scholarly journals Study on the Relationship Between Orthostatic Hypotension and Heart Rate Variability, Pulse Wave Velocity Index, and Frailty Index in the Elderly: A Retrospective Observational Study

2020 ◽  
Vol 7 ◽  
Author(s):  
Lun Li ◽  
Huanhuan Li ◽  
Li He ◽  
Hongyan Chen ◽  
Yunqiao Li
Keyword(s):  
Heart Rate ◽  
High Frequency ◽  
Cardiac Cycle ◽  
Pulse Wave ◽  
Frailty Index ◽  
Low Frequency ◽  
The Elderly ◽  
Autonomic Nerve ◽  
Autonomic Nerve Function ◽  
The Relationship

Background: Orthostatic hypotension (OH) is a common disease of the elderly. It is generally believed that the pathogenesis of OH is related to the impairment of autonomic nerve function and the decreased vascular capacity regulation. This study aims to explore the relationship between OH and heart rate variability (HRV) parameters, which reflects autonomic nerve function; ankle-brachial pressure index (ABI), which reflects the degree of vascular stenosis; pulse wave velocity (PWV) index, which reflects vascular stiffness; and frailty index (FI), which reflects the overall health status of the elderly.Methods: From January to September 2018, 24-h HOLTER monitoring, PWV, and ABI were performed in 108 elderly patients with OH and 64 elderly patients who underwent physical examination in our hospital. Analysis software was used to record the subject's standard deviation of the cardiac cycle (SDNN), the standard deviation of the 5-min average cardiac cycle (SDANN), the square root of the average square sum of consecutive n-interval differences (rMSSD), the percentage of the number of adjacent cardiac interval differences >50 ms (pNN50), low frequency (LF), high frequency (HF), very low frequency (VLF), and low frequency/high frequency ratio (LF/HF). Then, FI was evaluated qualitatively and quantitatively in the form of a scale.Results: There was no statistical difference between the two groups on the basis of age, sex, body mass index (BMI), low-density lipoprotein (LDL), resting heart rate, blood pressure, fasting blood glucose, long-term medication, etc. There were significant differences in PWV, SDNN, LF, VLF, and LF/HF between the two groups (P < 0.05). The risk factor of OH in the qualitative (P = 0.04) and quantitative (P = 0.007) index FI was higher in the OH group than in the control group. The risk factors of OH were PWV, SDNN, VLF, LF/HF, and FI, where FI was positively correlated and LF/HF was negatively correlated.Conclusions: The pathogenesis of OH is related to vascular stiffness, imbalance of autonomic nerve regulation, and its comprehensive health status in the elderly. However, arteriosclerosis has not been confirmed as an independent risk factor.Clinical Trial Registration: Retrospectively registered, http://www.chictr.org.cn.

Effect of Auricular Acupuncture on Gastrointestinal Motility and Its Relationship with Vagal Activity

2013 ◽  
Vol 31 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Han Li ◽  
Yin-Ping Wang
Keyword(s):  
Vagus Nerve ◽  
High Frequency ◽  
Low Frequency ◽  
Autonomic Nerve ◽  
Auricular Acupuncture ◽  
Vagal Activity ◽  
Nerve Function ◽  
Gi Transit ◽  
The Relationship ◽  
Gi Motility

Background Vagus nerve stimulation is capable of regulating autonomic nerve function. In Traditional Chinese Medicine, the effect of auricular acupuncture (AA) is mediated by the vagus. This study was designed to investigate the effect of AA on gastrointestinal (GI) motility and the relationship of this effect with the vagus nerve. Methods 50 rats were divided into five groups for observation of the effects of different types of acupuncture and influencing factors: control, AA, somatic acupuncture (SA), atropine and atropine+AA. The acupuncture points used for AA were ST (Stomach) and SI (Small intestine), while the acupuncture point used for SA was ST36. Electroacupuncture was performed for 15 min. A model of reduced GI motility was established using ethanol, and GI transit rate was used to measure GI motility. Heart rate variability (HRV) and the effect of atropine administration were investigated to study the relationship between AA and vagal activity. Results The GI transit rate increased in both the AA and SA groups compared with control, and no significant difference was found between their effects. In addition, after atropine administration, AA was found to be ineffective in influencing the GI transit rate. In the HRV analysis, no significant differences were found in the absolute low frequency normalised units, high frequency normalised units or the low frequency/high frequency component ratio in the AA or SA groups compared with control. After administration of atropine AA still had no effect on HRV. Conclusions The function of AA in improving GI motility is similar to that of SA, and this effect can be blocked by the presence of atropine, indicating that this effect is regulated by the vagus. However, HRV did not reflect the acupuncture-induced changes in vagal nerve function.

scholarly journals Effect of moderate physical exercises on the relationship of variability of the heart rhythm with the level of blood pressure and hemodynamic functions in women with essential hypertension

2020 ◽  
pp. 64-73
Author(s):  
Б.И. Кузник ◽  
Ю.Н. Смоляков ◽  
Е.С. Гусева ◽  
С.О. Давыдов ◽  
И.В. Файн
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Heart Rate Variability ◽  
Essential Hypertension ◽  
High Frequency ◽  
Low Frequency ◽  
Mean Square ◽  
Positive Correlations ◽  
The Relationship

Цель исследования - выявление взаимосвязи между показателями вариабельности сердечного ритма (ВСР), кровяным давлением и гемодинамическими функциями у женщин, страдающих гипертонической болезнью (ГБ) и находящихся на медикаментозной терапии (ГБ-1), либо в дополнение к этому, проходящих регулярные курсы кинезитерапии (ГБ-2). Методика. Наблюдения проведены на 72 женщинах, страдающих артериальной гипертензией II стадии. В группу ГБ-1 вошли 37 женщин с ГБ, находящихся на медикаментозной терапии, в группу ГБ-2 - 35 женщин с ГБ, которые, помимо медикаментозной терапии, регулярно проходили на протяжении 2-3 лет по 3-4 полуторамесячных курса кинезитерапии (управляемые умеренные физические нагрузки). Для изучения гемодинамики был использован датчик динамического рассеяния света (miniature Dynamic Light Scattering - mDLS) от Elfi-Tech (Rehovot, Israel), измеряющий сигналы, инициированные кожным кровотоком, и использующий методику разложения сигнала на частотные компоненты, связанные с разными гемодинамическими источниками. Из пульсовой компоненты mDLS сигнала извлекалась информация о вариабельности RR-интервалов и рассчитывались индикаторы вариабельности сердечного ритма. Введен показатель «гемодинамический индекс» (Hemodynamic Index - HI). Зависимость HI от скорости сдвига интерпретируется путем сопоставления каждой полосе частот определенной скорости сдвига (HI1 - низкочастотный, HI2 - промежуточный, HI3 - высокочастотный). Использованы следующие относительные (RHI, Relative Hemodynamic Index) и осцилляторные (OHI, Oscillatory Hemodynamic Indexes) гемодинамические индексы: нейрологический (NEUR), Майера (MAYER), дыхательный (RESP) и пульсовой (PULSE). ВСР показатели включали: HR (Heart Rate), PWR (Power) - общую мощность колебаний, LF (Low Frequency), HF (High Frequency), SDNN (Standard Deviation of the Normal-to-Normal), RMSSD (Root Mean Square of the Successive Differences), а также индексы: CVI (Cardiac Vagal Index) и CSI (Cardiac Sympathetic Index). Результаты. У женщин, находящихся исключительно на медикаментозной терапии (ГБ-1), выявляются отрицательные взаимосвязи LF и LF/HF с систолическим, средним и пульсовым давлением. При ГБ-2 проявляются отрицательные связи PWR, LF, HF с пульсовым давлением. При ГБ-1 обнаружены положительные взаимосвязи между HR и гемодинамическими индексами HI1, RHI2 и отрицательная взаимосвязь с RHI3, а также между RMSSD и RHI3 и между HF и HI1/HI3. У пациенток ГБ-2 обнаружена отрицательная корреляция SDNN и RHI1, а также PWR и RHI1; положительные взаимосвязи между PWR и HI2, HI3, RHI2, HF и RHI3 и LF/HF с HI1/HI3; отрицательные связи HF c HI1/HI3 и с RHI1, а также между LF/HF и RHI3, CSI и RHI3. У больных ГБ-1 имеются прямые связи между SDNN, PWR, LF, HF, CVI и NEUR_HI1, что свидетельствует о действии этих факторов на эндотелиальный кровоток (HI1). В группе ГБ-2 установлено наличие лишь положительных связей между LF, HF и NEUR_HI3. У больных ГБ-1 на уровень АД влияют все без исключения осцилляторные ритмы, которые могут оказывать как отрицательное (с MAYER_HI1, PULSE_HI2), так и положительное (MAYER_HI2, RESP_HI3) влияние. У больных ГБ-2 взаимосвязи АД с осцилляторными индексами не обнаружены. Заключение. Уменьшение в группе ГБ-2 по сравнению с больными группы ГБ-1 числа факторов, влияющих на АД и гемодинамику, носит более совершенный и благоприятный характер, что и обеспечивает более быструю и устойчивую нормализацию артериального давления. Aim. To study the relationship between heart rate variability (HRV), blood pressure and hemodynamic functions in women with essential hypertension (EH) receiving a drug therapy alone (EH-1) or in combination with regular courses of kinesitherapy (EH-2). Methods. The study included 72 women with EH. The EH-1 group consisted of 37 women with stage II arterial hypertension. The EH-2 group consisted of 35 women with stage II arterial hypertension who underwent 3-4 1.5-month courses of kinesitherapy (controlled moderate physical activity) on a regular basis for 2-3 years. Hemodynamics was studied with a miniature Dynamic Light Scattering (mDLS) sensor from Elfi-Tech (Rehovot, Israel), which measures signals initiated by the skin blood flow by decomposing the signal into frequency components associated with different hemodynamic sources. Information on the RR interval variability was extracted from the pulse component of mDLS signal, and indicators of heart rate variability were calculated. A Hemodynamic Index (HI) was introduced. The HI dependence on shear rate was interpreted by matching each frequency band with a specific shear rate (HI1, low-frequency; HI2, intermediate; HI3, high-frequency). The following relative (RHI, Relative Hemodynamic Index) and oscillatory (OHI, Oscillatory Hemodynamic Indexes) indexes were used: neurological (NEUR), Mayer (MAYER), respiratory (RESP), and pulse (PULSE) ones. The HRV indexes included HR (Heart Rate), PWR (Power, total oscillation power), LF (Low Frequency), HF (High Frequency), SDNN (Standard Deviation of the Normal-to-Normal), RMSSD (Root Mean Square of the Successive Differences). CVI (Cardiac Vagal Index), and CSI (Cardiac Sympathetic Index). Results. In women who were on drug therapy alone (EH-1), negative relationships were found for LF and LF/HF with systolic, mean and pulse pressure. For EH-2, PWR, LF, and HF negatively correlated with pulse pressure. For EH-1, HR positively correlated with the hemodynamic indices HI1 and RHI2 and negatively correlated with RHI3; RMSSD negatively correlated with RHI3; and HF negatively correlated with HI1/HI3. For patients with EH-2, negative correlations were observed for SDNN and RHI1, PWR and RHI1; positive correlations were found between PWR and HI2; HI3, RHI2, HF and RHI3; and between LF/HF and HI1/HI3. HF negatively correlated with HI1/HI3 and with RHI1. LF/HF negatively correlated with RHI3, and CSI negatively correlated with RHI3. In patients with EH-1, SDNN, PWR, LF, HF, CVI, and NEUR_HI1 were directly related, which indicated an effect of these factors on the endothelial blood flow (HI1). In the EH-2 group, only positive correlations were found between LF, HF, and NEUR_HI3. In EH-1 patients, all oscillatory rhythms influenced BP; this influence could be both negative (for MAYER_HI1, PULSE_HI2) and positive (for MAYER_HI2, RESP_HI3). In EH-2 patients, no relationship was found between blood pressure and oscillatory indices. Conclusion. The smaller number of factors influencing blood pressure and hemodynamics in the EH-2 group compared to the EH-1 group was more beneficial and favorable, which ensured faster and steadier normalization of blood pressure.

A-44 Implications of the Heart Rate Variability Power Spectrum on the Relationship between Prenatal Anxiety Exposure and Child Anxiety in 5-Year-Olds

2021 ◽  
Vol 36 (6) ◽  
pp. 1085-1085
Author(s):  
Christine L Ginalis ◽  
Jeenia Zaki ◽  
Ana Cristina Bedoya ◽  
Yoko Nomura
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Power Spectrum ◽  
High Frequency ◽  
Child Anxiety ◽  
Low Frequency ◽  
Maternal Anxiety ◽  
Prenatal Anxiety ◽  
Anxiety Levels ◽  
The Relationship

Abstract Objective To assess the role of the heart rate variability (HRV) in the relationship between prenatal anxiety exposure and subsequent child anxiety levels. Methods A longitudinal study of mother–child dyads (subsample of 89) measured maternal anxiety during the second trimester of pregnancy (self-reported via STAI-S) and subsequent child anxiety (maternal-reported via BASC-3) and baseline autonomic physiological measures (high and low frequency band of HRV power spectrum) at 5-years-old. Mediation analysis was conducted to test whether child high and/or low frequency HRV mediates the relationship between prenatal anxiety and child anxiety. Results Prenatal anxiety predicted child anxiety (β = 0.137, p = 0.004) and high frequency HRV (β = −0.009, p < 0.001), but not low frequency HRV (β = −0.002, p = 0.231). Mediation analysis using bootstrapping procedure revealed that high frequency HRV (β = 0.044, 95% CI [0.007, 0.085]), but not low frequency HRV (β = 0.0117, 95% CI [−0.007, 0.047]), mediated the relationship between prenatal anxiety and child anxiety. After controlling for high frequency HRV, prenatal anxiety was no longer associated with child anxiety (β = 0.0753, p = 0.148). Conclusion Results indicate that in-utero exposure to maternal anxiety influences the child’s high frequency but not low frequency HRV. Importantly, changes in only high frequency HRV from prenatal anxiety is driving the relationship between prenatal anxiety and child anxiety levels, indicating that maternal anxiety during pregnancy affects the development of the autonomic nervous system with long term effects on child emotional regulation. The results suggest that the high frequency portion of the HRV power spectrum should be assessed in a multidimensional model of fetal programming and subsequent mental health risk of the child.

Abstract P399: The Relationship Between Heart Rate Variability and Common Carotid Artery Intima-media Thickness. The ELSA-Brasil

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Rosangela Hoshi ◽  
Paulo A LOTUFO ◽  
Itamar S Santos ◽  
Alessandra C Goulart ◽  
Jose-Geraldo Mill ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Carotid Artery ◽  
Common Carotid Artery ◽  
High Frequency ◽  
Low Frequency ◽  
Intima Media Thickness ◽  
Media Thickness ◽  
The Mean ◽  
The Relationship

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.

Relationship between Malocclusion and Heart Rate Variability Indices in Young Adults

2011 ◽  
Vol 50 (04) ◽  
pp. 358-363 ◽  
Author(s):  
N. Takeuchi ◽  
M. Furuta ◽  
T. Tomofuji ◽  
M. Morita ◽  
D. Ekuni
Keyword(s):  
Quality Of Life ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Young Adults ◽  
Chronic Stress ◽  
High Frequency ◽  
Low Frequency ◽  
The Relationship ◽  
Oral Impacts

Summary Objectives: Heart rate variability (HRV) has been used to assess sympathetic and parasympathetic modulation of heart rate. Chronic stress relates to reduced HRV. Malocclusion has effects on quality of life, which can lead to chronic stress. Therefore, we hypothesized that malocclusion, as chronic stress, may contribute to reduced HRV. The aim of this study was to investigate the relationship between malocclusion and HRV indices in healthy young adults. Methods: Thirty-seven non-smoking healthy subjects, aged 22 to 25 years, were examined. Malocclusion was defined by Angle classification. HRV indices included root mean square of successive differences, low frequency (LF), high frequency (HF) and ratio of LF to HF. The effects of malocclusion on quality of life and mental health were assessed using self-reported questionnaires, the condition-specific Oral Impacts on Daily Performances index (CS-OIDP) and the Hopkins Symptoms Checklist (HSCL), respectively. Results: Significantly lower score of HF and higher heart rate (HR) level and CS-OIDP score were observed in subjects with malocclusion (n = 17) compared to those in the control subjects (n = 20) (P < 0.05). There was a positive correlation between HR and score of “anxiety” in HSCL (P < 0.05). Conclusions: The data showed an association between malocclusion and lower HRV. Based on our results, orthodontic treatment might contribute not only to improvement of oral esthetic and functional problems but also to improvement of stress and HRV indices.

scholarly journals Low-Frequency Vibration Facilitates Post-Exercise Cardiovascular Autonomic Recovery

2021 ◽  
pp. 431-437
Author(s):  
Kuo-Cheng Liu ◽  
Jong-Shyan Wang ◽  
Chien-Ya Hsu ◽  
Chia-Hao Liu ◽  
Carl PC Chen ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Pulse Wave ◽  
Low Frequency ◽  
Recovery Phase ◽  
High Frequency Power ◽  
Nerve Activity ◽  
Post Exercise ◽  
Frequency Power

It is important to use short breaks to accelerate post-exercise recovery in sports. Previous studies have revealed that vibration can reduce post-exercise muscle soreness. However, there is still high heterogeneity in the effects of vibration on cardiovascular autonomic activities, and most studies to date have focused on high-frequency vibration. This study aimed to investigate the effect of low-frequency lower-body vibration (LBV) on post-exercise changes in heart rate variability and peripheral arterial tone. Ten men and 9 women aged 20 to 25 were recruited for this study. Each subject visited the testing room three times with at least 2 days in between. Each time, the subject received one of the three different vibration frequencies (0, 5, and 15 Hz) in a random order in the sitting position for 10 minutes. LBV was performed immediately after a static standing (control) test and 3-min-step test. Heart rate variability and digital volume pulse wave were recorded during the vibration phase (V1: vibration 0-5 minutes; V2: 6-10 minutes) and the recovery phase (Rc1: recovery phase 11-15 minutes; Rc2: 16-20 minutes). The result of digital pulse wave analysis showed that the reflection index (RI) under 15 Hz decreased during V1. Heart rate of the 15-Hz group also decreased during Rc1 and Rc2. According to the analysis of heart rate variability, low-frequency power/high-frequency power (LF/HF) decreased and normalized high-frequency power (nHF) increased during V2, Rc1 and Rc2 under 15 Hz and, during Rc2 under 5 Hz vibration. This study confirmed that the application of low-frequency LBV after exercise can reduce peripheral vascular tone, accelerate heart rate recovery, decrease cardiac sympathetic nerve activity, and promote parasympathetic nerve activity. The effect was more pronounced at 15 Hz than at 5 Hz. The findings provide a method to accelerate cardiovascular autonomic recovery after exercise.

Effects of 2-Hz and 100-Hz Electroacupuncture Stimulation on Respiratory Function and Heart Rate Variability: A Randomized Crossover Study

2021 ◽  
Author(s):  
Kazufumi Takahashi ◽  
Xiaoming Wang ◽  
Daiyu Shginohara ◽  
Kenji Imai
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Respiratory Function ◽  
Low Frequency ◽  
Frequency Component ◽  
Autonomic Nerve ◽  
High Frequency Component ◽  
Respiratory Function Test ◽  
Function Test

Background: Bronchial contraction and dilation is thought to be caused by non-adrenergic non-cholinergic nerves. Objective: To investigate the effects of low-frequency (1-5 Hz) and high frequency (50-100 Hz) electric acupuncture (EA) stimulation on bronchial dilation. Design: Prospective, single-center study. Setting: Teikyo Heisei University Subjects: Seventeen healthy male adults Randomization: We randomly assigned subjects to 2-Hz EA and 100-Hz EA groups in a crossover trial. The washout period was 2 weeks. Intervention: Both groups underwent a respiratory function test, followed by a 5-minute rest, followed a 5-minute rest or EA stimulation, followed by a 5- min rest. Heart rate variability was measured at rest, followed by another respiratory function test. Acupuncture was delivered near the cervical ganglia at the level of the sixth cervical vertebra on the left side. EA stimuli were set to 2-Hz or 100-Hz, and stimulation intensity was set to a level where no pain was felt. Main outcome measures: Spirometry (forced vital capacity, forced expiratory volume in 1 s, and maximum respiratory flow), autonomic nerve activity (low-frequency component, high-frequency component, and their ratio), and heart rate variability. Results: Heart rate variability analysis showed significant differences in heart rate between the 2-Hz EA and 100-Hz EA groups. The 2-Hz EA group showed a significant increase in HF. Conclusions: 2-Hz EA stimulation resulted in decreased heart rate and increased HF during stimulation. This may be more effective for regulation of the autonomic nerves of the cardiopulmonary system than 100-Hz EA stimulation. Future studies are required to confirm our findings.

scholarly journals Power spectral analysis of heart rate variability in Bangladeshi healthy male and female

2016 ◽  
Vol 43 (3) ◽  
pp. 146-150
Author(s):  
Qazi Farzana Akhter ◽  
Qazi Shamima Akhter ◽  
Farhana Rahman ◽  
Sybilla Ferdousi ◽  
Susmita Sinha
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
High Frequency ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Autonomic Nerve ◽  
Age Group ◽  
Power Spectral

Heart rate variability (HRV) has been considered as an indicator of autonomic nerve function status. We aimed to find out the reference values of heart rate variability by power spectral analysis in our healthy population of both sex. This cross sectional study was conducted in the Department of Physiology, Dhaka Medical College, Dhaka from the period of July 2012 to June 2013. For this, 180 subjects were selected with the age ranging from 15-60 years. All the study subjects were divided into 3 different groups according to age (Group A: 15-30 years; Group B: 31-45 years; Group C: 46-60 years). Each group contained 60 subjects of which 30 were male and 30 were female. Analysis of HRV parameters were done in Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka. Systolic blood pressure, diastolic blood pressure, low frequency normalized unit, low frequency / high frequency ratio were significantly higher in male than female. Again high frequency power, high frequency normalized unit were significantly higher in female than male of same age group. This study concludes that male showed higher cardiac sympathetic activities while female showed higher cardiac parasympathetic activities in different age groups.Bangladesh Med J. 2014 Sep; 43 (3): 146-150

scholarly journals Slithering CSF: Cerebrospinal Fluid Dynamics in the Stationary and Moving Viper Boa, Candoia aspera

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 672
Author(s):  
Bruce A. Young ◽  
Skye Greer ◽  
Michael Cramberg
Keyword(s):  
Cerebrospinal Fluid ◽  
Cardiac Cycle ◽  
Low Frequency ◽  
Mean Amplitude ◽  
The Body ◽  
Body Waves ◽  
Lower Amplitude ◽  
Lateral Undulation ◽  
Recovery From Anesthesia ◽  
The Relationship

In the viper boa (Candoia aspera), the cerebrospinal fluid (CSF) shows two stable overlapping patterns of pulsations: low-frequency (0.08 Hz) pulses with a mean amplitude of 4.1 mmHg that correspond to the ventilatory cycle, and higher-frequency (0.66 Hz) pulses with a mean amplitude of 1.2 mmHg that correspond to the cardiac cycle. Manual oscillations of anesthetized C. aspera induced propagating sinusoidal body waves. These waves resulted in a different pattern of CSF pulsations with frequencies corresponding to the displacement frequency of the body and with amplitudes greater than those of the cardiac or ventilatory cycles. After recovery from anesthesia, the snakes moved independently using lateral undulation and concertina locomotion. The episodes of lateral undulation produced similar influences on the CSF pressure as were observed during the manual oscillations, though the induced CSF pulsations were of lower amplitude during lateral undulation. No impact on the CSF was found while C. aspera was performing concertina locomotion. The relationship between the propagation of the body and the CSF pulsations suggests that the body movements produce an impulse on the spinal CSF.

Heart rate variability and baroreflex sensitivity are reduced in chronically undernourished, but otherwise healthy, human subjects

2003 ◽  
Vol 104 (3) ◽  
pp. 295-302 ◽  
Author(s):  
Mario VAZ ◽  
A.V. BHARATHI ◽  
S. SUCHARITA ◽  
D. NAZARETH
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Baroreflex Sensitivity ◽  
Human Subjects ◽  
Normal Weight ◽  
Autonomic Nerve ◽  
Total Power ◽  
Healthy Human ◽  
Frequency Power

Alterations in autonomic nerve activity in subjects in a chronically undernourished state have been proposed, but have been inadequately documented. The present study evaluated heart rate and systolic blood pressure variability in the frequency domain in two underweight groups, one of which was undernourished and recruited from the lower socio-economic strata [underweight, undernourished (UW/UN); n = 15], while the other was from a high class of socio-economic background [underweight, well nourished (UW/WN); n = 17], as well as in normal-weight controls [normal weight, well nourished (NW/WN); n = 27]. Baroreflex sensitivity, which is a determinant of heart rate variability, was also assessed. The data indicate that total power (0–0.4Hz), low-frequency power (0.04–0.15Hz) and high-frequency power (0.15–0.4Hz) of RR interval variability were significantly lower in the UW/UN subjects (P<0.05) than in the NW/WN controls when expressed in absolute units, but not when the low- and high-frequency components were normalized for total power. Baroreflex sensitivity was similarly lower in the UW/UN group (P<0.05). Heart rate variability parameters in the UW/WN group were generally between those of the UW/UN and NW/WN groups, but were not statistically different from either. The mechanisms that contribute to the observed differences between undernourished and normal-weight groups, and the implications of these differences, remain to be elucidated.

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