Influence of head-down and lateral decubitus neck flexion on heart rate variability

2001 ◽  
Vol 90 (1) ◽  
pp. 127-132 ◽  
Author(s):  
C. Matthew Lee ◽  
Robert H. Wood ◽  
Michael A. Welsch

The purpose of this study was to examine the response of heart rate variability (HRV), a noninvasive index of autonomic control, to head-down neck flexion (HDNF), which engages both otoliths and neck muscle afferents, and to lateral decubitus neck flexion (LNF), in which neck afferents are activated, whereas otolith afferent input is not. HRV and forearm blood flow were evaluated in participants lying prone, during HDNF, lying in the lateral decubitus position, and during LNF. Compared with the prone position, HDNF resulted in lower high-frequency (46.9 ± 7.1 vs. 62.3 ± 6.2) and higher low-frequency (53.1 ± 7.1 vs. 37.7 ± 6.2) power, expressed as normalized units, along with higher low-frequency-to-high-frequency ratio (1.65 ± 0.3 vs. 0.78 ± 0.2), whereas LNF resulted in no alterations in HRV indexes. Furthermore, there were no significant differences in forearm blood flow or vascular resistance among any of the positions. Our data suggest that otolith organs influence autonomic modulation of the heart, supporting previous studies reporting that HDNF elicits increased sympathetic outflow. These data further suggest that HDNF results in a parasympathetic withdrawal from the heart in addition to sympathetic activation.

Author(s):  
Б.И. Кузник ◽  
Ю.Н. Смоляков ◽  
Е.С. Гусева ◽  
С.О. Давыдов ◽  
И.В. Файн

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Reuben Howden ◽  
Eva Gougian ◽  
Marcus Lawrence ◽  
Samantha Cividanes ◽  
Wesley Gladwell ◽  
...  

Nrf2protects the lung from adverse responses to oxidants, including 100% oxygen (hyperoxia) and airborne pollutants like particulate matter (PM) exposure, but the role ofNrf2on heart rate (HR) and heart rate variability (HRV) responses is not known. We hypothesized that genetic disruption ofNrf2would exacerbate murine HR and HRV responses to severe hyperoxia or moderate PM exposures.Nrf2-/-andNrf2+/+mice were instrumented for continuous ECG recording to calculate HR and HRV (low frequency (LF), high frequency (HF), and total power (TP)). Mice were then either exposed to hyperoxia for up to 72 hrs or aspirated with ultrafine PM (UF-PM). Compared to respective controls, UF-PM induced significantly greater effects on HR (P<0.001) and HF HRV (P<0.001) inNrf2-/-mice compared toNrf2+/+mice.Nrf2-/-mice tolerated hyperoxia significantly less thanNrf2+/+mice (~22 hrs;P<0.001). Reductions in HR, LF, HF, and TP HRV were also significantly greater inNrf2-/-compared toNrf2+/+mice (P<0.01). Results demonstrate thatNrf2deletion increases susceptibility to change in HR and HRV responses to environmental stressors and suggest potential therapeutic strategies to prevent cardiovascular alterations.


2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Joanne W. Y. Chung ◽  
Vincent C. M. Yan ◽  
Hongwei Zhang

Aim.To summarize all relevant trials and critically evaluate the effect of acupuncture on heart rate variability (HRV).Method.This was a systematic review with meta-analysis. Keyword search was conducted in 7 databases for randomized controlled trials (RCTs). Data extraction and risk of bias were done.Results.Fourteen included studies showed a decreasing effect of acupuncture on low frequency (LF) and low frequency to high frequency ratio (LF/HF ratio) of HRV for nonhealthy subjects and on normalized low frequency (LF norm) for healthy subjects. The overall effect was in favour of the sham/control group for high frequency (HF) in nonhealthy subjects and for normalized high frequency (HF norm) in healthy subjects. Significant decreasing effect on HF and LF/HF ratio of HRV when acupuncture was performed on ST36 among healthy subjects and PC6 among both healthy and nonhealthy subjects, respectively.Discussion.This study partially supports the possible effect of acupuncture in modulating the LF of HRV in both healthy and nonhealthy subjects, while previous review reported that acupuncture did not have any convincing effect on HRV in healthy subjects. More published work is needed in this area to determine if HRV can be an indicator of the therapeutic effect of acupuncture.


1997 ◽  
Vol 92 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Gervais Tougas ◽  
Markad Kamath ◽  
Geena Watteel ◽  
Debbie Fitzpatrick ◽  
Ernest L. Fallen ◽  
...  

1. The heart and the oesophagus have similar sensory pathways, and sensations originating from the oesophagus are often difficult to differentiate from those of cardiac origin. We hypothesized that oesophageal sensory stimuli could alter neurocardiac function through autonomic reflexes elicited by these oesophageal stimuli. In the present study, we examined the neurocardiac response to oesophageal stimulation and the effects of electrical and mechanical oesophageal stimulation on the power spectrum of beat-to-beat heart rate variability in male volunteers. 2. In 14 healthy volunteers, beat-to-beat heart rate variability was compared at rest and during oesophageal stimulation, using either electrical (200 μs, 16 mA, 0.2 Hz) or mechanical (0.5 s, 14 ml, 0.2 Hz) stimuli. The power spectrum of beat-to-beat heart rate variability was obtained and its low- and high-frequency components were determined. 3. Distal oesophageal stimulation decreased heart rate slightly (both electrical and mechanical) (P < 0.005), and markedly altered heart rate variability (P < 0.001). Both electrical and mechanical oesophageal stimulation increased the absolute and normalized area of the high-frequency band within the power spectrum (P < 0.001), while simultaneously decreasing the low-frequency power (P < 0.005). 4. In humans, oesophageal stimulation, whether electrical or mechanical, appears to amplify respiratory-driven cardiac vagoafferent modulation while decreasing sympathetic modulation. The technique provides access to vagoafferent fibres and thus may yield useful information on the autonomic effects of visceral or oesophageal sensory stimulation.


2015 ◽  
Vol 22 (8) ◽  
pp. 1080-1085 ◽  
Author(s):  
Sakari Simula ◽  
Tomi Laitinen ◽  
Tiina M Laitinen ◽  
Tuula Tarkiainen ◽  
Päivi Hartikainen ◽  
...  

Background: Fingolimod modulates sphingosine-1-phosphate receptors that are also found in cardiovascular tissue. Objective: To investigate the effects of fingolimod on cardiac autonomic regulation prospectively. Methods: Twenty-seven relapsing–remitting multiple sclerosis patients underwent 24-hour electrocardiogram recording before, at the first day of fingolimod treatment (1d) and after three months of continuous dosing (3mo). The time interval between two consecutive R-peaks (RR-interval) was measured. Cardiac autonomic regulation was assessed by the various parameters of heart rate variability. Parasympathetic stimulation prolongs the RR-interval and increases heart rate variability while the effects of sympathetic stimulation are mainly the opposite. The low frequency/high frequency ratio reflects sympathovagal balance. Results: From baseline to 1d, a prolongation of the RR-interval ( P<0.001), an increase in the values of various heart rate variability parameters ( P<0.05 to P<0.001) and a decrease in the low frequency/high frequency ratio ( P<0.05) were demonstrated. At 3mo, although the RR-interval remained longer ( P<0.01), the values of various heart rate variability parameters were lower ( P<0.01 to P<0.001) as compared to baseline. At 3mo, the low frequency/high frequency ratio ( P<0.05) was higher in men than in women although no such difference was found at baseline or at 1d. Conclusions: After an initial increase in parasympathetic regulation, continuous fingolimod dosing shifts cardiac autonomic regulation towards sympathetic predominance, especially in men. Careful follow-up of fingolimod-treated relapsing–remitting multiple sclerosis patients is warranted as sympathetic predominance associates generally with impaired outcome. ClinicalTrials.cov: NCT01704183


2019 ◽  
Vol 18 (8) ◽  
pp. 658-666 ◽  
Author(s):  
Ching-Hsiang Chen ◽  
Kuo-Sheng Hung ◽  
Yu-Chu Chung ◽  
Mei-Ling Yeh

Background: Stroke, a medical condition that causes physical disability and mental health problems, impacts negatively on quality of life. Post-stroke rehabilitation is critical to restoring quality of life in these patients. Objectives: This study was designed to evaluate the effect of a mind–body interactive qigong intervention on the physical and mental aspects of quality of life, considering bio-physiological and mental covariates in subacute stroke inpatients. Methods: A randomized controlled trial with repeated measures design was used. A total of 68 participants were recruited from the medical and rehabilitation wards at a teaching hospital in northern Taiwan and then randomly assigned either to the Chan-Chuang qigong group, which received standard care plus a 10-day mind–body interactive exercise program, or to the control group, which received standard care only. Data were collected using the National Institutes of Health Stroke Scale, Hospital Anxiety and Depression Scale, Short Form-12, stroke-related neurologic deficit, muscular strength, heart rate variability and fatigue at three time points: pre-intervention, halfway through the intervention (day 5) and on the final day of the intervention (day 10). Results: The results of the mixed-effect model analysis showed that the qigong group had a significantly higher quality of life score at day 10 ( p<0.05) than the control group. Among the covariates, neurologic deficit ( p=0.04), muscle strength ( p=0.04), low frequency to high frequency ratio ( p=0.02) and anxiety ( p=0.04) were significantly associated with changes in quality of life. Conversely, heart rate, heart rate variability (standard deviation of normal-to-normal intervals, low frequency and high frequency), fatigue and depression were not significantly associated with change in quality of life ( p >0.05). Conclusions: This study supports the potential benefits of a 10-day mind–body interactive exercise (Chan-Chuang qigong) program for subacute stroke inpatients and provides information that may be useful in planning adjunctive rehabilitative care for stroke inpatients.


1996 ◽  
Vol 271 (2) ◽  
pp. H455-H460 ◽  
Author(s):  
K. P. Davy ◽  
N. L. Miniclier ◽  
J. A. Taylor ◽  
E. T. Stevenson ◽  
D. R. Seals

Coronary heart disease (CHD) and cardiac sudden death (CSD) incidence accelerates after menopause, but the incidence is lower in physically active versus less active women. Low heart rate variability (HRV) is a risk factor for CHD and CSD. The purpose of the present investigation was to test the hypothesis that HRV at rest is greater in physically active compared with less active postmenopausal women. If true, we further hypothesized that the greater HRV in the physically active women would be closely associated with an elevated spontaneous cardiac baroreflex sensitivity (SBRS). HRV (both time and frequency domain measures) and SBRS (sequence method) were measured during 5-min periods of controlled frequency breathing (15 breaths/min) in the supine, sitting, and standing postures in 9 physically active postmenopausal women (age = 53 +/- 1 yr) and 11 age-matched controls (age = 56 +/- 2 yr). Body weight, body mass index, and body fat percentage were lower (P < 0.01) and maximal oxygen uptake was higher (P < 0.01) in the physically active group. The standard deviation of the R-R intervals (time domain measure) was higher in all postures in the active women (P < 0.05) as were the high-frequency, low-frequency, and total power of HRV. SBRS also was higher (P < 0.05) in the physically active women in all postures and accounted for approximately 70% of the variance in the high-frequency power of HRV (P < 0.05). The results of the present investigation indicate that physically active postmenopausal women demonstrate higher levels of HRV compared with age-matched, less active women. Furthermore, SBRS accounted for the majority of the variance in the high-frequency power of HRV, suggesting the possibility of a mechanistic link with cardiac vagal modulation of heart rate. Our findings may provide insight into a possible cardioprotective mechanism in physically active postmenopausal women.


2016 ◽  
Vol 20 (3) ◽  
pp. 975-985 ◽  
Author(s):  
Ren-Jing Huang ◽  
Ching-Hsiang Lai ◽  
Shin-Da Lee ◽  
Wei-Che Wang ◽  
Ling-Hui Tseng ◽  
...  

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

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


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


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