scholarly journals Heart rate variability before and after 14 weeks of training in Thoroughbred horses and Standardbred trotters with different training experience

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0259933
Author(s):  
Zsófia Nyerges-Bohák ◽  
Krisztina Nagy ◽  
László Rózsa ◽  
Péter Póti ◽  
Levente Kovács

Changes in heart rate and heart rate variabilty (HRV) were investigated in untrained (UT; starting their first racing season) and detrained (DT; with 1–3 years of race experience) racehorses before and after 14-week conventional training. HRV was measured at rest over 1 h between 9:00 and 10:00 AM on the usual rest day of the horses. The smallest worthwhile change (SWC) rate was calculated for all HRV parameters. UT horses had significantly higher heart rate compared to DT (P<0.001). There were no gender- or training-related differences in heart rate. The root-mean-square of successive differences (rMSSD) in the consecutive inter-beat-intervals obtained after the 14-week training period was lower compared to pre-training rMSSD (P<0.001). The rMSSD was not influenced by breed, age or gender. In DT horses, there was a significant decrease in the high frequency (HF) component of HRV (P≤0.05) as the result of the 14-week training. These results may reflect saturation of high-frequency oscillations of inter-beat intervals rather than the reduction in parasympathetic influence on the heart. The HF did not differ significantly between the two measurements in UT horses; however, 16.6% of the animals showed a decrease in HF below SWC (P≤0.05). This supports the likelihood of parasympathetic saturation. Although no significant decrease in heart rate was found for the post-training, 30.0% of DT and 58.3% of UT horses still showed a decrease in heart rate below the SWC. Also by individual examination, it was also visible that despite significant post-training decrease in rMSSD, 1 (4.6%) DT and 2 (6.7%) UT horses reached SWC increase in rMMSD. In the case of these horses, the possibility of maladaptation should be considered. The present results indicate that similar to as found in human athletes, cardiac ANS status of racehorses also changes during the physiological adaptation to training. To explore more precise links between HRV and training effectiveness in horses, a more frequent recording would be necessary. Detailed analysis of HRV parameters based on SWC will be able to highlight the importance of fitness evaluation at individual level.

2011 ◽  
Vol 26 (S2) ◽  
pp. 147-147
Author(s):  
T. Diveky ◽  
D. Kamaradova ◽  
A. Grambal ◽  
K. Latalova ◽  
J. Prasko ◽  
...  

The aim of our study is to measure very low frequency band (VLF), low frequency band (LF) and high frequency band (HF) components of R-R interval during orthostatic experiment in panic disorder patients before and after treatment.MethodsWe assessed heart rate variability in 19 patients with panic disorder before and after 6-weeks treatment with antidepressants combined with CBT and 18 healthy controls. They were regularly assessed on the CGI, BAI and BDI. Heart rate variability was assessed during 5 min standing, 5 min supine and 5 min standing positions before and after the treatment. Power spectra were computed using a fast Fourier transformation for very low frequency - VLF (0.0033 - 0.04 Hz), low-frequency - LF (0.04-0.15 Hz) and high frequency - HF (0.15-0.40 Hz) powers.Results19 panic disorder patients entered a 6-week open-label treatment study with combination of SSRI and cognitive behavioral therapy. A combination of CBT and pharmacotherapy proved to be the effective treatment of patients. They significantly improved in all rating scales. There were highly statistical significant differences between panic patients and control group in all components of power spectral analysis in 2nd and in two component of 3rd (LF and HF in standing) positions. There was also statistically significant difference between these two groups in LF/HF ratio in supine position (2nd). During therapy there was tendency to increasing values in all three positions in components of HRV power spectra, but there was only statistically significant increasing in HF1 component.Supported by project IGA MZ ČR NS 10301-3/2009


2020 ◽  
Author(s):  
Elliot H. Smith ◽  
Edward M. Merricks ◽  
Jyun-You Liou ◽  
Camilla Casadei ◽  
Lucia Melloni ◽  
...  

ABSTRACTHigh frequency oscillations (HFOs) recorded from intracranial electrodes during epileptiform discharges are a proposed biomarker of epileptic brain tissue and may also be useful for seizure forecasting, with mixed results. Despite such potential for HFOs, there is limited investigation into the spatial context of HFOs and their relationship to simultaneously recorded neuronal activity. We sought to further understand the biophysical underpinnings of ictal HFOs using unit recordings in the human neocortex and mesial temporal lobe during rhythmic onset seizures. We compare features of ictal discharges in both the seizure core and penumbra (spatial seizure domains defined by multiunit activity patterns). We report differences in spectral features, unit-local field potential coupling, and information theoretic characteristics of HFOs before and after local seizure invasion. Furthermore, we tie these timing-related differences to spatial domains of seizures, showing that penumbral discharges are widely distributed and less useful for seizure localization.


2018 ◽  
Vol 64 (1) ◽  
pp. 99-109
Author(s):  
Bruno T. Campos ◽  
Eduardo M. Penna ◽  
João G.S. Rodrigues ◽  
Mateus Diniz ◽  
Thiago T. Mendes ◽  
...  

Abstract Judo is a high-intensity intermittent combat sport which causes cardiac adaptations both morphologically and related to the autonomic nervous system (ANS). Therefore, this study aims to verify the correlation between heart rate variability (HRV) at rest with performance in the Special Judo Fitness Test (SJFT) and whether groups with different RR values at rest show different performance in the SJFT and during post-test recovery. Sixteen judo athletes with 7.2 ± 3.9 years of training experience participated in the study. Before and after the SJFT execution HRV and lactate measurements were conducted. For HRV analysis, we used the mean interval RR, the standard deviation of the RR interval (SDNN), the root mean square of successive differences in RR intervals (RMSSD), the low frequency (LF) and high frequency (HF) in normalized and absolute units. The sample was split into two groups (low RR and high RR) to verify if this variable could differentiate between specific performance. For the SDNN, a significant and moderate correlation (r = 0.53) was found with the total number of throws and throws in the series A (r = 0.56) and B (r = 0.54) and for the RMSSD a correlation with throws during series B (r = 0.59) in the SJFT. However, the groups did not differ in performance and recovery. Therefore, HRV is related to intermittent judo performance; however, it cannot differentiate between judokas at different levels of performance.


2009 ◽  
pp. 57-67
Author(s):  
G Raffai ◽  
C Csekő ◽  
L Kocsis ◽  
L Dézsi ◽  
E Monos

Microgravity or simulated microgravity induces acute and chronic cardiovascular responses, whose mechanism is pivotal for understanding of physiological adaptation and pathophysiological consequences. We investigated hemodynamic responses of conscious Wistar rats to 45º head-down tilt (HDT) for 7 days. Arterial blood pressure (BP) was recorded by telemetry. Heart rate (HR), spectral properties and the spontaneous baroreflex sensitivity (sBRS) were calculated. Head-up tilt (HUT) was applied for 2 h before and after HDT to assess the degree of any possible cardiovascular deconditioning. Horizontal control BP and HR were 112.5±2.8 mmHg and 344.7±10 bpm, respectively. HDT elicited an elevation in BP and HR by 8.3 % and 8.8 %, respectively, in less than 1 h. These elevations in BP and HR were maintained for 2 and 3 days, respectively, and then normalized. Heart rate variability was unchanged, while sBRS was permanently reduced from the beginning of HDT (1.01±0.08 vs. 0.74±0.05 ms/mmHg). HUT tests before and after HDT resulted in BP elevations (6.9 vs. 11.6 %) and sBRS reduction (0.44 vs. 0.37 ms/mmHg), respectively. The pressor response during the post-HDT HUT test was accompanied by tachycardia (13.7 %). In conclusion, chronic HDT does not lead to symptoms of cardiovascular deconditioning. However the depressed sBRS and tachycardic response seen during the post-HDT HUT test may indicate disturbances in cardiovascular control.


Author(s):  
Мартынов ◽  
Ilya Martynov

The article deals with the informative content of spectral analysis of heart rate variability in the assessment of the regulatory impacts on the systemic hemodynamics during orthostatic test. It was observed that the patients who suffer from neurogenic syncope already at a young age had had a decrease in low frequency oscillations, as well as a decrease in peripheral vascular resistance during the test. It allows us to make a conclusion about the sympathetic vasomotor regulation dysfunction, even before the symptoms of orthostatic hypotension were evident. The decrease in the tonic vagal effect which follows from the depression of high-frequency oscillations, makes for increasing the chronotropic function of the heart and keeps a relative sympathetic predominance in order to maintain adequate level of blood pressure


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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Elliot H. Smith ◽  
Edward M. Merricks ◽  
Jyun-You Liou ◽  
Camilla Casadei ◽  
Lucia Melloni ◽  
...  

Abstract High frequency oscillations (HFOs) are bursts of neural activity in the range of 80 Hz or higher, recorded from intracranial electrodes during epileptiform discharges. HFOs are a proposed biomarker of epileptic brain tissue and may also be useful for seizure forecasting. Despite such clinical utility of HFOs, the spatial context and neuronal activity underlying these local field potential (LFP) events remains unclear. We sought to further understand the neuronal correlates of ictal high frequency LFPs using multielectrode array recordings in the human neocortex and mesial temporal lobe during rhythmic onset seizures. These multiscale recordings capture single cell, multiunit, and LFP activity from the human brain. We compare features of multiunit firing and high frequency LFP from microelectrodes and macroelectrodes during ictal discharges in both the seizure core and penumbra (spatial seizure domains defined by multiunit activity patterns). We report differences in spectral features, unit-local field potential coupling, and information theoretic characteristics of high frequency LFP before and after local seizure invasion. Furthermore, we tie these time-domain differences to spatial domains of seizures, showing that penumbral discharges are more broadly distributed and less useful for seizure localization. These results describe the neuronal and synaptic correlates of two types of pathological HFOs in humans and have important implications for clinical interpretation of rhythmic onset seizures.


1991 ◽  
Vol 260 (3) ◽  
pp. H985-H988 ◽  
Author(s):  
D. C. Randall ◽  
D. R. Brown ◽  
R. M. Raisch ◽  
J. D. Yingling ◽  
W. C. Randall

The purpose of this study was to quantify the relative roles of the canine cardiac parasympathetic and sympathetic nerves in controlling the distribution of power within the heart rate (HR) power spectrum using a highly selective surgical technique to parasympathectomize the SA node. DAta were recorded in awake dogs (n = 6) before and after the selective denervation; the animals were isolated from human contact and their behavior carefully monitored during the measurements. The average amplitude in the high-frequency (approximately 0.32 Hz) peak in the HR power spectrum decreased from a predenervation control of 2.68 +/- 1.54 (mean +/- SD, arbitrary units) to 0.07 +/- 0.06 (P less than 0.05). Corresponding resting HR increased from 80 +/- 9 to 106 +/- 16 beats/min (P less than 0.05). The low-frequency peak (approximately 0.02 Hz) also decreased from a control of 2.45 +/- 1.18 to a postparasympathectomy value of 1.25 +/- 0.92 (P less than 0.05). beta-Adrenergic blockade (propranolol, 1 mg/kg) further decreased the latter peak to 0.59 +/- 0.52 (P less than 0.05). These data directly demonstrate that the high-frequency peak of the HR power spectrum 1) results from parasympathetic control of SA nodal automaticity, while 2) the low-frequency peak reflects activity in both divisions of the autonomic nervous system.


Author(s):  
Elliot H. Smith ◽  
Edward M. Merricks ◽  
Jyun-You Liou ◽  
Camilla Casadei ◽  
Lucia Melloni ◽  
...  

ABSTRACTObjectiveHigh frequency oscillations (HFOs) recorded from intracranial electrodes during epileptiform discharges have been proposed as a biomarker of epileptic brain sites and may also be a useful feature for seizure forecasting, with mixed results. Currently, pathological subclasses of HFOs have been defined primarily by frequency characteristics. Despite this, there has been limited investigation into the spatial context of HFOs with recruitment of local cortex into seizure discharging. We sought to further understand the biophysical underpinnings of ictal HFOs.MethodsHere we examine ictal HFOs from multi-scale electrophysiological recordings during spontaneous human rhythmic onset seizures. We compare features of ictal discharges in both the seizure core and penumbra, as defined by multiunit activity patterns.ResultsWe show marked differences in spectral features, unit coupling, and information theoretic characteristics of HFOs during ictal discharges before and after local seizure invasion. Furthermore, we tie these timing-related differences to different spatial domains of seizures, showing that eccentric, penumbral discharges are widely distributed and less useful for seizure localization, which may explain the variable utility of HFOs in seizure localization and forecasting.InterpretationWe thus identify two distinct classes of ictal HFOs, implying two different mechanisms underlying pathological HFOs with contrasting significance for seizure localization.


2017 ◽  
Vol 9 (1) ◽  
pp. 175-180
Author(s):  
Liisa Kraama ◽  
Pablo Yague ◽  
Heikki Kyröläinen ◽  
Seppo Pulkkinen ◽  
Tuuli Matinsalo ◽  
...  

Summary Study aim: Physically active adults have been shown to have higher heart rate variability (HRV) than less active adults, but less is known about children in this regard. In adults, training-induced changes in physical performance have been shown to be related to increase in HRV, especially in its high frequency component (HF), which is a marker of parasympathetic activity. The purpose of this study was to examine whether 8 weeks of instructed physical training would improve physical performance and cardiac autonomic function (HRV) in secondary school pupils and to examine the relationship between changes in physical performance and the function of the autonomic nervous system. Material and methods: The test group included 12 girls and 12 boys and the control group 7 girls and 7 boys. All the sub­jects were 13-15 years old. Physical training included warm up, circuit training, endurance training, stretching and relaxation 3 times a week for eight weeks. Endurance training intensity was 70-75% of maximal heart rate. Endurance, flexibility, speed and power were measured before and after training. The low frequency (LF) and high frequency (HF) components of HRV were recorded in supine rest and in standing conditions before and after the eight-week period. Results: Time to exhaustion in the endurance test increased in the test group (p < 0.001), flexibility and ball throwing improved in the test group (p < 0.05), while no changes were observed in the control group. No significant changes were observed in HRV in either group. Conclusions: In conclusion, eight weeks of physical training improves physical performance in children, but it might not affect autonomic cardiac function.


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