NONLINEAR INDICES OF HEART RATE VARIABILITY FOR DIFFERENTIATING ARRHYTHMIAS

2013 ◽  
Vol 13 (04) ◽  
pp. 1350061 ◽  
Author(s):  
N. D. ASHA ◽  
K. PAUL JOSEPH
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Normal Sinus Rhythm ◽  
Ventricular Tachyarrhythmia ◽  
Recurrence Plot ◽  
Largest Lyapunov Exponent ◽  
Fluctuation Analysis ◽  
Scaling Exponent ◽  
Poincaré Plot ◽  
Diagonal Length

Heart rate variability (HRV) is the temporal variation between sequences of consecutive heartbeats. Chaos and fractal-based measurements have been widely used for quantifying the HRV for cardiac risk stratification purposes. In this paper, five different sets of HRVs, viz., normal sinus rhythm (NSR), congestive heart failure (CHF), cardiac arrhythmia suppression trial (CAST), supra ventricular tachyarrhythmia (SVTA) and atrial fibrillation (AF), have been analysed using nonlinear parameters to fix the ranges of each parameter. Data were downloaded from the PhysioNet database with 15 sets in each case. The parameters used for analysis were Poincare plot measures: SD1, SD2 and SD12, largest Lyapunov exponent (LLE), correlation dimension (CD); recurrence plot measures: recurrence rate (REC), determinism (DET), mean diagonal length (L mean ), maximal diagonal length (L max ) and entropy (ENTR); detrended fluctuation analysis measures: scaling exponent (α) and fractal dimension (FD); sample entropy (SampEn); and approximate entropy (ApEn). Analysis of variance (ANOVA) was done for confirming the differences in parameter values between various cases. All parameters except LLE showed a significant statistical difference for different cases.

scholarly journals A New Detection Method Defining the Aerobic Threshold for Endurance Exercise and Training Prescription Based on Fractal Correlation Properties of Heart Rate Variability

2021 ◽  
Vol 11 ◽  
Author(s):  
Bruce Rogers ◽  
David Giles ◽  
Nick Draper ◽  
Olaf Hoos ◽  
Thomas Gronwald
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Gas Exchange ◽  
Ventilatory Threshold ◽  
Intraclass Correlation ◽  
Fluctuation Analysis ◽  
Scaling Exponent ◽  
Low Intensity ◽  
Low Intensity Exercise ◽  
Correlation Properties

The short-term scaling exponent alpha1 of detrended fluctuation analysis (DFA a1), a nonlinear index of heart rate variability (HRV) based on fractal correlation properties, has been shown to steadily change with increasing exercise intensity. To date, no study has specifically examined using the behavior of this index as a method for defining a low intensity exercise zone. The aim of this report is to compare both oxygen intake (VO2) and heart rate (HR) reached at the first ventilatory threshold (VT1), a well-established delimiter of low intensity exercise, to those derived from a predefined DFA a1 transitional value. Gas exchange and HRV data were obtained from 15 participants during an incremental treadmill run. Comparison of both VO2 and HR reached at VT1 defined by gas exchange (VT1 GAS) was made to those parameters derived from analysis of DFA a1 reaching a value of 0.75 (HRVT). Based on Bland Altman analysis, linear regression, intraclass correlation (ICC) and t testing, there was strong agreement between VT1 GAS and HRVT as measured by both HR and VO2. Mean VT1 GAS was reached at 39.8 ml/kg/min with a HR of 152 bpm compared to mean HRVT which was reached at 40.1 ml/kg/min with a HR of 154 bpm. Strong linear relationships were seen between test modalities, with Pearson’s r values of 0.99 (p < 0.001) and.97 (p < 0.001) for VO2 and HR comparisons, respectively. Intraclass correlation between VT1 GAS and HRVT was 0.99 for VO2 and 0.96 for HR. In addition, comparison of VT1 GAS and HRVT showed no differences by t testing, also supporting the method validity. In conclusion, it appears that reaching a DFA a1 value of 0.75 on an incremental treadmill test is closely associated with crossing the first ventilatory threshold. As training intensity below the first ventilatory threshold is felt to have great importance for endurance sport, utilization of DFA a1 activity may provide guidance for a valid low training zone.

scholarly journals A Hybrid Signal Processing of RR Intervals from QTc Variation Searching Arrhythmia and Improving Heart Rate Variability Assessment in Acute Large Artery Ischemic Stroke

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
S. Rangsungnoen ◽  
P. Chanbenjapipu ◽  
N. Mathuradavong ◽  
K. Suwanprasert
Keyword(s):  
Heart Rate ◽  
Signal Processing ◽  
Heart Rate Variability ◽  
Acute Stroke ◽  
Sample Entropy ◽  
Scaling Exponent ◽  
Large Artery ◽  
Qrs Detection ◽  
Poincaré Plot ◽  
Mean Heart Rate

Sudden death caused by abnormal QTc and atrial fibrillation (AF) has been reported in stroke. Heart rate variability (HRV) is reduced with missing beats of RRI during arrhythmic episode and abnormal QTc variation during acute stroke. In this study, we develop a hybrid signal processing by Pan Tompkins QRS detection and Kalman filter estimator for meaningful missing beats and searching AF with prolonged QTc. We use this hybrid model to investigate RRIs of Lead II ECG in thirty acute stroke patients with long QTc and AF (LQTc-AF) and normal QTc without AF (NQTc-nonAF) and then assess them by HRV. In LQTc-AF Kalman, higher mean heart rate with lower mean RRIs compared to NQTc-nonAF Kalman was characterized. LQTc-AF Kalman showed significant increase in SDNN, HF, SD2, SD2/SD1, and sample entropy. SDNN and HF associated with high RMSSD, pNN50, and SD1 reflect predominant parasympathetic drive for sympathovagal balance in LQTc-AF Kalman. Greater SD2, SD2/SD1, and sample entropy indicate more scatter of Poincaré plot. Compared with conventional Labchart, fractal scaling exponent of α1 (DFA) is higher in LQTc-AF Kalman. Remarkable complexity with parasympathetic drive in LQTc-AF Kalman suggests an influence of missing beats during stroke.

Sex differences in linear and nonlinear heart rate variability during early recovery from supramaximal exercise

2010 ◽  
Vol 35 (S1) ◽  
pp. 439-446 ◽  
Author(s):  
Goncalo V. Mendonca ◽  
Kevin S. Heffernan ◽  
Lindy Rossow ◽  
Myriam Guerra ◽  
Fernando D. Pereira ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Low Frequency ◽  
Autonomic Response ◽  
Fluctuation Analysis ◽  
Scaling Exponent ◽  
Supramaximal Exercise ◽  
Early Recovery ◽  
Additional Information ◽  
Linear And Nonlinear

Women demonstrate greater RR interval variability than men of similar age. Enhanced parasympathetic input into cardiac regulation appears to be not only greater in women, but also protective during periods of cardiac stress. Even though women may have a more favorable autonomic profile after exercise, little research has been conducted on this issue. This study was designed to examine the cardiac autonomic response, in both male and female participants, during the early recovery from supramaximal exercise. Twenty-five individuals, aged 20 to 33 years (13 males and 12 females), performed a 30-s Wingate test. Beat-to-beat RR series were recorded before and 5 min after exercise, with the participants in the supine position and under paced breathing. Linear (spectral analysis) and nonlinear analyses (detrended fluctuation analysis (DFA)) were performed on the same RR series. At rest, women presented lower raw low frequency (LF) power and higher normalized high frequency (HF) power. Under these conditions, the LF/HF ratio of women was also lower than that of men (p < 0.05), but there were no differences in the short-term scaling exponent (α1). Even though both sexes showed a significant modification in linear and nonlinear measures of heart rate variability (HRV) (p < 0.05), women had a greater change in LF/HF ratio and α1 than men from rest to recovery. This study demonstrates that the cardiac autonomic function of women is more affected by supramaximal exercise than that of men. Additionally, DFA did not provide additional information about sexual dimorphisms, compared with conventional spectral HRV techniques.

scholarly journals Nonlinear Methods Most Applied to Heart-Rate Time Series: A Review

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 309 ◽  
Author(s):  
Teresa Henriques ◽  
Maria Ribeiro ◽  
Andreia Teixeira ◽  
Luísa Castro ◽  
Luís Antunes ◽  
...  
Keyword(s):  
Heart Rate ◽  
Recurrence Plot ◽  
Multiscale Entropy ◽  
Fluctuation Analysis ◽  
Mathematical Methods ◽  
Poincaré Plot ◽  
Nonlinear Methods ◽  
Plot Analysis ◽  
Heart Rate Dynamics ◽  
Recurrence Plot Analysis

The heart-rate dynamics are one of the most analyzed physiological interactions. Many mathematical methods were proposed to evaluate heart-rate variability. These methods have been successfully applied in research to expand knowledge concerning the cardiovascular dynamics in healthy as well as in pathological conditions. Notwithstanding, they are still far from clinical practice. In this paper, we aim to review the nonlinear methods most used to assess heart-rate dynamics. We focused on methods based on concepts of chaos, fractality, and complexity: Poincaré plot, recurrence plot analysis, fractal dimension (and the correlation dimension), detrended fluctuation analysis, Hurst exponent, Lyapunov exponent entropies (Shannon, conditional, approximate, sample entropy, and multiscale entropy), and symbolic dynamics. We present the description of the methods along with their most notable applications.

scholarly journals Prognostic value of heart rate variability in patients with coronary artery disease in the current treatment era

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254107
Author(s):  
Antti O. Vuoti ◽  
Mikko P. Tulppo ◽  
Olavi H. Ukkola ◽  
M. Juhani Junttila ◽  
Heikki V. Huikuri ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Low Frequency ◽  
Frequency Component ◽  
Current Treatment ◽  
Fluctuation Analysis ◽  
Scaling Exponent ◽  
Natural Logarithm ◽  
Artery Disease ◽  
Detrended Fluctuation

Coronary artery disease (CAD) mortality has declined substantially over the past decades thanks to advancing medical and interventional/surgical treatments; therefore, the prognostic value of the heart rate variability in CAD in the current treatment era is not well established. We evaluated the prognostic significance of baseline heart rate variability in 1,757 ARTEMIS study patients with angiographically verified CAD. During an average follow-up time of 8.7 ± 2.2 years, a total of 285 (16.2%) patients died. Of the patients, 63 (3.6%) suffered sudden cardiac death or were resuscitated from sudden cardiac arrest (SCD/SCA), 60 (3.4%) experienced non-sudden cardiac death (NSCD), and death attributable to non-cardiac causes (NCD) occurred in 162 (9.2%) patients. For every 10 ms decrease in standard deviation of normal to normal intervals the risk for SCD/SCA, NSCD and NCD increased significantly: HR 1.153 (95% CI 1.075–1.236, p<0.001), HR 1.187 (95% CI 1.102–1.278, p<0.001) and HR 1.080 (95% CI 1.037–1.125, p<0.001), respectively. The natural logarithm of the low-frequency component of the power spectrum and the short-term scaling exponent of the detrended fluctuation analysis also had significant association with all modes of death (p<0.001). After relevant adjustment, standard deviation of normal-to-normal intervals retained its association with NSCD and NCD (p<0.01), the natural logarithm of the low-frequency component of the power spectrum with all modes of death (p from <0.05 to <0.01), and the short-term scaling exponent of the detrended fluctuation analysis with SCD/SCA (p<0.05) and NCD (p<0.001). In conclusion, impairment of many measures of heart rate variability predicts mortality but is not associated with any specific mode of death in patients with stable CAD during the current treatment era, limiting the clinical applicability of heart rate variability to targeting therapy.

scholarly journals Validation of the Polar RS800CX for assessing heart rate variability during rest, moderate cycling and post-exercise recovery

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1501 ◽  
Author(s):  
Kyriakos I. Tsitoglou ◽  
Yiannis Koutedakis ◽  
Petros C. Dinas
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Recurrence Plot ◽  
Maximal Heart Rate ◽  
Poincaré Plot ◽  
Post Exercise ◽  
Plot Analysis ◽  
Mean Differences ◽  
Post Exercise Recovery ◽  
Electrocardiogram Ecg

Background: Heart rate variability (HRV) is an autonomic nervous system marker that provides reliable information for both disease prevention and diagnosis; it is also used in sport settings. We examined the validity of the Polar RS800CX heart rate monitor during rest, moderate cycling, and recovery in considering the total of 24 HRV indices. Method: A total of 32 healthy males (age=24.78±6.87 years, body mass index=24.48±3.13 kg/m2) completed a session comprised by three 20-minute time periods of resting, cycling at 60% of maximal heart rate, and recovery using a Polar RS800CX and an electrocardiogram (ECG) monitors. The HRV indices included time-domain, frequency-domain, Poincaré plot and recurrence plot. Bland–Altman plot analysis was used to estimate agreement between Polar RS800CX and ECG. Results: We detected significant associations (r>0.75, p<0.05) in all HRV indices, while five out of 24 HRV indices displayed significant mean differences (p<0.05) between Polar RS800CX and ECG during the resting period. However, for the exercise and recovery periods, we found significant mean differences (p<0.05) in 16/24 and 22/24 HRV indices between the two monitors, respectively. Conclusion: It is concluded that Polar RS800CX is a valid tool for monitoring HRV in individuals at resting conditions, but it displays inconsistency when used during exercise at 60% of maximal heart rate and recovery periods.

Non-linear analysis of heart rate variability for evaluating the acute effects of caffeinated beverages in young adults

2020 ◽  
Vol 30 (7) ◽  
pp. 1018-1023 ◽  
Author(s):  
Serife G. Caliskan ◽  
Mehmet D. Bilgin
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Young Adults ◽  
Approximate Entropy ◽  
Energy Drink ◽  
High Rate ◽  
Largest Lyapunov Exponent ◽  
Fluctuation Analysis ◽  
Electrocardiogram Signals ◽  
Non Linear

AbstractCaffeinated beverages are the most consumed substances in the world. High rate of uptake of these beverages leads to various cardiovascular disorders ranging from palpitations to coronary failure. The objective of the study is to ascertain how the complexity parameters of heart rate variability are affected by acute consumption of caffeinated beverages in young adults.Electrocardiogram measurements were performed before consuming drinks. After consuming the drinks, measurements were done again at 30 minutes and 60 minutes. Heart rate variability signals were acquired from electrocardiogram signals. Also, the signals were reconstructed in the phase space and largest Lyapunov exponent, correlation dimension, approximate entropy, and detrended fluctuation analysis values were calculated.Heart rate increased for energy drink and cola groups but not in coffee group. Non-linear parameter values of energy drink, coffee, and cola group are increased within 60 minutes after drink consumption. This change is statistically significant just for energy drink group.Energy drink consumption increases the complexity of the cardiovascular system in young adults significantly. Coffee and cola consumption have no significant effect on the non-linear parameters of heart rate variability.

scholarly journals Heart Rate n-Variability (HRnV): A Novel Representation of Beat-to-Beat Variation in Electrocardiogram

2018 ◽  
Author(s):  
Nan Liu ◽  
Dagang Guo ◽  
Zhi Xiong Koh ◽  
Andrew Fu Wah Ho ◽  
Marcus Eng Hock Ong
Keyword(s):  
Heart Rate ◽  
Normal Sinus Rhythm ◽  
Noise Removal ◽  
Fluctuation Analysis ◽  
Poincaré Plot ◽  
Normal Sinus ◽  
Cardiac Autonomic Regulation ◽  
Important Addition ◽  
The Time Domain ◽  
Electrocardiogram Ecg

AbstractHeart rate variability (HRV) is a widely adopted tool for evaluating changes in cardiac autonomic regulation. The majority of efforts have focused on developing methods to assess HRV by deriving sophisticated parameters with linear and nonlinear techniques and adopting advanced signal processing tools for efficient noise removal and accurate QRS detection. In this paper, we propose a novel representation of beat-to-beat variation in an electrocardiogram (ECG), called heart rate n-variability (HRnV), as an alternative to conventional HRV measures. We derived two novel HRnV measures based on non-overlapped and overlapped RR intervals. We also conducted a simulation study by using an ECG record from the MIT-BIH Normal Sinus Rhythm Database to demonstrate the feasibility of calculating HRnV parameters. Among the time domain parameters, we observed that the values were generally incremental with the increase in n. We observed the same trend of changes for the frequency domain parameters. In the nonlinear analysis, the differences between HRV and HRnV from Poincare plot measures were obvious, while those from entropy and detrended fluctuation analysis metrics were not. HRnV measures enable us to augment conventional HRV measures with additional parameters. Although issues remain to be addressed regarding HRnV, we hope to stimulate a new stream of research on this new representation of HRV. HRnV is an important addition to HRV and will contribute to extending the landscape of current studies on HRV.

scholarly journals Heart Rate Variability Monitoring during Interferential Current Application in the Lower Back Area: A Cross-Sectional Study

2021 ◽  
Vol 18 (7) ◽  
pp. 3394
Author(s):  
Blanca De-la-Cruz-Torres ◽  
Eva Martínez-Jiménez ◽  
Emmanuel Navarro-Flores ◽  
Patricia Palomo-López ◽  
Vanesa Abuín-Porras ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Placebo Group ◽  
Intervention Group ◽  
Lumbar Pain ◽  
Poincaré Plot ◽  
Current Application ◽  
Cross Sectional ◽  
Vasovagal Reactions ◽  
Interferential Current

Vasovagal reactions may occur occasionally during electrical stimulation using interferential current (IFC). The purpose of this study was to examine variations in autonomic activity during the application of IFC in asymptomatic participants by analysis of their heart rate variability (HRV). Seventy-three male volunteers were randomly assigned to a placebo group (n = 36; HRV was documented for 10 min, both at rest and during a placebo intervention) and an intervention group (n = 37; HRV was documented for 10 min in two conditions labelled as (1) rest and (2) application of IFC technique on the lumbar segment). The diameters of the Poincaré plot (SD1, SD2), stress score (SS), and the ratio between sympathetic and parasympathetic activity (S/PS) were measured. After interventions, differences amongst the placebo group and the IFC group were found in SD2 (p < 0.001), SS (p = 0.01) and S/PS ratio (p = 0.003). The IFC technique was associated with increased parasympathetic modulation, which could induce a vasovagal reaction. Monitorization of adverse reactions should be implemented during the application of IFC technique. HRV indicators might have a part in prevention of vasovagal reactions. Further studies in patients with lumbar pain are needed to explore possible differences in HRV responses due to the presence of chronic pain.

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