scholarly journals Heart Rate Variability Assessment Using Time–Frequency Analysis in Hypotensive and Non-Hypotensive Patients in Hemodialysis

2020 ◽  
Vol 10 (17) ◽  
pp. 6074
Author(s):  
Brayans Becerra-Luna ◽  
Raúl Cartas-Rosado ◽  
Juan Carlos Sánchez-García ◽  
Raúl Martínez-Memije ◽  
Oscar Infante-Vázquez ◽  
...  

Intradialytic hypotension occurs in 10–30% of hemodialysis (HD) sessions. This phenomenon affects the cardiovascular system’s functions, which are reflected in the activity of the autonomic nervous system (ANS). To indirectly assess the ANS during HD, we analyzed the mean R–R intervals and the spectral power of heart rate variability (HRV) from 20 end-stage renal disease patients divided into hypotensive and non-hypotensive groups. The spectrotemporal analysis was accomplished using short-time Fourier transform with 10 min epochs of HRV overlapping by 40%. The spectral power was divided into three segments according to high frequency, low frequency, and very low frequency bandwidths and averaged to fit quadratic regression models. The analysis of the mean R–R intervals showed significant differences between the groups (p = 0.029). The power variation over time was significant in each spectral band (p ≪ 0.05). The average power, maximum power, and time when the peak was reached differed for each band and between groups, showing the ability to correctly identify the decompensation of the ANS and discriminate between hypotensive and non-hypotensive patients. Additionally, the changes in the sympathovagal ratio were not significant and very scattered for the hypotensive group (p = 0.23) compared to the non-hypotensive group, where the changes were significant (p ≪ 0.05) and much less scattered.

2021 ◽  
Vol 29 (3) ◽  
pp. 369-378
Author(s):  
Aleksej A. Nizov ◽  
Aleksej I. Girivenko ◽  
Mihail M. Lapkin ◽  
Aleksej V. Borozdin ◽  
Yana A. Belenikina ◽  
...  

BACKGROUND: The search for rational methods of primary, secondary, and tertiary prevention of coronary heart disease. To date, there are several publications on heart rate variability in ischemic heart disease. AIM: To study the state of the regulatory systems in the organism of patients with acute coronary syndrome without ST segment elevation based on the heart rhythm, and their relationship with the clinical, biochemical and instrumental parameters of the disease. MATERIALS AND METHODS: The open comparative study included 76 patients (62 men, 14 women) of mean age, 61.0 0.9 years, who were admitted to the Emergency Cardiology Department diagnosed of acute coronary syndrome without ST segment elevation. On admission, cardiointervalometry was performed using Varicard 2.51 apparatus, and a number of clinical and biochemical parameters were evaluated RESULTS: Multiple correlations of parameters of heart rate variability and clinical, biochemical and instrumental parameters were observed. From this, a cluster analysis of cardiointervalometry was performed, thereby stratifying patients into five clusters. Two extreme variants of dysregulation of the heart rhythm correlated with instrumental and laboratory parameters. A marked increase in the activity of the subcortical nerve centers (maximal increase of the spectral power in the very low frequency range with the underlying reduction of SDNN) in cluster 1 was associated with reduction of the left ventricular ejection fraction: cluster 147.0 [40.0; 49.0], cluster 260.0 [58.0; 64.0], cluster 360.0 [52.5; 64.5] % (the data are presented in the form of median and interquartile range; Me [Q25; Q75], p 0,05). Cluster 5 showed significant reduction in SDNN (monotonous rhythm), combined with increased level of creatine phosphokinase (CPC): cluster 5446,0 [186.0; 782.0], cluster 4141.0 [98.0; 204.0] IU/l; Me [Q25; Q75], p 0.05) and MВ-fraction of creatine phosphokinase; cluster 532.0 [15.0; 45.0], 4 cluster 412.0 [9.0; 18.0] IU/l; Me [Q25; Q75], p 0.05). CONCLUSIONS: In patients with acute coronary syndrome without ST segment elevation, cluster analysis of parameters of heart rate variability identified different peculiarities of regulation of the heart rhythm. Pronounced strain of the regulatory systems of the body was found to be associated with signs of severe pathology: the predominance of VLF (spectral power of the curve enveloping a dynamic range of cardiointervals in the very low frequency range) in spectral analysis with an underlying reduced SDNN is characteristic of patients with a reduced ejection fraction, and a monotonous rhythm is characteristic of patients with an increased level of creatine phosphokinase and MB-fraction of creatine phosphokinase.


2017 ◽  
Vol 27 (9) ◽  
pp. 1662-1669 ◽  
Author(s):  
Cagdas Vural ◽  
Ener Cagri Dinleyici ◽  
Pelin Kosger ◽  
Ozge Bolluk ◽  
Zubeyir Kilic ◽  
...  

AbstractIntroductionCarbon monoxide poisoning may cause myocardial toxicity and cardiac autonomic dysfunction, which may contribute to the development of life-threatening arrhythmias. We investigated the potential association between acute carbon monoxide exposure and cardiac autonomic function measured by heart rate variability.MethodThe present study included 40 children aged 1–17 years who were admitted to the Pediatric Intensive Care Unit with acute carbon monoxide poisoning and 40 healthy age- and sex-matched controls. Carboxyhaemoglobin and cardiac enzymes were measured at admission. Electrocardiography was performed on admission and discharge, and 24-hour Holter electrocardiography was digitally recorded. Heart rate variability was analysed at both time points – 24-hour recordings – and frequency domains – from the first 5 minutes of intensive care unit admission.ResultsTime domain and frequency indices such as high-frequency spectral power and low-frequency spectral power were similar between patient and control groups (p>0.05). The ratio of low-frequency spectral power to high-frequency spectral power was significantly lower in the carbon monoxide poisoning group (p<0.001) and was negatively correlated with carboxyhaemoglobin levels (r=−0.351, p<0.05). The mean heart rate, QT dispersion, corrected QT dispersion, and P dispersion values were higher in the carbon monoxide poisoning group (p<0.05) on admission. The QT dispersion and corrected QT dispersion remained longer in the carbon monoxide poisoning group compared with controls on discharge (p<0.05).ConclusionThe frequency domain indices, especially the ratio of low-frequency spectral power to high-frequency spectral power, are useful for the evaluation of the cardiac autonomic function. The decreased low-frequency spectral power-to-high-frequency spectral power ratio reflects a balance of the autonomic nervous system, which shifted to parasympathetic components.


1995 ◽  
Vol 82 (3) ◽  
pp. 609-619 ◽  
Author(s):  
Hans-Bernd Hopf ◽  
Andreas Skyschally ◽  
Gerd Heusch ◽  
Jurgen Peters

Background Heart rate variability in the frequency domain has been proposed to reflect cardiac autonomic control. Therefore, measurement of heart rate variability may be useful to assess the effect of epidural anesthesia on cardiac autonomic tone. Accordingly, the effects of preganglionic cardiac sympathetic blockade by segmental epidural anesthesia were evaluated in humans on spectral power of heart rate variability. Specifically, the hypothesis that cardiac sympathetic blockade attenuates low-frequency spectral power, assumed to reflect cardiac sympathetic modulation, was tested. Methods Ten subjects were studied while supine and during a 15-min 40 degrees head-up tilt both before and after cardiac sympathetic blockade by segmental thoracic epidural anesthesia (sensory block: C6-T6). ECG, arterial pressure, and respiratory excursion (Whitney gauge) were recorded, and a fast-Fourier-transformation was applied to 512-s data segments of heart rate derived from the digitized ECG at the end of each intervention. Results With cardiac sympathetic blockade alone and the subjects supine, both low-frequency (LF, 0.06-0.15 Hz) and high-frequency (HF, 0.15-0.80 Hz) spectral power remained unchanged. During tilt, epidural anesthesia attenuated the evoked increase in heart rate (+11.min-1 +/- 7 SD vs. +6 +/- 7, P = 0.024). However, while during tilt cardiac sympathetic blockade significantly decreased the LF/HF ratio (3.68 +/- 2.52 vs. 2.83 +/- 2.15, P = 0.041 vs. tilt before sympathetic blockade), a presumed marker of sympathovagal interaction, absolute and fractional LF and HF power did not change. Conclusions Although preganglionic cardiac sympathetic blockade reduced the LF/HF ratio during tilt, it did not alter spectral power in the LF band during rest or tilt. Accordingly, low-frequency spectral power is unlikely to specifically reflect cardiac sympathetic modulation in humans.


2015 ◽  
Vol 24 (2) ◽  
pp. 118-127 ◽  
Author(s):  
Muna H. Hammash ◽  
Debra K. Moser ◽  
Susan K. Frazier ◽  
Terry A. Lennie ◽  
Melanie Hardin-Pierce

BackgroundWeaning from mechanical ventilation to spontaneous breathing is associated with changes in the hemodynamic and autonomic nervous systems that are reflected by heart rate variability. Although cardiac dysrhythmias are an important manifestation of hemodynamic alterations, the impact of heart rate variability on the occurrence of dysrhythmias during weaning has not been specifically studied.ObjectivesTo describe differences in heart rate variability spectral power and occurrence of cardiac dysrhythmias at baseline and during the initial trial of weaning from mechanical ventilation and to evaluate the impact of heart rate variability during weaning on occurrence of dysrhythmias.MethodContinuous 3-lead electrocardiographic recordings were collected from 35 patients receiving mechanical ventilation for 24 hours at baseline and during the initial weaning trial. Heart rate variability was evaluated by using spectral power analysis.ResultsLow-frequency power increased (P = .04) and high-frequency and very-low-frequency power did not change during weaning. The mean number of supraventricular ectopic beats per hour during weaning was higher than the mean at baseline (P &lt; .001); the mean of ventricular ectopic beats did not change. Low-frequency power was a predictor of ventricular and supraventricular ectopic beats during weaning (P &lt; .001). High-frequency power was predictive of ventricular and supraventricular (P = .02) ectopic beats during weaning. Very-low-frequency power was predictive of ventricular ectopic beats (P &lt; .001) only.ConclusionHeart rate variability power spectra during weaning were predictive of dysrhythmias. (American Journal of Critical Care. 2015;24:118–127)


2020 ◽  
Vol 32 (02) ◽  
pp. 2050014
Author(s):  
M. Kumar ◽  
D. Singh ◽  
K. K. Deepak

This study identifies a correlation between low-frequency heart rate variability (LF-HRV) and encephalographic (EEG) complexity to differentiate internally operative attention (INT) and externally operative attention (EXT). Electrophysiological fluctuations in response to Posner’s spatial orienting paradigm were explored in 14 healthy volunteers who participated in 6 alternating sessions of attention tasks. HRV analysis was used to measure heart rate fluctuations, and approximate entropy (ApEn) was used to measure changes in the irregularity of EEG and HRV. Power spectral analysis of HRV revealed that there was found to be a significant difference between INT and EXT for HRV-low frequency (HRV-LF) and LH/HF ratio. ApEn for RR-interval time series increased for both attention tasks as compared to baseline and recovery session. The relationship between HRV-LF and EEG spectral power measured at F4 revealed significant negative correlation during ([Formula: see text], with [Formula: see text]) EXT than ([Formula: see text], with [Formula: see text]) INT. Furthermore, a significant positive correlation, yet of moderate strength was noted between HRV-LF and ApEn of EEG signal measured at POz ([Formula: see text], with [Formula: see text]) during EXT as compared to INT ([Formula: see text], with [Formula: see text]) and, a significant negative correlation was observed between ApEn of RR-interval and ApEn of EEG signal measured at POz ([Formula: see text], with [Formula: see text]) during EXT as compared to INT ([Formula: see text], with [Formula: see text]). Thus, it is evident that EXT leads to more irregularity in parietal regions of the brain than the INT. During EXT, the irregularity over the parietal region linked to increased sympathetic activity as compared to INT and corresponds to decreased heart rate. These results may benefit in designing robust human-computer interfaces and accelerated training paradigm to raise an athlete’s performance.


2016 ◽  
Vol 50 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Lukas Cipryan

AbstractThe primary aim of this study was to assess the retest stability of the short-term heart rate variability (HRV) measurement performed within one session and without the use of any intervention. Additionally, a precise investigation of the possible impact of intrinsic biological variation on HRV reliability was also performed. First, a single test-retest HRV measurement was conducted with 20-30 min apart from one another. Second, the HRV measurement was repeated in ten non-interrupted consecutive intervals. The lowest typical error (CV = 21.1%) was found for the square root of the mean squared differences of successive RR intervals (rMSSD) and the highest for the low frequency power (PLF) (CV = 93.9%). The standardized changes in the mean were trivial to small. The correlation analysis revealed the highest level for ln rMSSD (ICC = 0.87), while ln PLF represented the worst case (ICC = 0.59). The reliability indices for ln rMSSD in 10 consecutive intervals improved (CV = 9.9%; trivial standardized changes in the mean; ICC = 0.96). In conclusion, major differences were found in the reliability level between the HRV indices. The rMSSD demonstrated the highest reliability level. No substantial influence of intrinsic biological variation on the HRV reliability was observed.


2007 ◽  
Vol 102 (3) ◽  
pp. 1057-1064 ◽  
Author(s):  
Maya David ◽  
Michael Hirsch ◽  
Jacob Karin ◽  
Eran Toledo ◽  
Solange Akselrod

In this study we present a noninvasive method that enables the investigation of the fetal heart rate (FHR) fluctuations. The objective was to design a quantitative measurement to assess the fetal autonomic nervous system and to investigate its development as a function of the gestational age. Our Medical Physics group has developed a complex algorithm for online beat-to-beat detection of the fetal ECG (FECG), extracted from the maternal abdominal ECG signal. We used our previously acquired FECG data, which includes noninvasive recordings of 200 maternal abdominal ECG signals. From these, we chose 35 cases of healthy pregnancies that we divided into three groups according to gestational age: Group 1, 23 ± 2 wk; Group 2, 32 ± 1 wk; and Group 3, 39 ± 1 wk. The FHR variability was analyzed by a time-frequency decomposition based on a continuous wavelet transform. We showed that, independent of the gestational age, most of the FHR power is concentrated in the very-low-frequency range (0.02–0.08 Hz) and in the low-frequency range (0.08–0.2 Hz). In addition, there is power in the high-frequency range that correlates with the frequency range of fetal respiratory motion (0.4–1.7 Hz). In the intermediate-frequency range (0.2–0.4 Hz), the power is significantly smaller. The changes in the average power spectrum in relation to gestation time were carefully and quantitatively examined. The results imply that there is a neural organization during the last trimester of the pregnancy, and the sympathovagal balance is reduced with the gestational age.


Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Rosangela Hoshi ◽  
Paulo A LOTUFO ◽  
Itamar S Santos ◽  
Alessandra C Goulart ◽  
Jose-Geraldo Mill ◽  
...  

Background: Both conditions as a more width common carotid artery intima-media thickness (cIMT), and a low heart rate variability (HRV) have been associated with cardiovascular health-adverse outcomes. Although previous studies have somehow explored the relationship between these markers, they have not credited the influences exerted by factors such as aging, demographics, and lifestyle variables. Aim: to investigate whether cardio autonomic alterations are accompanied or not by subclinical atherosclerosis, in apparently healthy men and women aged 35 to 74 years-old examined at the baseline of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Methods: The Heart Rate Variability was evaluated on 5-min segments of beat-to-beat heart rate recordings using linear time and frequency domain analyses. The c-IMT images were performed using a Toshiba (Aplio XG™) with a 7.5 MHz linear transducer. The c-IMT was measured in the outer wall during three cardiac cycles. The images were analyzed with specific software (MIA™, Coralville, IA). For this study, c-IMT was defined as the average between the mean left and mean right c-IMT values, and it was analyzed as a continuous and categorized variable (P<75 or P >= 75). Multiple linear models using continuous variables and multivariate logistic regression with categorized cIMT and HRV quartiles were performed. Results: Out of 7,201 participants eligible for analyses, 1,685 (23.4%) presented cIM >= 75th percentile. We found significantly reduced HRV variables in subjects with cIMT>=P75 in comparison to those with cIMT<P75: standard deviation of NN interval (SDNN) 33.0 ms vs. 37.0ms( P< 0.001); root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD) 22.0 ms vs. 26.0ms (P< 0.001); Low-Frequency 191.0ms 2 vs. 260.0ms 2 ( P< 0.001); High-Frequency 164.0 ms 2 vs. 238.5ms 2 ( P< 0.001). In a crude analysis, an increased Odds Ratio (OR)and 95% Confidence Intervals for cIMT >=P75 was verified within the lowest two quartiles of Low-Frequency:1st quartile, OR = 1.75 (95%CI: 1.39 to 2.19); 2nd quartile, OR= 1.53 (1.25 to 1.87).The same was observed for High-Frequency:1st quartile, OR = 1.94 (1.38 to 2.73); 2nd quartile, OR= 1.60 (1.20 to 2.15). However, those associations did not remain after adjustments for anthropometric and clinical variables for Low-Frequency (1st quartile, OR= 1.08 (0.83 to 1.40); 2nd quartile, OR= 1.22 (0.97 to1.55), and for High Frequency, 1st quartile, OR= 1.16 (0.77 to 1.73); 2nd quartile, OR= 1.17 (0.83 to 1.64). Conclusions: Subjects with cIMT greater or equal to 75th percentile presented lower HRV values. However, no independent relationships were detected between cIMT and HRV after multivariate adjustment, suggesting that they may assess different and complementary domains and provide relevant, useful, and non-redundant information of cardiovascular risk.


Author(s):  
Samruddhi Chintaman Vyas ◽  
A. Mooventhan ◽  
N. K. Manjunath

AbstractBackgroundThough hot arm and foot bath (HAFB) is widely used, a precise physiological response is not reported. Hence, the present study was conducted to evaluate the effect of HAFB on heart rate variability (HRV) and blood pressure (BP) in healthy volunteers.Materials and MethodsSixteen healthy male volunteers’ aged 23.81 ± 5.27 (mean ± standard deviation) years were recruited. All the subjects underwent only one session of HAFB (104-degree Fahrenheit) for the duration of 20 min. Assessments such as Electrocardiography and BP were taken before and after the intervention.ResultsResults of this study showed a significant reduction in systolic-BP (SBP), diastolic-BP (DBP), mean arterial pressure (MAP), the mean of the intervals between adjacent QRS complexes or the instantaneous heart rate (RR interval), the number of interval differences of successive NN intervals greater than 50 ms (NN50), the proportion derived by dividing NN50 by the total number of NN intervals (pNN50), and high frequency (HF) band of HRV along with a significant increase in heart rate (HR), low-frequency (LF) band of HRV and LF/HF ratio compared to its baseline.ConclusionsResults of this study suggest that 20 min of HAFB produce a significant increase in HR and a significant reduction in SBP, DBP, and MAP while producing parasympathetic withdrawal.


2019 ◽  
Vol 127 (2) ◽  
pp. 320-327 ◽  
Author(s):  
Binbin Liu ◽  
Saisai Yan ◽  
Xiaoni Wang ◽  
Lin Xie ◽  
Jie Tong ◽  
...  

Frequency domain analysis of heart rate variability (HRV) is a noninvasive method to evaluate the autonomic nervous system (ANS), but the traditional parameters of HRV, i.e., the power spectra of the high-frequency (HF) and low-frequency bands (LF), cannot estimate the activity of the parasympathetic (PNS) and sympathetic nervous systems (SNS) well. The aim of our study was to provide a corrected method to better distinguish the contributions of the PNS and SNS in the HRV spectrum. Respiration has a gating effect on cardiac vagal efferent activity, which induces respiration-locked heart rate (HR) changes because of the fast effect of the PNS. So the respiration-related heart rate (HRr) is closely related to PNS activity. In this study, HR was decomposed into HRr and the respiration-unrelated component (HRru) based on empirical mode decomposition (EMD) and the relationship between HR and respiration. Time-frequency analysis of HRr and HRru was defined as HFr and LFru, respectively, with specific adaptive bands for every signal. Two experimental data sets, representing SNS and PNS activation, respectively, were used for efficiency analysis of our method. Our results show that the corrected HRV predicted ANS activity well. HFr could be an index of PNS activity, LFru mainly reflected SNS activity, and LFru/HFr could be more accurate in representing the sympathovagal balance. NEW & NOTEWORTHY This study includes the time-varying relationship between respiration and heart rate in the analysis of heart rate variability. Correction for low-frequency and high-frequency components based on respiration significantly improved evaluation of the sympathetic and parasympathetic nervous systems.


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