rhythms to elucidate the mechanisms of MW generation. We examined the persistence of MW in different signals and stability of their oscillations on the level of individual MW waveforms, which was achieved by applying matching pursuit (MP). MP yields adaptive time-frequency approximation of signal’s structures in terms of frequency, amplitude, time occurrence, and time-span. The number of waveforms contributing to 95% of the energy of the signals was vastly different for the time series, but the average number of waveforms conforming to the MW criteria was almost the same ([Formula: see text] per 120[Formula: see text]s epoch). In all the investigated signals, MW had the same distributions of frequency and the number of cycles. We show that the MW energy ratios in different signals varied strongly, [Formula: see text]. The highest percentage of MW energy was observed in blood pressure signals, heart rate variability, and reduced hemoglobin, in contrast to brain signals and oxygenated hemoglobin. The percentage of MW energy was related to the strength of causal influence exerted by them on the other signals. Our results indicate existence of a common mechanism of MW generation and support the hypothesis of MW generation in the baroreflex loop; however, they do not exclude the action of a central pacemaker.

scholarly journals CORRECTION OF RESISTANT ARTERIAL HYPERTENSION IN PATIENTS WITH CHRONICKIDNEYDISEASE STAGE I–III

2014 ◽  
pp. 3-8
Author(s):  
O. M. Loboda
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Resistant Hypertension ◽  
Goal Blood Pressure ◽  
Antihypertensive Medications ◽  
Time Frequency ◽  
Before And After ◽  
Achieve Goal Blood Pressure ◽  
Resistant Arterial Hypertension

Aim. The aim was to investigate the use of the I1–imidazoline receptor agonist moxonidine as an ‘add–on’ agent and determine its effect on heart rate variability in patients with CKD st. I–III and resistant hypertension. Methods. We investigated the safety and efficacy of moxonidine (200–600 mg) in a group of 35patients with CKD st. I–III whose had prior treatment with three or more antihypertensive medications, although without adequate control [systolic blood pressure (SBP) 145–165 mm Hg and/or diastolic BP (DBP) 95–100 mm Hg]. BP was measured according to internationally accepted guidelines before and after 3 month of treatment with moxonidine used as an ‘add–on’ agent in the patients with CKD st. I–III and resistant hypertension. Age ofpatients was 53±5,8 years. Glomerular filtration rate (GFR) before treatment was 68,7±23,0 mL/min/1,73m 2. Before and 3 months after treatment, we determined improvement in the time–frequency analysis of heart rate variability. Results. Following treatment with moxonidine, the SBP significant fell from 153.6±8.1 to 130.7±4.6 mmHg (P< 0.001). The DBP also showed a significant reduction from 96.7±2,4 to 80.9±2,6 mmHg (P< 0.001). Reduction of SBP pressure was 22.9±7.9 mm Hg and reduction of DBP was 15.9±3.1 mm Hg. 29patients (83%) achieved the goal blood pressure – 130/80 mm Hg and less. 5 patients (14%) were not achieve goal blood pressure, but blood pressure lowered <140/90 mm Hg. In 1 patient (3%) blood pressure decreased from 160/100 mm Hg to 145/90 mm Hg. The majority of patients (28 – 80%)

scholarly journals Short-term recovery of heart rate variability and its relationship with blood pressure after different intensity treadmill exercise

2020 ◽  
Author(s):  
Liang Wu ◽  
Ping Shi ◽  
Jiang Shao ◽  
Anan Li ◽  
Hongliu Yu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Treadmill Exercise ◽  
Recovery Period ◽  
Short Term ◽  
Poincaré Plot ◽  
Time Frequency ◽  
Rate Asymmetry ◽  
Heart Rate Asymmetry

Abstract Background : Heart rate variability (HRV) provides an opportunity to capture the tiny but early signs that may predict the future cardiovascular risk in healthy individuals and further, helps understand how well the cardiovascular autonomic system works. Aims of this study were to elucidate short-term recovery of HRV and its relationship with blood pressure recovery after different intensity treadmill exercise. Methods : Fifteen healthy participants performed four different conditions (REST; speed 6km/h; speed 8km/h; speed 10km/h), systolic and diastolic blood pressure per 30s (SBP, DBP) and 5-mins consecutive heart beats intervals were measured after each trial. Autonomic nervous regulation was evaluated using HRV time-frequency domain indices and heart rate asymmetry (HRA) indices. Each index was calculated using 5 mins electrocardiogram (ECG) series and consecutive 30-s windows in 5 mins. Results : the vagally related indices (RMSSD, pNN50 and HF) decreased and the indices representing overall variability (SDNN, LF) had different trends as intensity increasing. The sympathetic-vagal balance parameter LF/HF increased, too. HRV indices had strong correlations with DBP but weak with SBP. Meanwhile, heart rate asymmetry vanished after each trial. Conclusions : The findings suggested a vagal withdrawal as soon as the end of treadmill exercise. It could be concluded that sympathetic modulation was stronger as intensity increasing. During recovery period, DBP was mediated by vagal activation and sympathetic withdrawal. The diminished asymmetry in Poincaré plot was the result of sympathetic acceleration and vagal reduction.

Bifurcation in a Simple Model of the Cardiovascular System

2000 ◽  
Vol 39 (02) ◽  
pp. 118-121 ◽  
Author(s):  
S. Akselrod ◽  
S. Eyal
Keyword(s):  
Nonlinear Dynamics ◽  
Blood Pressure ◽  
Heart Rate ◽  
Fixed Point ◽  
Cardiovascular System ◽  
Modified Model ◽  
Mayer Waves ◽  
Sustained Oscillations ◽  
Human Cardiovascular System ◽  
Physiological Values

Abstract:A simple nonlinear beat-to-beat model of the human cardiovascular system has been studied. The model, introduced by DeBoer et al. was a simplified linearized version. We present a modified model which allows to investigate the nonlinear dynamics of the cardiovascular system. We found that an increase in the -sympathetic gain, via a Hopf bifurcation, leads to sustained oscillations both in heart rate and blood pressure variables at about 0.1 Hz (Mayer waves). Similar oscillations were observed when increasing the -sympathetic gain or decreasing the vagal gain. Further changes of the gains, even beyond reasonable physiological values, did not reveal another bifurcation. The dynamics observed were thus either fixed point or limit cycle. Introducing respiration into the model showed entrainment between the respiration frequency and the Mayer waves.

scholarly journals Differential effects of the blood pressure state on pulse rate variability and heart rate variability in critically ill patients

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Elisa Mejía-Mejía ◽  
James M. May ◽  
Mohamed Elgendi ◽  
Panayiotis A. Kyriacou
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Pulse Rate ◽  
Pulse Transit Time ◽  
Pulse Rate Variability ◽  
Physiological Factors ◽  
Ecg Signals ◽  
Non Invasive ◽  
Electrocardiogram Ecg

AbstractHeart rate variability (HRV) utilizes the electrocardiogram (ECG) and has been widely studied as a non-invasive indicator of cardiac autonomic activity. Pulse rate variability (PRV) utilizes photoplethysmography (PPG) and recently has been used as a surrogate for HRV. Several studies have found that PRV is not entirely valid as an estimation of HRV and that several physiological factors, including the pulse transit time (PTT) and blood pressure (BP) changes, may affect PRV differently than HRV. This study aimed to assess the relationship between PRV and HRV under different BP states: hypotension, normotension, and hypertension. Using the MIMIC III database, 5 min segments of PPG and ECG signals were used to extract PRV and HRV, respectively. Several time-domain, frequency-domain, and nonlinear indices were obtained from these signals. Bland–Altman analysis, correlation analysis, and Friedman rank sum tests were used to compare HRV and PRV in each state, and PRV and HRV indices were compared among BP states using Kruskal–Wallis tests. The findings indicated that there were differences between PRV and HRV, especially in short-term and nonlinear indices, and although PRV and HRV were altered in a similar manner when there was a change in BP, PRV seemed to be more sensitive to these changes.

scholarly journals Ethnic and sex differences in the longitudinal association between heart rate variability and blood pressure

2021 ◽  
pp. 1-7
Author(s):  
LaBarron K. Hill ◽  
Julian F. Thayer ◽  
DeWayne P. Williams ◽  
James D. Halbert ◽  
Guang Hao ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Sex Differences ◽  
Longitudinal Association

scholarly journals Nonlinearities of heart rate variability in animal models of impaired cardiac control: contribution of different time scales

2017 ◽  
Vol 123 (2) ◽  
pp. 344-351 ◽  
Author(s):  
Luiz Eduardo Virgilio Silva ◽  
Renata Maria Lataro ◽  
Jaci Airton Castania ◽  
Carlos Alberto Aguiar Silva ◽  
Helio Cesar Salgado ◽  
...  
Keyword(s):  
Nonlinear Dynamics ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Time Scales ◽  
Multiscale Entropy ◽  
Time Frequency ◽  
Cardiac Control ◽  
Long Time ◽  
Nonlinear Features ◽  
Short Time

Heart rate variability (HRV) has been extensively explored by traditional linear approaches (e.g., spectral analysis); however, several studies have pointed to the presence of nonlinear features in HRV, suggesting that linear tools might fail to account for the complexity of the HRV dynamics. Even though the prevalent notion is that HRV is nonlinear, the actual presence of nonlinear features is rarely verified. In this study, the presence of nonlinear dynamics was checked as a function of time scales in three experimental models of rats with different impairment of the cardiac control: namely, rats with heart failure (HF), spontaneously hypertensive rats (SHRs), and sinoaortic denervated (SAD) rats. Multiscale entropy (MSE) and refined MSE (RMSE) were chosen as the discriminating statistic for the surrogate test utilized to detect nonlinearity. Nonlinear dynamics is less present in HF animals at both short and long time scales compared with controls. A similar finding was found in SHR only at short time scales. SAD increased the presence of nonlinear dynamics exclusively at short time scales. Those findings suggest that a working baroreflex contributes to linearize HRV and to reduce the likelihood to observe nonlinear components of the cardiac control at short time scales. In addition, an increased sympathetic modulation seems to be a source of nonlinear dynamics at long time scales. Testing nonlinear dynamics as a function of the time scales can provide a characterization of the cardiac control complementary to more traditional markers in time, frequency, and information domains. NEW & NOTEWORTHY Although heart rate variability (HRV) dynamics is widely assumed to be nonlinear, nonlinearity tests are rarely used to check this hypothesis. By adopting multiscale entropy (MSE) and refined MSE (RMSE) as the discriminating statistic for the nonlinearity test, we show that nonlinear dynamics varies with time scale and the type of cardiac dysfunction. Moreover, as complexity metrics and nonlinearities provide complementary information, we strongly recommend using the test for nonlinearity as an additional index to characterize HRV.

scholarly journals Heart rate variability and blood pressure among Japanese men and women: a community-based cross-sectional study

2014 ◽  
Vol 37 (8) ◽  
pp. 779-784 ◽  
Author(s):  
Hiromi Mori ◽  
Isao Saito ◽  
Eri Eguchi ◽  
Koutatsu Maruyama ◽  
Tadahiro Kato ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Community Based ◽  
Cross Sectional ◽  
Japanese Men ◽  
Men And Women
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