A comprehensive review of heart rate variability as an indicator in the regulation of the autonomic nervous system by acupuncture:a bibliometric analysis

This study sought to conduct a bibliometric analysis of acupuncture studies focusing on heart rate variability(HRV)and to investigate the correlation between various acupoints and their effects on HRV by utilizing association rule mining and network analysis.A total of 536 publications on the topic of acupuncture studies based on HRV.The disease keyword analysis revealed that HRV-related acupuncture studies were mainly related to pain,inflammation,emotional disorders,gastrointestinal function,and hypertension.A separate analysis was conducted on acupuncture prescriptions,and Neiguan(PC6)and Zusanli(ST36)were the most frequently used acupoints.The core acupoints for HRV regulation were identified as PC6,ST36,Shenmen(HT7),Hegu(LI4),Sanyinjiao(SP6),Jianshi(PC5),Taichong(LR3),Quchi(LI11),Guanyuan(CV4),Baihui(GV20),and Taixi(KI3).Additionally,the research encompassed 46 reports on acupuncture animal experiments conducted on HRV,with ST36 being the most frequently utilized acupoint.The research presented in this study offers valuable insights into the global research trend and hotspots in acupuncture-based HRV studies,as well as identifying frequently used combinations of acupoints.The findings may be helpful for further research in this field and provide valuable information about the potential use of acupuncture for improving HRV in both humans and animals.

Heart Rate Variability as an Indicator of Stress in Students’ Athletes

Introduction: The wellbeing of student’s athletes has a paramount importance, a prolonged period of cognitive and physical performance that characterizes the life of student’s athletes often leads to fatigue, and a psychobiological state that increases the risk of injury and accidents. The use of Heart rate variability (HRV) has become increasingly popular as a non-invasive methodology that provides an indirect insight into the autonomic nervous system. HRV can be utilized as a diagnostic tool in detection of autonomic nervous system impairment and sympatho-vagal imbalance. HRV technology is employed to monitor the internal response of athletes to workload and identify athletes’s psychophysical stress to predict and therefore prevent injuries. Objective: The objective of the investigation is to establish whether the use of Polar H10 sensor heart rate monitors worn by athletes in a sitting position (inclination 60 degrees) during periods characterized by stress can provide a valid and non-invasive method to assess the psychophysiological state during sports competition and school exams. Method and Statistics: In the study, the HRV of 12 basketball students athletes and 4 students non-athletes was analyzed as a control group. The autonomic nervous system activity was assessed based on heart variability parameters (HRV): SDNN, rMSSD, LF, HF, and LF/HF. The measurements were made after establishing the baseline at rest, during the training phase (CT), competition phase (CC) and during the acute phase of stressors due to school exams coinciding with the competitive season (CC + E). Results: Compared to the respective values prior to the stress of the competitions and exams, a significant decrease in HRV indices was found: SDNN (P Conclusions: The analysis and examination of the data on the sample of the student population also showed a statistically significant correlation between decreased cardiac variability and injuries or indisposition to physical exertion.

Synchronous measurements of prefrontal activity and pulse rate variability during online video game playing with functional near-infrared spectroscopy

Interactions between the central nervous system(CNS)and autonomic nervous system(ANS)play a crucial role in modulating perception,cognition,and emotion production.Previous studies on CNS–ANS interactions,or heart–brain coupling,have often used heart rate variability(HRV)metrics derived from electrocardiography(ECG)recordings as empirical measurements of sympathetic and parasympathetic activities.Functional near-infrared spectroscopy(fNIRS)is a functional brain imaging modality that is increasingly used in brain and cognition studies.The fNIRS signals contain frequency bands representing both neural activity oscillations and heartbeat rhythms.Therefore,fNIRS data acquired in neuroimaging studies can potentially provide a single-modality approach to measure task-induced responses in the brain and ANS synchronously,allowing analysis of CNS–ANS interactions.In this proof-of-concept study,fNIRS was used to record hemodynamic changes from the foreheads of 20 university students as they each played a round of multiplayer online battle arena(MOBA)game.From the fNIRS recordings,neural and heartbeat frequency bands were extracted to assess prefrontal activities and shortterm pulse rate variability(PRV),an approximation for short-term HRV,respectively.Under the experimental conditions used,fNIRS-derived PRV metrics showed good correlations with ECG-derived HRV golden standards,in terms of absolute measurements and video game playing(VGP)-related changes.It was also observed that,similar to previous studies on physical activity and exercise,the PRV metrics closely related to parasympathetic activities recovered slower than the PRV indicators of sympathetic activities after VGP.It is concluded that it is feasible to use fNIRS to monitor concurrent brain and ANS activations during online VGP,facilitating the understanding of VGP-related heart–brain coupling.

Effects of Moxa (Artemisia Vulgaris) Smoke Inhalation on Heart Rate and Its Variability

Objective: To evaluate the changes of human heart rate (HR) and heart rate variability (HRV) during and after moxa smoke inhalation and to investigate the effects of moxa smoke on human autonomic nervous system. Methods: 24 healthy volunteers were exposed to moxa smoke with their HRV parameters measured before, during and after the moxa smoke inhalation. Results: The healthy volunteers exposed to moxa smoke had significant reductions in HR and also significant changes in HRV parameters. Conclusions: Moxa smoke can improve the autonomic nervous system activity. The inhalation of moxa smoke will induce a depressant effect on human body.

Heart Rate Variability, Standard of Measurement, Physiological Interpretation and Clinical Use in Mountain Marathon Runners during Sleep and after Acclimatization at 3480 m

Fluctuations in autonomic cardiovascular regulation during exposure to high altitude may increase the risk of heart attack during waking and sleep. This study compared heart rate variability (HVR) and its components during sleep at low altitude and after 30 - 41 hours of acclimatization at high altitude (3480 m) in five mountain marathon runners controlled for diet, drugs, light-dark cycle and jet lag. In comparison to sea level, RR-intervals during sleep at high altitude decreased significantly (P 0.001). The significant increase in sympathetic autonomic cardiovascular modulation at high altitude protects against excessive oxygen deprivation during sleep. Increases in R-R intervals can require longer periods of acclimatization at3480 m to mitigate the effects of altitude/hypoxia on sympathetic tone, thus reducing cardiovascular distress at rest during waking and sleep and probably before during and after athletic performance at altitude.

Evaluation of autonomic nervous system by heart rate variability and differential count of leukocytes in athletes

Top Japanese sprinters were evaluated for their physical condition, autonomic function, blood chemistry, differential leukocyte count and blood lactate level before and after short, maximal exercise to explore methods of quantifying their conditioning level. Statistical analysis of data obtained before and 10 min after exercise were used to estimate the athletes’ autonomic capacity during recovery. Pre and post exercise variances in differential leukocyte count revealed strong correlations between neutrophil and sympathetic activity, and lymphocyte and parasympathetic activity. The results of the study demonstrated significant alterations in autonomic parameters and differential white blood cell count in response to maximal exercise.

Normal values of heart rate variability at rest in a young, healthy and active Mexican population

This study analyzed Heart Rate Variability in a large sample of active young subjects within a narrow age range (18 to 25), using time and frequency domain methods and a Poincaré plot. Heart rate was recorded (beat to beat) for 30 minutes at rest in 200 healthy subjects divided into 4 groups: 50 sportsmen (20.54 ± 1.52 years);50 active men (21.22 ± 1.31 years);50 sportswomen (20.10 ± 1.87 years) and 50 active women (20.92 ± 1.87 years). Significant differences were found for most parameters between athletes and active subjects (male and female) but not between genders. Percentile distributions were provided for all parameters (according to gender and physical activity level) to be used as references in future researches.

Effects of Impaired Glucose Metabolism on Heart Rate Variability and Blood Pessure Variability in Essential Hpertensive Patients

To investigate the effects of impaired glucose metabolism (IGM) on cardiovascular autonomic nervous systems in essential hypertensive (EH) patients by comparing heart rate variabil-ity (HRV) and blood pressure variability (BPV) in EH patients with or without type 2 diabetes melli-tus (T2DM). Simultaneous 24-h recordings of ambulatory ECG and blood pressure monitoring were performed in 36 male old patients with simple EH and 33 male old patients with EH combined with T2DM. HRV analysis included time domain parameters such as SDNN, SDANN, SDNNi, rMSSD and pNN50, and total spectral power (TP) of HRV, which mainly consists of VLF, LF and HF com-ponent along with LF/HF ratio, was also obtained. The value of ambulatory blood pressure was rep-resented as the mean blood pressure (mean systolic/mSBP, diastolic/mDBP and pulse pressure/mPP) during different periods (24 h/24 h, day time/d and night time/n). Standard deviation (SD) as well as coefficient of variance (CV) of blood pressure during each above-mentioned period were obtained to reflect the long-term BPV. Our result showed that SDNN, SDNNi, SDANN, rMSSD, PNN50, TP and HF of HRV in cases of EH with T2DM were all significantly lower than those in simple EH subjects (P<0.05). No significant differences in VLF or LF was found between the two groups (P>0.05), while LF/HF ratio was significantly higher in EH with T2DM patients than in simple EH subjects (P<0.01). Moreover, dmSBP, 24 h-mPP and dmPP were all significantly higher in EH with T2DM patients than in simple EH subjects (P<0.05), while nmSBP, 24 h-mSBP, 24 h-mDBP, dmDBP, nmDBP or nmPP showed no significant difference between this two groups of patients (P>0.05). And dSBPSD, dSBPCV and 24 h-SBPSD were all significantly higher in EH with T2DM patients than in simple EH subjects (P<0.05), while the other BPV indexes showed no significant difference between this two groups (P>0.05). It is concluded that the cardiovascular autonomic nervous systems in EH patients was further impaired by T2DM, displaying lowering of HRV and enlargement of BPV, which in turn induced abnormal structural and functional changes of cardiovascular systems. Therefore, improving cardiovascular autonomic nervous systems might reduce the occurrence of cardiovascular complica-tions in the EH patients with IGM.

Relationship between Ambient Fine Particles and Ventricular Repolarization Changes and Heart Rate Variability of Elderly People with Heart Disease in Beijing, China

Objective To explore the effects of particulate matters less than 2.5 μm in aerodynamic diameter (PM 2.5) on heart repolarization/depolarization and heart rate variability (HRV). Methods We conducted a panel study for elderly subjects with heart disease in Beijing from 2007 to 2008. PM 2.5 was measured at a fixed station for 20 h continuously each day while electrocardiogram (ECG) indexes of 42 subjects were also recorded repeatedly. Meteorological data was obtained from the China Meteorological Data Sharing Service System. A mixed linear regression model was used to estimate the associations between PM 2.5 and the ECG indexes. The model was adjusted for age, body mass index, sex, day of the week andmeteorology. Results Significant adverse effects of PM 2.5 on ECG indexes reflecting HRV were observed statistically and the strongest effect of PM 2.5 on HRV was on lag 1 day in our study. However, there were no associations between PM 2.5 and ECG indexes reflecting heart repolarization/depolarization. Additionally, the effects of PM 2.5 on subjects with hypertension were larger than on the subjects without hypertension. Conclusion This study showed ambient PM 2.5 could affect cardiac autonomic function of the elderly people with heart disease, and subjects with hypertension appeared to be more susceptive to the autonomic dysfunction induced by PM 2.5.

Gene polymorphisms associated with sudden decreases in heart rate during extensive peritoneal lavage with distilled water after gastrectomy

BACKGROUND Our previous study found that the telomerase-associated protein 1(TEP1,rs938886 and rs1713449)and homo sapiens RecQ like helicase 5(RECQL5,rs820196)single nucleotide polymorphisms(SNPs)were associated with changes in heart rate(HR)≥30%during peritoneal lavage with distilled water after gastrectomy.This study established a single tube method for detecting these three SNPs using two-dimensional(2D)polymerase chain reaction(PCR),and investigated whether SNP-SNP and SNP-environment interactions increase the risk of high HR variability(HRV).AIM To investigate whether genotypes,genetic patterns,SNP-SNP and SNP-environment interactions were associated with HRV.METHODS 2D PCR was used to establish a single-tube method to detect TEP1 rs938886 and rs1713449 and RECQL5 rs820196,and the results were compared with those of sanger sequencing.After adjusting for confounders such as age,sex,smoking,hypertension,and thyroid dysfunction,a nonconditional logistic regression model was used to assess the associations between the genotypes and the genetic patterns(codominant,dominant,overdominant,recessive,and additive)of the three SNPs and a risk≥15%or≥30%of a sudden drop in HR during postoperative peritoneal lavage in patients with gastric cancer.Gene-gene and geneenvironment interactions were analyzed using generalized multifactor dimensionality reduction.RESULTS The coincidence rate between the 2D PCR and sequencing was 100%.When the HRV cutoff value was 15%,the patients with the RECQL5(rs820196)TC genotype had a higher risk of high HRV than those who had the TT genotype(odds ratio=1.97;95%CI:1.05-3.70;P=0.045).Under the codominant and overdominant models,the TC genotype of RECQL5(rs820196)was associated with a higher risk of HR decrease relative to the TT and TT+CC genotypes(P=0.031 and 0.016,respectively).When the HRV cutoff value was 30%,patients carrying the GC-TC genotypes of rs938886 and rs820196 showed a higher HRV risk when compared with the GG–TT genotype carriers(P=0.01).In the three-factor model of rs938886,rs820196,and rs1713449,patients carrying the GC-TC-CT genotype had a higher risk of HRV compared with the wild-type GG-TT-CC carriers(P=0.01).For rs820196,nonsmokers with the TC genotype had a higher HRV risk compared with nonsmokers carrying the TT genotype(P=0.04).When the HRV cutoff value was 15%,patients carrying the TT-TT and the TC-CT genotypes of rs820196 and rs1713449 showed a higher HRV risk when compared with TT-CC genotype carriers(P=0.04 and 0.01,respectively).Patients carrying the GC-CT-TC genotypes of rs938886,rs1713449,and rs820196 showed a higher HRV risk compared with GG-CC-TT genotype carriers(P=0.02).When the HRV cutoff value was 15%,the best-fitting models for the interactions between the SNPs and the environment were the rs820196-smoking(P=0.022)and rs820196-hypertension(P=0.043)models.Consistent with the results of the previous grouping,for rs820196,the TC genotype nonsmokers had a higher HRV risk compared with nonsmokers carrying the TT genotype(P=0.01).CONCLUSION The polymorphism of the RECQL5 and TEP1 genes were associated with HRV during peritoneal lavage with distilled water after gastrectomy.

Heart rate variability： a new tool to predict complications in adult cardiac surgery

心率可变性(HRV ) 指在连续心跳之间的变化，它取决于自治神经系统的同情、副交感的分支的连续调整。HRV 被显示了作为在心肌的梗塞和糖尿病的神经病的早警告症状以后的风险的一个预言者有效，并且在心病学，背景是认出是为在医院承认以后并且在分泌物以后的风险层化的一个有用工具的现在。最近的证据建议 HRV 分析可能甚至在经历心脏的外科，和现在的评论的病人预言复杂并发症在当前的临床的实践为 HRV 使用在成年心脏的外科和观点总结 HRV 分析的重要性。尽管未来在 HRV 能在成年心脏的外科被包括进每日的临床的实践以前，更大的研究被保证， HRV 是可能在早手术后的阶段并且在医院停留期间检测自治不稳定性的一个新奇工具，因此预言或迅速诊断许多手术后的复杂并发症。

Analysis of heart rate variability based on singular value decomposition entropy

估计心率变化的动力学能关于心地位提供珍贵信息。在这研究，用单个价值分解熵(SvdEn ) 的概念的心失败病人和健康的人的心率可变性(HRV ) 的整齐被分析。SvdEn 用规范的单个价值从时间数列，时间序列被计算。这个方法的优点是它的简洁和快计算。它启用很短、非静止的数据集的分析。结果证明有充血的心失败(CHF ) 的病人的 SvdEn 显示出低价值(SvdEn：0.056 ± 0.006， p 【 0.01 ) 它能完全与健康题目被分开。另外，在白天和晚上之间的 SvdEn 价值的差别被作出对有利的裁决健康的组。SvdEn 与年龄减少。越多降低 SvdEn 价值，越 higher 心疾病的风险。而且， SvdEn 与心节奏的精力被联系。结果证明为为临床的应用处于不同生理的状态区别 HRV 的那使用的 SvdEn 可行、简单。

Changes in Heart Rate Variability and Effects on POMS by Whether or Not Soil Observation Was Performed

Introduction: The effects of performing soil observation on autonomic nerve function (ANS) and the profile of mood states (POMS) particularly for upsurge of sentiment were studied table. Methods: The subjects were divided into two groups: Group A with soil observation, and Group B without it. Soil observation was performed by smelling soil, touching the soil and other ways. Evaluation was made using heart rate change variability, POMS and visual analog scale (VAS). Results: Group A showed an increase in high frequency (HF) and the LF (low frequency)/HF ratio and a decrease in heart rate, leading to activating the functions of the parasympathetic nervous system. VAS values for “not comforted at all” indicated that the scale was lower in Group A than in Group B. In POMS, a factor of “vigor” became lower in Group B than in Group A. Discussion: It was suggested that soil observation was effective in bringing people to a state of physiological and mental relaxation and reducing stress because it raised the degree of being comforted, increased HF, decreased the heart rate and activated the parasympathetic nervous system. Conclusions: By performing soil observation, the heart rate decreased, HF increased and an upsurge sentiment became normalized.

Power Spectral Analysis of Heart Rate Variability of Driver Fatigue

This investigation was to evaluate the driving fatigue based on power spectral analysis of heart rate variability (HRV) under vertical vibration. Forty healthy male subjects (29.7±3.5 years) were randomly divided into two groups, Group A (28.8±4.3 years) and Group B (30.6±2.7 years). Group A (experiment group) was required to perform the simulated driving and Group B (control group) kept calm for 90 min. The frequency domain indices of HRV such as low frequency (0.04 0.15 Hz, LF), high frequency (0.150.4 Hz, HF), LF/HF together with the indices of hemodynamics such as blood pressure (BP) and heart rate (HR) of the subjects between both groups were calculated and analyzed after the simulated driving. There were significances of the former indices between both groups (P<0.05). All the data collected after experiment of Group A was observed the remarkable linear correlation (P<0.05) and parameters and errors of their linear regression equation were stated (α=0.05, P<0.001) in this paper, respectively. The present study investigated that sympathetic activity of the subjects enhanced after the simulated driving while parasympathetic activities decreased. The sympathovagal balance was also improved. As autonomic function indictors of HRV reflected fatigue level, quantitative evaluation of driving mental fatigue from physiological reaction could be possible.

Does heart rate variability correlate with long-term prognosis in myocardial infarction patients treated by early revascularization?

AIM To assess the prevalence of depressed heart rate variability(HRV) after an acute myocardial infarction(MI),and to evaluate its prognostic significance in the present era of immediate reperfusion.METHODS Time-domain HRV(obtained from 24-h Holter recordings) was assessed in 326 patients(63.5 ± 12.1 years old; 80% males),two weeks after a complicated MI treated by early reperfusion: 208 ST-elevation myocardial infarction(STEMI) patients(in which reperfusion wassuccessfully obtained within 6 h of symptoms in 94% of cases) and 118 non-ST-elevation myocardial infarction(NSTEMI) patients(percutaneous coronary intervention was performed within 24 h and successful in 73% of cases). Follow-up of the patients was performed via telephone interviews a median of 25 mo after the index event(95%CI of the mean 23.3-28.0). Primary endpoint was occurrence of all-cause or cardiac death; secondary end-point was occurrence of major clinical events(MCE,defined as mortality or readmission for new MI,new revascularization,episodes of heart failure or stroke). Possible correlations between HRV parameters(mainly the standard deviation of all normal RR intervals,SDNN),clinical features(age,sex,type of MI,history of diabetes,left ventricle ejection fraction),angiographic characteristics(number of coronary arteries with critical stenoses,success and completeness of revascularization) and long-term outcomes were analysed.RESULTS Markedly depressed HRV parameters were present in a relatively small percentage of patients: SDNN < 70 ms was found in 16% and SDNN < 50 ms in 4% of cases. No significant differences were present between STEMI and NSTEMI cases as regards to their distribution among quartiles of SDNN(χ~2 =1.536,P = 0.674). Female sex and history of diabetes maintained a significant correlation with lower values of SDNN at multivariate Cox regression analysis(respectively: P = 0.008 and P = 0.008),while no correlation was found between depressed SDNN and history of previous MI(P = 0.999) or number of diseased coronary arteries(P = 0.428) or unsuccessful percutaneous coronary intervention(PCI)(P = 0.691). Patients with left ventricle ejection fraction(LVEF) < 40% presented more often SDNN values in the lowest quartile(P < 0.001). After > 2 years from infarction,a total of 10 patients(3.1%) were lost to follow-up. Overall incidence of MCE at follow-up was similar between STEMI and NSTEMI(P = 0.141),although all-cause and cardiac mortality were higher among NSTEMI cases(respectively: 14% vs 2%,P = 0.001; and 10% vs 1.5%,P = 0.001). The Kaplan-Meier survival curves for all-cause mortality and for cardiac deaths did not reveal significant differences between patients with SDNN in the lowest quartile and other quartiles of SDNN(respectively: P = 0.137 and P = 0.527). Also the MCE-free survival curves were similar between the group of patients with SDNN in the lowest quartile vs the patients of the other SDNN quartiles(P = 0.540),with no difference for STEMI(P = 0.180) or NSTEMI patients(P = 0.541). By the contrary,eventsfree survival was worse if patients presented with LVEF < 40%(P = 0.001).CONCLUSION In our group of patients with a recent complicated MI,abnormal autonomic parameters have been found with a prevalence that was similar for STEMI and NSTEMI cases,and substantially unchanged in comparison to what reported in the pre-primary-PCI era. Long-term outcomes did not correlate with level of depression ofHRV parameters recorded in the subacute phase of the disease,both in STEMI and in NSTEMI patients. These results support lack of prognostic significance of traditional HRV parameters when immediate coronary reperfusion is utilised.

Qi Gong and Heart Rate Variability: A Systematic Review

Qì Gōng is a type of exercise that involves meditation and is used for health. With a background from the martial arts, it is known also as an auto healing exercise with three main elements according to Traditional Chinese Medicine (TCM): body focus (posture and movement), breathing and mind focus (meditative elements). Heart rate variability is a tool that allows us to measure the autonomic system velocity to detect and respond to unexpected stimuli. So our goal was to build a systematic review of Qi Gong and Heart rate variability. PUBMED, EBSCO and Science Direct data bases were searched. Key terms (MeSH) were Heart Rate Variability and Ch’i Kung OR Qi Gong with a 10-year filter. Four independent reviewers analyzed all articles and excluded duplicated articles, articles in Chinese and articles with no adherence to the subject. The end result was 5 studies selected. Our results showed no significant improvements in HRV with the practice of Qì Gōng, probably because of data heterogeneity. We found 5 types of Qì Gōng, 3 different instruments and different time intervals to measure HRV and 2 different age groups in the studies. We can conclude that there is evidence that Qì Gōng can improve HRV but studies that would use the same parameters are needed to further confirm that.

Using of spectral analysis of heart rate variability for increasing reliability of bicycle ergometry results

The aim was to study the suitability of the heart rate variability (HRV) spectral parameters for evaluations of bicycle ergometry results in coronary heart disease (CHD) patients. Methods. Our study included 243 male CHD patients aged 49±8 years. The coronary atherosclerosis was assessed by coronary angiography. The results of bicycle ergometry, Doppler echocardio-graphy and HRV spectral analysis were also analyzed. The duration of each stage of bicycle ergometry was 3 min, the initial load value was 25 W. Dynamic load continued until the patient had reached 75% of heart rate from his maximal age level. The maximal level of load achieved (i.e. load tolerance) was taken into consideration. We calculated sensitivity (Se), specificity (Sp), likelihood ratios of positive (LR+) and negative (LR-) bicycle ergometry results. Results. All patients had similar clinical characteristics. LR+ become maximal under the moderate load tolerance. LR- are maximal in the CHD patients with high load tolerance. Thus, the excessiveness of false-negative results of bicycle ergometry is in CHD patients with high load tolerance. Reliability of results of bicycle ergometry increased under using assessments of low-frequency (LF) range power of HRV spectrum. Conclusions. Thus,the using of LF range power of HRV spectrum increases reliability of bicycle ergometry (or other load tests) results in CHD patients.

A Study into Blood Flow, Heart Rate Variability, and Body Surface Temperature While Listening to Music

In this study we examined the relaxing effects of listening to music on a total of 12 women aged from their 20s to their 40s by measuring their blood flow, heart rate variability, and their body surface temperature. As a result, We found that there was a tendency for the volume of blood flow to the fingertips to significantly increase when listening to classical music, but there was a variety of changes in blood flow between each age group for healing music and J-Pop music. When measuring heart rate it was found that the LF/HF value, which is an index for the autonomic nervous system which shows tension and stress, fell significantly when listening to each type of music. Lastly, there was a trend for body surface temperature to rise when listening to classical or healing music, a rise which was particularly significant when listening to healing music. This study shows that a relaxing effect can be expected for all indices when listening to classical music. However, for healing music and J-Pop, personal musical preferences seemed to have an effect and the results were varied.

Modeling of Heart Rate Variability Using Time-Frequency Representations

The heart rate variability signal is highly correlated with the respiration even at high workload exercise.It is also known that this phenomenon still exists during increasing exercise.In the current study,we managed to model this correlation during increasing exercise using the time varying integral pulse frequency modulation(TVIPFM)model that relates the mechanical modulation(MM)to the respiration and the cardiac rhythm.This modulation of the autonomic nervous system(ANS)is able to simultaneously decrease sympathetic and increase parasympathetic activity.The TVIPFM model takes into consideration the effect of the increasing exercise test,where the effect of a time-varying threshold on the heart period is studied.Our motivation is to analyze the heart rate variability(HRV)acquired by time varying integral pulse frequency modulation using time frequency representations.The estimated autonomic nervous system(ANS)modulating signal is filtered throughout the respiration using a time varying filtering,during exercise stress testing.And after summing power of the filtered signal,we compare the power of the filtered modulation of the ANS obtained with different time frequency representations:smoothed pseudo Wigner–Ville representation,spectrogram and their reassignments.After that,we used a student t-test p<0.01 to compare the power of heart rate variability in the frequency band of respiration and elsewhere.

Protective effects of rice bran hydrolysates on heart rate variability,cardiac oxidative stress,and cardiac remodeling in high fat and high fructose diet-fed rats

Objective:To examine the ameliorative effect of rice bran hydrolysates(RBH)on metabolic disorders,cardiac oxidative stress,heart rate variability(HRV),and cardiac structural changes in high fat and high fructose(HFHF)-fed rats.Methods:Male Sprague-Dawley rats were daily fed either standard chow diet with tap water or an HFHF diet with 10%fructose in drinking water over 16 weeks.RBH(500 and 1000 mg/kg/day)was orally administered to the HFHF-diet-fed rats during the last 6 weeks of the study period.At the end of the treatment,metabolic parameters,oxidative stress,HRV,and cardiac structural changes were examined.Results:RBH administration significantly ameliorated metabolic disorders by improving lipid profiles,insulin sensitivity,and hemodynamic parameters.Moreover,RBH restored HRV,as evidenced by decreasing the ratio of low-frequency to highfrequency power of HRV,a marker of autonomic imbalance.Cardiac oxidative stress was also mitigated after RBH supplementation by decreasing cardiac malondialdehyde and protein carbonyl,upregulating eNOS expression,and increasing catalase activity in the heart.Furthermore,RBH mitigated cardiac structural changes by reducing cardiac hypertrophy and myocardial fibrosis in HFHFdiet-fed rats.Conclusions:The present findings suggest that consumption of RBH may exert cardioprotective effects against autonomic imbalances,cardiac oxidative stress,and structural changes in metabolic syndrome.