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Heart rate variability comparison between young males after 4-6 weeks from the end of SARS-CoV-2 infection and controls. Sci Rep 2022; 12:8832. [PMID: 35614330 PMCID: PMC9130989 DOI: 10.1038/s41598-022-12844-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 05/11/2022] [Indexed: 11/11/2022] Open
Abstract
Due to the prolonged inflammatory process induced by infection of the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), indices of autonomic nervous system dysfunction may persist long after viral shedding. Previous studies showed significant changes in HRV parameters in severe (including fatal) infection of SARS-CoV-2. However, few studies have comprehensively examined HRV in individuals who previously presented as asymptomatic or mildly symptomatic cases of COVID-19. In this study, we examined HRV in asymptomatic or mildly symptomatic individuals 5–7 weeks following positive confirmation of SARS-CoV-2 infection. Sixty-five ECG Holter recordings from young (mean age 22.6 ± 3.4 years), physically fit male subjects 4–6 weeks after the second negative test (considered to be the start of recovery) and twenty-six control male subjects (mean age 23.2 ± 2.9 years) were considered in the study. Night-time RR time series were extracted from ECG signals. Selected linear as well as nonlinear HRV parameters were calculated. We found significant differences in Porta’s symbolic analysis parameters V0 and V2 (p < 0.001), α2 (p < 0.001), very low-frequency component (VLF; p = 0.022) and respiratory peak (from the PRSA method; p = 0.012). These differences may be caused by the changes of activity of the parasympathetic autonomic nervous system as well as by the coupling of respiratory rhythm with heart rate due to an increase in pulmonary arterial vascular resistance. The results suggest that the differences with the control group in the HRV parameters, that reflect the functional state of the autonomic nervous system, are measurable after a few weeks from the beginning of the recovery even in the post-COVID group—a young and physically active population. We indicate HRV sensitive markers which may be used in long-term monitoring of patients after recovery.
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Khodadadi F, Ketabchi F, Khodabandeh Z, Tavassoli A, Lewis GF, Bahaoddini A. The effect of subdiaphragmatic vagotomy on heart rate variability and lung inflammation in rats with severe hemorrhagic shock. BMC Cardiovasc Disord 2022; 22:181. [PMID: 35439928 PMCID: PMC9020113 DOI: 10.1186/s12872-022-02594-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/28/2022] [Indexed: 11/10/2022] Open
Abstract
Background The influence of cutting the sub-diaphragmatic branch of the vagus nerve on heart rate variability (HRV) and inflammatory reaction to severe hemorrhagic shock has not been determined prior to this study. Methods Male Sprague–Dawley rats were divided into four groups of Sham, sub-diaphragmatic vagotomized (Vag), subacute (135 ± 2 min) hemorrhagic shock (SHS), and sub-diaphragmatic vagotomized with SHS (Vag + SHS). Hemodynamic parameters were recorded and HRV calculated during multiple phases in a conscious model of hemorrhagic shock. The expressions of TNF-α and iNOS were measured in the spleen and lung tissues at the conclusion of the protocol. Results Decreases in blood pressure during blood withdrawal were identical in the SHS and Vag + SHS groups. However, heart rate only decreased in the Nadir-1 phase of the SHS group. HRV indicated increased power in the very-low, low, and high (VLF, LF, and HF) frequency bands during the Nadir-1 phase of the SHS and Vag + SHS groups, albeit the values were higher in the SHS group. In the recovery phase, the HF bands were only lower in the SHS group. After hemorrhagic shock followed by resuscitation, the expression of TNF-α and iNOS increased in the spleen and lung of the SHS group, and the expression of these genes was significantly lower in the Vag + SHS group than in the SHS group. Conclusion Parasympathetic activity increases during the hypotensive phase of hemorrhagic shock, whereas the cardiac vagal tone decreases in the recovery phase. Sub-diapragmatic vagotomy blunts the cardiac vagal tone during hemorrhagic shock, but its effect is reversed in the recovery phase. The vagus nerve plays a role in proinflammatory responses in the lungs and spleen in subacute hemorrhagic shock followed by resuscitation.
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Affiliation(s)
- Fateme Khodadadi
- Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Farzaneh Ketabchi
- Department of Physiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Khodabandeh
- Stem Cell Technology Research Center, Shiraz University of Medical Science, Shiraz, Iran
| | - Alireza Tavassoli
- Department of Pathology, Fasa University of Medical Sciences, Fasa, Iran
| | - Gregory F Lewis
- Intelligent Systems Engineering, Indiana University, Bloomington, IN, USA.,The Traumatic Stress Research Consortium at the Kinsey Institute, Indiana University, Bloomington, IN, USA
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3
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Zaccaro A, Piarulli A, Melosini L, Menicucci D, Gemignani A. Neural Correlates of Non-ordinary States of Consciousness in Pranayama Practitioners: The Role of Slow Nasal Breathing. Front Syst Neurosci 2022; 16:803904. [PMID: 35387390 PMCID: PMC8977447 DOI: 10.3389/fnsys.2022.803904] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 02/17/2022] [Indexed: 12/24/2022] Open
Abstract
The modulatory effect of nasal respiration on integrative brain functions and hence consciousness has recently been unambiguously demonstrated. This effect is sustained by the olfactory epithelium mechanical sensitivity complemented by the existence of massive projections between the olfactory bulb and the prefrontal cortex. However, studies on slow nasal breathing (SNB) in the context of contemplative practices have sustained the fundamental role of respiratory vagal stimulation, with little attention to the contribution of the olfactory epithelium mechanical stimulation. This study aims at disentangling the effects of olfactory epithelium stimulation (proper of nasal breathing) from those related to respiratory vagal stimulation (common to slow nasal and mouth breathing). We investigated the psychophysiological (cardio-respiratory and electroencephalographic parameters) and phenomenological (perceived state of consciousness) aftereffects of SNB (epithelium mechanical – 2.5 breaths/min) in 12 experienced meditators. We compared the nasal breathing aftereffects with those observed after a session of mouth breathing at the same respiratory rate and with those related to a resting state condition. SNB induced (1) slowing of electroencephalography (EEG) activities (delta-theta bands) in prefrontal regions, (2) a widespread increase of theta and high-beta connectivity complemented by an increase of phase-amplitude coupling between the two bands in prefrontal and posterior regions belonging to the Default Mode Network, (3) an increase of high-beta networks small-worldness. (4) a higher perception of being in a non-ordinary state of consciousness. The emerging scenario strongly suggests that the effects of SNB, beyond the relative contribution of vagal stimulation, are mainly ascribable to olfactory epithelium stimulation. In conclusion, slow Pranayama breathing modulates brain activity and hence subjective experience up to the point of inducing a non-ordinary state of consciousness.
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Affiliation(s)
- Andrea Zaccaro
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
- Department of Neuroscience, Imaging and Clinical Sciences, “G. d’Annunzio” University of Chieti-Pescara, Chieti, Italy
| | - Andrea Piarulli
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
- Giga Consciousness, Coma Science Group, University of Liège, Liège, Belgium
- *Correspondence: Andrea Piarulli,
| | - Lorenza Melosini
- Pneumology Branch, Azienda Ospedaliero Universitaria Pisana, Pisa, Italy
| | - Danilo Menicucci
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Angelo Gemignani
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
- Clinical Psychology Branch, Azienda Ospedaliero Universitaria Pisana, Pisa, Italy
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4
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Lensen IS, Monfredi OJ, Andris RT, Lake DE, Moorman JR. Heart rate fragmentation gives novel insights into non-autonomic mechanisms governing beat-to-beat control of the heart's rhythm. JRSM Cardiovasc Dis 2020; 9:2048004020948732. [PMID: 32922768 PMCID: PMC7457638 DOI: 10.1177/2048004020948732] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 07/15/2020] [Accepted: 07/17/2020] [Indexed: 12/17/2022] Open
Abstract
To demonstrate how heart rate fragmentation gives novel insights into
non-autonomic mechanisms of beat-to-beat variability in cycle length, and
predicts survival of cardiology clinic patients, over and above traditional
clinical risk factors and measures of heart rate variability. Approach: We studied 2893 patients seen by cardiologists with
clinical data including 24-hour Holter monitoring. Novel measures of heart
rate fragmentation alongside canonical time and frequency domain measures of
heart rate variability, as well as an existing local dynamics score were
calculated. A proportional hazards model was utilized to relate the results
to survival. Main results: The novel heart rate fragmentation measures were
validated and characterized with respect to the effects of age, ectopy and
atrial fibrillation. Correlations between parameters were determined.
Critically, heart rate fragmentation results could not be accounted for by
undersampling respiratory sinus arrhythmia. Increased heart rate
fragmentation was associated with poorer survival (p ≪ 0.01 in the
univariate model). In multivariable analyses, increased heart rate
fragmentation and more abnormal local dynamics (p 0.045), along with
increased clinical risk factors (age (p ≪ 0.01), tobacco use (p ≪ 0.01) and
history of heart failure (p 0.019)) and lower low- to high-frequency ratio
(p 0.022) were all independent predictors of 2-year mortality. Significance: Analysis of continuous ECG data with heart rate
fragmentation indices yields information regarding non-autonomic control of
beat-to-beat variability in cycle length that is independent of and additive
to established parameters for investigating heart rate variability, and
predicts mortality in concert with measures of local dynamics, frequency
content of heart rate, and clinical risk factors.
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Affiliation(s)
- Irene S Lensen
- University of Technology Eindhoven, Noord-Brabant, Netherlands
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5
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Ghali MGZ, Ghali GZ. Mechanisms Contributing to the Generation of Mayer Waves. Front Neurosci 2020; 14:395. [PMID: 32765203 PMCID: PMC7381285 DOI: 10.3389/fnins.2020.00395] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 03/30/2020] [Indexed: 01/25/2023] Open
Abstract
Mayer waves may synchronize overlapping propriobulbar interneuronal microcircuits constituting the respiratory rhythm and pattern generator, sympathetic oscillators, and cardiac vagal preganglionic neurons. Initially described by Sir Sigmund Mayer in the year 1876 in the arterial pressure waveform of anesthetized rabbits, authors have since extensively observed these oscillations in recordings of hemodynamic variables, including arterial pressure waveform, peripheral resistance, and blood flow. Authors would later reveal the presence of these oscillations in sympathetic neural efferent discharge and brainstem and spinal zones corresponding with sympathetic oscillators. Mayer wave central tendency proves highly consistent within, though the specific frequency band varies extensively across, species. Striking resemblance of the Mayer wave central tendency to the species-specific baroreflex resonant frequency has led the majority of investigators to comfortably presume, and generate computational models premised upon, a baroreflex origin of these oscillations. Empirical interrogation of this conjecture has generated variable results and derivative interpretations. Sinoaortic denervation and effector sympathectomy variably reduces or abolishes spectral power contained within the Mayer wave frequency band. Refractorines of Mayer wave generation to barodeafferentation lends credence to the hypothesis these waves are chiefly generated by brainstem propriobulbar and spinal cord propriospinal interneuronal microcircuit oscillators and likely modulated by the baroreflex. The presence of these waves in unitary discharge of medullary lateral tegmental field and rostral ventrolateral medullary neurons (contemporaneously exhibiting fast sympathetic rhythms [2-6 and 10 Hz bands]) in spectral variability in vagotomized pentobarbital-anesthetized and unanesthetized midcollicular (i.e., intercollicular) decerebrate cats supports genesis of Mayer waves by supraspinal sympathetic microcircuit oscillators. Persistence of these waves following high cervical transection in vagotomized unanesthetized midcollicular decerebrate cats would seem to suggest spinal sympathetic microcircuit oscillators generate these waves. The widespread presence of Mayer waves in brainstem sympathetic-related and non-sympathetic-related cells would seem to betray a general tendency of neurons to oscillate at this frequency. We have thus presented an extensive and, hopefully cohesive, discourse evaluating, and evolving the interpretive consideration of, evidence seeking to illumine our understanding of origins of, and insight into mechanisms contributing to, the genesis of Mayer waves. We have predicated our arguments and conjectures in the substance and matter of empirical data, though we have occasionally waxed philosophical beyond these traditional confines in suggesting interpretations exceeding these limits. We believe our synthesis and interpretation of the relevant literature will fruitfully inspire future studies from the perspective of a more intimate appreciation and conceptualization of network mechanisms generating oscillatory variability in neuronal and neural outputs. Our evaluation of Mayer waves informs a novel set of disciplines we term quantum neurophysics extendable to describing subatomic reality. Beyond informing our appreciation of mechanisms generating sympathetic oscillations, Mayer waves may constitute an intrinsic property of neurons extant throughout the cerebrum, brainstem, and spinal cord or reflect an emergent property of interactions between arteriogenic and neuronal oscillations.
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Affiliation(s)
- Michael G Z Ghali
- Department of Neurological Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroscience, University of Helsinki, Helsinki, Finland.,Department of Neurological Surgery, University of Oslo, Olso, Norway.,Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States.,Department of Neurological Surgery, Barrow Neurological Institute, Phoenix, AZ, United States.,Department of Neurological Surgery, Johns Hopkins Medical Institute, Baltimore, MD, United States
| | - George Z Ghali
- Department of Neurological Surgery, Karolinska Institutet, Stockholm, Sweden.,United States Environmental Protection Agency, Arlington, VA, United States.,Department of Toxicology, Purdue University, West Lafayette, IN, United States
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Soliński M, Kuklik P, Gierałtowski J, Baranowski R, Graff B, Żebrowski J. The effect of persistent U-shaped patterns in RR night-time series on the heart rate variability complexity in healthy humans. Physiol Meas 2020; 41:065001. [DOI: 10.1088/1361-6579/ab9376] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Abstract
There is a bidirectional relationship between affective disorders and cardiovascular abnormalities, often described as a downward spiral, whereas major depressive disorders (MDD, and anxiety disorders) significantly increase the risk of developing cardiovascular diseases (CVD); CVD are also associated with increased risk of developing MDD (and anxiety disorders). Moreover, the prognosis and progression of CVD is significantly worsened in the presence of MDD. Heart rate variability (HRV) has often been suggested as a potential mediator in this comorbidity. In this review, we discuss HRV alterations in MDD. However, we mainly focus on the direct relationship between HRV alterations and psychiatric symptoms, rather than its relationship with CVD, as this has been reviewed elsewhere. After a general introduction to HRV and how it can be measured, we review how HRV is altered in MDD. We subsequently describe how antidepressant drugs affect HRV, showing that some classes (such as tricyclics) generally worsen HRV, whereas others (most notably selective serotonin reuptake inhibitors) have a more positive influence. We also review the effects of several other treatments, with a special focus on vagal nerve stimulation, finishing with some further considerations and recommendation for further research, both in humans and animals.
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8
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Wdowczyk J, Makowiec D, Gruchała M, Wejer D, Struzik ZR. Dynamical Landscape of Heart Rhythm in Long-Term Heart Transplant Recipients: A Way to Discern Erratic Rhythms. Front Physiol 2018; 9:274. [PMID: 29686620 PMCID: PMC5900061 DOI: 10.3389/fphys.2018.00274] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 03/08/2018] [Indexed: 12/26/2022] Open
Abstract
It is commonly believed that higher values of heart rate variability (HRV) indices account for better organization of the network of feedback reflexes driving an organism's response to actual bodily needs. In order to evaluate this organization in heart transplant (HTX) recipients, 58 nocturnal Holter signals of 14 HTX patients were analyzed. Their dynamical properties were evaluated by short-term HRV indices and measures grounded on entropy. Estimates grouped according to the patients' clinical progress: free of complications versus with complications, and arranged in order of the length of time since the HTX, lead us to the conclusion that higher HRV is associated with a worse outcome for HTX patients. Moreover, short-term HRV indices that are constant, rather than increasing over time, serve well in the prognosis of the future state of a HTX patient. These findings suggest that increases observed in HRV indices are related to erratic rhythms resulting from remodeling of the cardiac tissue (including heterogeneous innervation) in long-term HTX patients. Therefore, we hypothesize that dynamical landscape markers (entropy and fragmentation measures together with the short-term HRV indices) can serve as a tool in the exploration of the genesis of (non-respiratory sinus) arrhythmia.
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Affiliation(s)
- Joanna Wdowczyk
- First Cardiology Clinic, Medical University of Gdańsk, Gdańsk, Poland
| | - Danuta Makowiec
- Faculty of Mathematics, Physics and Informatics, Institute of Theoretical Physics and Astrophysics, University of Gdańsk, Gdańsk, Poland
| | - Marcin Gruchała
- First Cardiology Clinic, Medical University of Gdańsk, Gdańsk, Poland
| | - Dorota Wejer
- Faculty of Mathematics, Physics and Informatics, Institute of Experimental Physics, University of Gdańsk, Gdańsk, Poland
| | - Zbigniew R Struzik
- Laboratory for Advanced Brain Signal Processing, RIKEN Brain Science Institute, Wako, Japan.,Graduate School of Education, University of Tokyo, Tokyo, Japan
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Ciliberti MAP, Santoro F, Di Martino LFM, Rinaldi AC, Salvemini G, Cipriani F, Triggiani AI, Moscatelli F, Valenzano A, Di Biase M, Brunetti ND, Cibelli G. Predictive value of very low frequency at spectral analysis among patients with unexplained syncope assessed by head-up tilt testing. Arch Cardiovasc Dis 2017; 111:95-100. [PMID: 28958870 DOI: 10.1016/j.acvd.2017.04.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 04/19/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND The role of heart rate variability (HRV) in the prediction of vasovagal syncope during head-up tilt testing (HUTt) is unclear. AIM To evaluate the ability of the spectral components of HRV at rest to predict vasovagal syncope among patients with unexplained syncope referred for HUTt. METHODS Twenty-six consecutive patients with unexplained syncope were enrolled in the study. All patients underwent HRV evaluation at rest (very low frequency [VLF], low frequency [LF], high frequency [HF] and LF/HF ratio) and during HUTt. HUTt was performed using the Westminster protocol. Continuous electrocardiogram and blood pressure monitoring were performed throughout the test. RESULTS Eight (31%) patients developed syncope during HUTt. There were no baseline differences in terms of clinical features and HRV variables among patients who developed syncope and those who did not, except for VLF (2421 vs 896ms2; P<0.001). In the multivariable logistic regression analysis, including age and sex, VLF was the only independent variable associated with syncope during HUTt (odds ratio 1.002, 95% confidence interval 1.0003-1.0032; P=0.02). The area under the curve at rest was 0.889 for VLF, 0.674 for HF and 0.611 for LF. A value of VLF>2048ms2 was the optimal cut-off to predict syncope during HUTt (sensitivity 87.5%, specificity 72.2%). CONCLUSIONS VLF at rest predicted the incidence of syncope during HUTt. Further studies are warranted to confirm these preliminary data.
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Affiliation(s)
| | - Francesco Santoro
- Department of Medical & Surgical Sciences, University of Foggia, viale Pinto 1, 71122 Foggia, Italy
| | | | - Antonio Cosimo Rinaldi
- Department of Medical & Surgical Sciences, University of Foggia, viale Pinto 1, 71122 Foggia, Italy
| | - Giuseppe Salvemini
- Department of Medical & Surgical Sciences, University of Foggia, viale Pinto 1, 71122 Foggia, Italy
| | - Francesco Cipriani
- Department of Medical & Surgical Sciences, University of Foggia, viale Pinto 1, 71122 Foggia, Italy
| | | | - Fiorenzo Moscatelli
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy; Department of Motor, Human and Health Sciences, University of Rome "Foro Italico", 00197 Rome, Italy
| | - Anna Valenzano
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy
| | - Matteo Di Biase
- Department of Medical & Surgical Sciences, University of Foggia, viale Pinto 1, 71122 Foggia, Italy
| | - Natale Daniele Brunetti
- Department of Medical & Surgical Sciences, University of Foggia, viale Pinto 1, 71122 Foggia, Italy.
| | - Giuseppe Cibelli
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy
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Mizuno T, Tamakoshi K, Tanabe K. Anxiety during pregnancy and autonomic nervous system activity: A longitudinal observational and cross-sectional study. J Psychosom Res 2017; 99:105-111. [PMID: 28712414 DOI: 10.1016/j.jpsychores.2017.06.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/26/2017] [Accepted: 06/07/2017] [Indexed: 01/15/2023]
Abstract
OBJECTIVES To assess the longitudinal change in autonomic nervous system (ANS) activity during pregnancy and the association between anxiety during pregnancy and ANS activity. METHODS Pregnant Japanese women with a singleton fetus and normal pregnancy were recruited (n=65). ANS activity and anxiety were measured using a self-rating questionnaire at approximately 20, 30, and 36weeks of gestation. Very low (VLF) and high (HF) frequency bands of heart rate variability spectrums were used. Anxiety was assessed using the Japanese version of the State-Trait Anxiety Inventory. A score of 45 or more on trait-anxiety and the other represent the trait-anxiety group and the non- trait-anxiety group, respectively. The state-anxiety group and the non-state-anxiety group were defined in the same manner. RESULTS Longitudinal observation of individual pregnant women indicated the significant increasing trend (p=0.002) of VLF power and the significant decreasing trend (p<0.001) of HF power during 20 to 36 gestation weeks. Compared with the non-trait-anxiety group, the trait-anxiety group had significantly lower VLF values at 20 gestational weeks (p=0.033) and had significantly lower HF values at 30 and 36 gestational weeks (p=0.015 and p=0.044, respectively). The increasing rate of VLF from 20 to 36 gestational weeks was higher among the trait-anxiety group. The same associations were observed between the state-anxiety and non-state-anxiety groups at 20 gestational weeks. CONCLUSIONS Anxiety during pregnancy decreased heart rate variability. Anxiety in second trimester pregnancy promoted a subsequent increase in sympathetic activity.
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Affiliation(s)
- Taeko Mizuno
- Department of Nursing, Nagoya University Graduate, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya City, Aichi Prefecture, Japan.
| | - Koji Tamakoshi
- Department of Nursing, Nagoya University Graduate, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya City, Aichi Prefecture, Japan.
| | - Keiko Tanabe
- School of Medicine, Graduate School of Nursing, Aichi Medical University, 1-1 Yazakokarimata, Nagakute City, Aichi Prefecture, Japan.
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11
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Simmons EE, Bergeron ER, Florian JP. The impact of repetitive long-duration water immersion on vascular function. PLoS One 2017; 12:e0181673. [PMID: 28750006 PMCID: PMC5531465 DOI: 10.1371/journal.pone.0181673] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 07/04/2017] [Indexed: 01/11/2023] Open
Abstract
While physiological responses to water immersion (WI) are well-studied, the vascular responses after WI are less understood. Fifteen male subjects performed six-hour resting thermoneutral water immersions (WI) at 1.35 atmospheres absolute for four consecutive days, with follow-up on the fifth day. Measurements included peripheral endothelial function and augmentation index (PAT, peripheral arterial tonometry), beat-to-beat blood pressure (BP, photoplethysmography), heart rate (HR), and plasma volume (PV) calculated from changes in hemoglobin and hematocrit. The reactive hyperemia index (RHI), a marker of peripheral endothelial function, increased with repeated immersions (p = 0.008). By WI2 and WI3, RHI increased 12% and 16%, respectively, compared to WI1 values, but no significant differences were detected between WI4 and WI1 for either measure. Absolute augmentation index (AI) increased by an average of 33% (p<0.001) and AI normalized for HR (AI@75) by 11% (p = 0.12) following each WI. PV decreased significantly by 13.2% following WI and remained 6.8% lower at follow-up compared to pre-WI. Systolic blood pressure significantly decreased by an average of 2.5% following each WI (p = 0.012). Compared to pre-WI HR, average post-WI HR decreased 4.3% lower (p<0.001), but increased overall by 8.2% over the course of repeated WI (p<0.001). Total peripheral resistance increased by an average of 13.1% following WI (p = 0.003). Thus, peripheral endothelial function increases after two days of WI, and PAT-derived measures of arterial stiffness increase transiently post-WI. Additionally, BP and PAT-derived endothelial function diverge from their usual associations with arterial stiffness (i.e. augmentation index) in the context of WI.
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Affiliation(s)
- Erin E. Simmons
- Navy Experimental Diving Unit, Panama City, Florida, United States of America
| | | | - John P. Florian
- Navy Experimental Diving Unit, Panama City, Florida, United States of America
- * E-mail:
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12
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Huang JH, Lin YK, Hsieh MH, Chen SA, Chiu WC, Chen YJ. Modulation of Autonomic Nervous Activity in the Termination of Paroxysmal Atrial Fibrillation. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2017; 40:401-408. [PMID: 28181276 DOI: 10.1111/pace.13045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/23/2017] [Accepted: 01/30/2017] [Indexed: 01/22/2023]
Abstract
BACKGROUND Autonomic nervous activity plays a critical role in the genesis of paroxysmal atrial fibrillation (AF, PAF). However, the role of autonomic nervous activity on AF termination has not been elucidated. Heart rate variability (HRV) is widely used to evaluate autonomic nervous activity in humans. The purpose of this study was to assess whether autonomic nervous activity assessed by HRV contributes to AF termination. METHODS Electrocardiograms (ECGs) and HRV were studied in patients with termination of sustained (>30 s) PAF by 24-hour ambulatory Holter monitoring. The 20-minute interval after termination of AF was divided into four segments of 5 minutes each, and a frequency analysis was applied to each 5-minute segment. RESULTS In 52 AF episodes, the ultra-low-frequency power, very-low-frequency power, low-frequency power (LF), high-frequency power (HF), and total power significantly decreased with time after episodes of AF termination. The LF/HF (L/H) ratio, normalized LF (LFnu), and normalized HF (HFnu) significantly changed after AF termination. Eighteen (35%) episodes had decreased LFnu and increased HFnu (sympathetic withdrawal and vagal activation), which had slower average AF ventricular responses (92 ± 16 beats/min vs 105 ± 24 beats/min, P < 0.05) than the AF termination episodes (n = 34, 65%) with increased LFnu and decreased HFnu (sympathetic activation and vagal withdrawal). Moreover, older patients (aged >65 years) had a higher incidence (n = 27, 75%) of AF termination with increased LFnu and decreased HFnu than did younger patients (aged ≤65 years, n = 7, 44%, P < 0.05). CONCLUSION Autonomic changes critically regulate termination of PAF, which is modulated by aging.
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Affiliation(s)
- Jen-Hung Huang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ming-Hsiung Hsieh
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Shih-Ann Chen
- Division of Cardiology and Cardiovascular Research Center, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Wan-Chun Chiu
- School of Nutrition and Health Sciences, College of Nutrition, Taipei Medical University, Taipei, Taiwan
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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Florian JP, Chon KH, Faes L, Shykoff BE. Breathing 100% oxygen during water immersion improves postimmersion cardiovascular responses to orthostatic stress. Physiol Rep 2016; 4:4/23/e13031. [PMID: 28604343 PMCID: PMC5260089 DOI: 10.14814/phy2.13031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 10/15/2016] [Indexed: 12/01/2022] Open
Abstract
Physiological compensation to postural stress is weakened after long‐duration water immersion (WI), thus predisposing individuals to orthostatic intolerance. This study was conducted to compare hemodynamic responses to postural stress following exposure to WI alone (Air WI), hyperbaric oxygen alone in a hyperbaric chamber (O2HC), and WI combined with hyperbaric oxygen (O2WI), all at a depth of 1.35 ATA, and to determine whether hyperbaric oxygen is protective of orthostatic tolerance. Thirty‐two healthy men underwent up to 15 min of 70° head‐up tilt (HUT) testing before and after a single 6‐h resting exposure to Air WI (N = 10), O2 HC (N = 12), or O2WI (N = 10). Heart rate (HR), blood pressure (BP), cardiac output (Q), stroke volume (SV), forearm blood flow (FBF), and systemic and forearm vascular resistance (SVR and FVR) were measured. Although all subjects completed HUT before Air WI, three subjects reached presyncope after Air WI exposure at 10.4, 9.4, and 6.9 min. HUT time did not change after O2WI or O2HC exposures. Compared to preexposure responses, HR increased (+10 and +17%) and systolic BP (−13 and −8%), and SV (−16 and −23%) decreased during HUT after Air WI and O2WI, respectively. In contrast, HR and SV did not change, and systolic (+5%) and diastolic BP (+10%) increased after O2HC. Q decreased (−13 and −7%) and SVR increased (+12 and +20%) after O2WI and O2HC, respectively, whereas SVR decreased (−9%) after Air WI. Opposite patterns were evident following Air WI and O2HC for FBF (−26 and +52%) and FVR (+28 and −30%). Therefore, breathing hyperbaric oxygen during WI may enhance post‐WI cardiovascular compensatory responses to orthostatic stress.
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Affiliation(s)
| | - Ki H Chon
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut
| | - Luca Faes
- Bruno Kessler Foundation, Trento, Italy.,BIOtech, University of Trento, Trento, Italy
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Bond V, Curry BH, Kumar K, Pemminati S, Gorantla VR, Kadur K, Millis RM. Nonlinear Conte-Zbilut-Federici (CZF) Method of Computing LF/HF Ratio: A More Reliable Index of Changes in Heart Rate Variability. J Pharmacopuncture 2016; 19:207-212. [PMID: 27695629 PMCID: PMC5043084 DOI: 10.3831/kpi.2016.19.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Objectives: Acupuncture treatments are safe and effective for a wide variety of diseases involving autonomic dysregulation. Heart rate variability (HRV) is a noninvasive method for assessing sympathovagal balance. The low frequency/high frequency (LF/HF) spectral power ratio is an index of sympathovagal influence on heart rate and of cardiovascular health. This study tests the hypothesis that from rest to 30% to 50% of peak oxygen consumption, the nonlinear Conte-Zbilut-Federici (CZF) method of computing the LF/HF ratio is a more reliable index of changes in the HRV than linear methods are. Methods: The subjects of this study were 10 healthy young adults. Electrocardiogram RR intervals were measured during 6-minute periods of rest and aerobic exercise on a cycle ergometer at 30% and 50% of peak oxygen consumption (VO2peak). Results: The frequency domain CZF computations of the LF/HF ratio and the time domain computations of the standard deviation of normal-to-normal intervals (SDNN) decreased sequentially from rest to 30% VO2peak (P < 0.001) to 50% VO2peak (P < 0.05). The SDNN and the CZF computations of the LF/HF ratio were positively correlated (Pearson’s r = 0.75, P < 0.001). fast Fourier transform (FFT), autoregressive (AR) and Lomb periodogram computations of the LF/HF ratio increased only from rest to 50% VO2peak. Conclusion: Computations of the LF/HF ratio by using the nonlinear CZF method appear to be more sensitive to changes in physical activity than computations of the LF/HF ratio by using linear methods. Future studies should determine whether the CZF computation of the LF/HF ratio improves evaluations of pharmacopuncture and other treatment modalities.
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Affiliation(s)
- Vernon Bond
- Department of Recreation, Human Performance & Leisure Studies, and Exercise Science & Human Nutrition Laboratory, Howard University Cancer Center, Washington D.C., United States of America
| | - Bryan H Curry
- Division of Cardiology, Department of Medicine, Howard University College of Medicine & Howard University Hospital, Washington D.C., United States America
| | - Krishna Kumar
- Department of Pharmaceutical Sciences, College of Pharmacy, Howard University, Washington D.C., United States of America
| | - Sudhakar Pemminati
- Departments of Pharmacology, American University of Antigua College of Medicine and Manipal University, St. John's, Antigua and Barbuda
| | - Vasavi R Gorantla
- Behavioral Science & Neuroscience, American University of Antigua College of Medicine, St. John's, Antigua and Barbuda
| | - Kishan Kadur
- Medical Physiology, American University of Antigua College of Medicine, St. John's, Antigua and Barbuda
| | - Richard M Millis
- Medical Physiology, American University of Antigua College of Medicine, St. John's, Antigua and Barbuda
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15
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Svensson MK, Lindmark S, Wiklund U, Rask P, Karlsson M, Myrin J, Kullberg J, Johansson L, Eriksson JW. Alterations in heart rate variability during everyday life are linked to insulin resistance. A role of dominating sympathetic over parasympathetic nerve activity? Cardiovasc Diabetol 2016; 15:91. [PMID: 27352833 PMCID: PMC4924321 DOI: 10.1186/s12933-016-0411-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/14/2016] [Indexed: 12/31/2022] Open
Abstract
Aims To evaluate the role of the autonomic nervous system (ANS) in the development of insulin resistance (IR) and assess the relationship between IR and activity of ANS using power spectrum analysis of heart rate variability (HRV). Subjects and methods Twenty-three healthy first-degree relatives of patients with type 2 diabetes (R) and 24 control subjects without family history of diabetes (C) group-matched for age, BMI and sex were included. Insulin sensitivity (M value) was assessed by hyperinsulinemic (56 mU/m2/min) euglycemic clamp. Activity of the ANS was assessed using power spectrum analysis of HRV in long-term recordings, i.e., 24-h ECG monitoring, and in short-term recordings during manoeuvres activating the ANS. Computed tomography was performed to estimate the amount and distribution of abdominal adipose tissue. Results Insulin sensitivity (M value, mg/kg lbm/min) did not differ significantly between the R and C groups. Total spectral power (Ptot) and very low-frequency (PVLF) power was lower in R than C during 24 h ECG-recordings (p = 0.02 and p = 0.03). The best fit multiple variable linear regression model (r2 = 0.37, p < 0.001 for model) indicated that body composition (BMI) and long-term low to high frequency (LF/HF) power ratio (std β = −0.46, p = 0.001 and std β = −0.28, p = 0.003, respectively) were significantly and independently associated with the M value. Conclusion Altered heart rate variability, assessed by power spectrum analysis, during everyday life is linked to insulin resistance. The data suggest that an increased ratio of sympathetic to parasympathetic nerve activity, occurring via both inherited and acquired mechanisms, could potentially contribute to the development of type 2 diabetes. Electronic supplementary material The online version of this article (doi:10.1186/s12933-016-0411-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maria K Svensson
- Department of Medical Sciences, Uppsala University Hospital, 751 85, Uppsala, Sweden.
| | - Stina Lindmark
- Department of Medicine, Umeå University Hospital, Umeå, Sweden
| | - Urban Wiklund
- Department of Biomedical Engineering & Informatics, Umeå University Hospital, Umeå, Sweden
| | - Peter Rask
- Department of Clinical Physiology, Örebro University Hospital, Örebro, Sweden
| | - Marcus Karlsson
- Department of Biomedical Engineering & Informatics, Umeå University Hospital, Umeå, Sweden
| | - Jan Myrin
- Department of Clinical Physiology, Örebro University Hospital, Örebro, Sweden
| | - Joel Kullberg
- Department of Radiology, Uppsala University Hospital, Uppsala, Sweden
| | - Lars Johansson
- Department of Radiology, Uppsala University Hospital, Uppsala, Sweden
| | - Jan W Eriksson
- Department of Medical Sciences, Uppsala University Hospital, 751 85, Uppsala, Sweden
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Soliński M, Gierałtowski J, Żebrowski J. Modeling heart rate variability including the effect of sleep stages. CHAOS (WOODBURY, N.Y.) 2016; 26:023101. [PMID: 26931582 DOI: 10.1063/1.4940762] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We propose a model for heart rate variability (HRV) of a healthy individual during sleep with the assumption that the heart rate variability is predominantly a random process. Autonomic nervous system activity has different properties during different sleep stages, and this affects many physiological systems including the cardiovascular system. Different properties of HRV can be observed during each particular sleep stage. We believe that taking into account the sleep architecture is crucial for modeling the human nighttime HRV. The stochastic model of HRV introduced by Kantelhardt et al. was used as the initial starting point. We studied the statistical properties of sleep in healthy adults, analyzing 30 polysomnographic recordings, which provided realistic information about sleep architecture. Next, we generated synthetic hypnograms and included them in the modeling of nighttime RR interval series. The results of standard HRV linear analysis and of nonlinear analysis (Shannon entropy, Poincaré plots, and multiscale multifractal analysis) show that-in comparison with real data-the HRV signals obtained from our model have very similar properties, in particular including the multifractal characteristics at different time scales. The model described in this paper is discussed in the context of normal sleep. However, its construction is such that it should allow to model heart rate variability in sleep disorders. This possibility is briefly discussed.
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Affiliation(s)
- Mateusz Soliński
- Faculty of Physics, Warsaw University of Technology, Warsaw 00-662, Poland
| | - Jan Gierałtowski
- Faculty of Physics, Warsaw University of Technology, Warsaw 00-662, Poland
| | - Jan Żebrowski
- Faculty of Physics, Warsaw University of Technology, Warsaw 00-662, Poland
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Kim K, Lee S, Kim JH. Diminished autonomic neurocardiac function in patients with generalized anxiety disorder. Neuropsychiatr Dis Treat 2016; 12:3111-3118. [PMID: 27994467 PMCID: PMC5153278 DOI: 10.2147/ndt.s121533] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Generalized anxiety disorder (GAD) is a chronic and highly prevalent disorder that is characterized by a number of autonomic nervous system symptoms. The purpose of this study was to investigate the linear and nonlinear complexity measures of heart rate variability (HRV), measuring autonomic regulation, and to evaluate the relationship between HRV parameters and the severity of anxiety, in medication-free patients with GAD. METHODS Assessments of linear and nonlinear complexity measures of HRV were performed in 42 medication-free patients with GAD and 50 healthy control subjects. In addition, the severity of anxiety symptoms was assessed using the State-Trait Anxiety Inventory and Beck Anxiety Inventory. The values of the HRV measures of the groups were compared, and the correlations between the HRV measures and the severity of anxiety symptoms were assessed. RESULTS The GAD group showed significantly lower standard deviation of RR intervals and the square root of the mean squared differences of successive normal sinus intervals values compared to the control group (P<0.01). The approximate entropy value, which is a nonlinear complexity indicator, was also significantly lower in the patient group than in the control group (P<0.01). In correlation analysis, there were no significant correlations between HRV parameters and the severity of anxiety symptoms. CONCLUSION The present study indicates that GAD is significantly associated with reduced HRV, suggesting that autonomic neurocardiac integrity is substantially impaired in patients with GAD. Future prospective studies are required to investigate the effects of pharmacological or non-pharmacological treatment on neuroautonomic modulation in patients with GAD.
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Affiliation(s)
| | - Seul Lee
- Department of Psychiatry, Gil Medical Center, Gachon University School of Medicine, Gachon University
| | - Jong-Hoon Kim
- Gachon University School of Medicine; Department of Psychiatry, Gil Medical Center, Gachon University School of Medicine, Gachon University; Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
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18
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The effects of cold water immersion with different dosages (duration and temperature variations) on heart rate variability post-exercise recovery: A randomized controlled trial. J Sci Med Sport 2015; 19:676-81. [PMID: 26614422 DOI: 10.1016/j.jsams.2015.10.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 09/21/2015] [Accepted: 10/07/2015] [Indexed: 11/22/2022]
Abstract
OBJECTIVES The aim of the present study was to investigate the effects of cold water immersion during post-exercise recovery, with different durations and temperatures, on heart rate variability indices. DESIGN Hundred participants performed a protocol of jumps and a Wingate test, and immediately afterwards were immersed in cold water, according to the characteristics of each group (CG: control; G1: 5' at 9±1°C; G2: 5' at 14±1°C; G3: 15' at 9±1°C; G4: 15' at 14±1°C). METHODS Analyses were performed at baseline, during the CWI recuperative technique (TRec) and 20, 30, 40, 50 and 60min post-exercise. The average HRV indices of all RR-intervals in each analysis period (MeanRR), standard deviation of normal RR-intervals (SDNN), square root of the mean of the sum of the squares of differences between adjacent RR-intervals (RMSSD), spectral components of very low frequency (VLF), low frequency (LF) and high frequency (HF), scatter of points perpendicular to the line of identity of the Poincaré Plot (SD1) and scatter points along the line of identity (SD2) were assessed. RESULTS Mean RR, VLF and LF presented an anticipated return to baseline values at all the intervention groups, but the same was observed for SDNN and SD2 only in the immersion for 15min at 14°C group (G4). In addition, G4 presented higher values when compared to CG. CONCLUSIONS These findings demonstrate that if the purpose of the recovery process is restoration of cardiac autonomic modulation, the technique is recommended, specifically for 15min at 14°C.
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Machado C, Estevez M, Perez-Nellar J, Schiavi A. Residual vasomotor activity assessed by heart rate variability in a brain-dead case. BMJ Case Rep 2015; 2015:bcr-2014-205677. [PMID: 25833905 DOI: 10.1136/bcr-2014-205677] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
A patient assessed by heart rate variability (HRV) methodology, beginning just after the completion of brain death (BD) diagnosis, showed remaining very low frequency (VLF) waves for approximately 10 min. A time-varying spectral analysis showed that during the first 550 s, a significant power spectral density remained in the high-frequency (HF), low-frequency (LF) and VLF bands. From 550 to 675 s, the HF oscillations totally vanished, and a marked progressive decay of the LF and VLF power density occurred. After 700 s the VLF undulations stopped and remaining small amplitude oscillations at 0.2 Hz coincided with the ventilator frequency. The VLF oscillations recorded in our case might be related to residual sympathetic vasomotor activity that progressively disappeared due to the extension of necrosis affecting the nervous centres of the lower part of the medulla and the first 2-3 cervical spine segments.
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Affiliation(s)
- Calixto Machado
- Department of Clinical Neurophysiology, Institute of Neurology and Neurosugery, Havana, Cuba
| | | | | | - Adam Schiavi
- Anesthesiology and Critical Care Medicine, Neurosciences Critical Care Division, Johns Hopkins Hospital, Baltimore, Maryland, USA
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Rodríguez-Liñares L, Lado MJ, Vila XA, Méndez AJ, Cuesta P. gHRV: Heart rate variability analysis made easy. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2014; 116:26-38. [PMID: 24854108 DOI: 10.1016/j.cmpb.2014.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 04/03/2014] [Accepted: 04/15/2014] [Indexed: 05/20/2023]
Abstract
In this paper, the gHRV software tool is presented. It is a simple, free and portable tool developed in python for analysing heart rate variability. It includes a graphical user interface and it can import files in multiple formats, analyse time intervals in the signal, test statistical significance and export the results. This paper also contains, as an example of use, a clinical analysis performed with the gHRV tool, namely to determine whether the heart rate variability indexes change across different stages of sleep. Results from tests completed by researchers who have tried gHRV are also explained: in general the application was positively valued and results reflect a high level of satisfaction. gHRV is in continuous development and new versions will include suggestions made by testers.
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Affiliation(s)
| | - M J Lado
- Department of Computer Science, ESEI, University of Vigo, Spain(1).
| | - X A Vila
- Department of Computer Science, ESEI, University of Vigo, Spain(1).
| | - A J Méndez
- Department of Computer Science, ESEI, University of Vigo, Spain(1).
| | - P Cuesta
- Department of Computer Science, ESEI, University of Vigo, Spain(1).
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21
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Florian JP, Simmons EE, Chon KH, Faes L, Shykoff BE. Cardiovascular and autonomic responses to physiological stressors before and after six hours of water immersion. J Appl Physiol (1985) 2013; 115:1275-89. [PMID: 23950166 DOI: 10.1152/japplphysiol.00466.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The physiological responses to water immersion (WI) are known; however, the responses to stress following WI are poorly characterized. Ten healthy men were exposed to three physiological stressors before and after a 6-h resting WI (32-33°C): 1) a 2-min cold pressor test, 2) a static handgrip test to fatigue at 40% of maximum strength followed by postexercise muscle ischemia in the exercising forearm, and 3) a 15-min 70° head-up-tilt (HUT) test. Heart rate (HR), systolic and diastolic blood pressure (SBP and DBP), cardiac output (Q), limb blood flow (BF), stroke volume (SV), systemic and calf or forearm vascular resistance (SVR and CVR or FVR), baroreflex sensitivity (BRS), and HR variability (HRV) frequency-domain variables [low-frequency (LF), high-frequency (HF), and normalized (n)] were measured. Cold pressor test showed lower HR, SBP, SV, Q, calf BF, LFnHRV, and LF/HFHRV and higher CVR and HFnHRV after than before WI (P < 0.05). Handgrip test showed no effect of WI on maximum strength and endurance and lower HR, SBP, SV, Q, and calf BF and higher SVR and CVR after than before WI (P < 0.05). During postexercise muscle ischemia, HFnHRV increased from baseline after WI only, and LFnHRV was lower after than before WI (P < 0.05). HUT test showed lower SBP, DBP, SV, forearm BF, and BRS and higher HR, FVR, LF/HFHRV, and LFnHRV after than before WI (P < 0.05). The changes suggest differential activation/depression during cold pressor and handgrip (reduced sympathetic/elevated parasympathetic) and HUT (elevated sympathetic/reduced parasympathetic) following 6 h of WI.
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Delgado E, Marques-Neves C, Rocha I, Sales-Luís J, Silva-Carvalho L. Myogenic oscillations in rabbit ocular vasculature are very low frequency. Ophthalmic Res 2013; 50:123-8. [PMID: 23899812 DOI: 10.1159/000351629] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 03/03/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS In a previously described model of isolated rabbit eye, we detected myogenic intrinsic vascular tone of unknown origin in the ophthalmic artery. In order to better understand the origin of these low frequency oscillations, we analyzed their spectral characteristics using fast Fourier. METHODS Hybrid New Zealand rabbits of either sex (n = 24) were used; they were divided into 2 groups according to age. The spectral characteristics of the myogenic behaviour of the rabbit external ophthalmic artery were analyzed using the fast Fourier algorithm. RESULTS The frequency of the oscillations of the myogenic activity seen in the rabbit external ophthalmic artery varied between 0.033 and 0.066 Hz (mean 0.045 ± 0.012 Hz), all in the region of very low frequency (VLF) oscillations (VLF <0.07 Hz for the rabbit). The frequency of spontaneous oscillations was higher in younger animals. CONCLUSION Fast Fourier analysis proved to be an adequate mathematical tool to analyze the myogenic tone oscillations, which were all in the range of VLF in the model we used. These results indicate that myogenic vascular function of ocular blood flow is composed of VLF oscillations, and they provide a new explanation for the origin of VLF in arterial spectra. They also suggest that the ocular local myogenic vascular function observed is more efficient in younger animals.
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Affiliation(s)
- E Delgado
- Departamento de Clínica, Centro de Investigação Interdisciplinar em Sanidade Animal, Faculty of Veterinary Medicine, Lisbon Technical University, Lisbon, Portugal.
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Mann MC, Exner DV, Hemmelgarn BR, Sola DY, Turin TC, Ellis L, Ahmed SB. Vitamin D levels are associated with cardiac autonomic activity in healthy humans. Nutrients 2013; 5:2114-27. [PMID: 23752493 PMCID: PMC3725496 DOI: 10.3390/nu5062114] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/29/2013] [Accepted: 06/03/2013] [Indexed: 12/19/2022] Open
Abstract
Vitamin D deficiency (≤50nmol/L 25-hydroxy vitamin D) is a cardiovascular (CV) risk factor that affects approximately one billion people worldwide, particularly those affected by chronic kidney disease (CKD). Individuals with CKD demonstrate abnormal cardiac autonomic nervous system activity, which has been linked to the significant rates of CV-related mortality in this population. Whether vitamin D deficiency has a direct association with regulation of cardiac autonomic activity has never been explored in humans. Methods: Thirty-four (34) healthy, normotensive subjects were studied and categorized based on 25-hydroxy vitamin D deficiency (deficient vs. non-deficient, n = 7 vs. 27), as well as 1,25-dihydroxy vitamin D levels (above vs. below 25th percentile, n = 8 vs. 26). Power spectral analysis of electrocardiogram recordings provided measures of cardiac autonomic activity across low frequency (LF) and high frequency (HF, representative of vagal contribution) bands, representative of the sympathetic and vagal limbs of the autonomic nervous system when transformed to normalized units (nu), respectively, as well as overall cardiosympathovagal balance (LF:HF) during graded angiotensin II (AngII) challenge (3 ng/kg/min × 30 min, 6 ng/kg/min × 30 min). Results: At baseline, significant suppression of sympathovagal balance was observed in the 25-hydroxy vitamin D-deficient participants (LF:HF, p = 0.02 vs. non-deficient), although no other differences were observed throughout AngII challenge. Participants in the lowest 1,25-dihydroxy VD quartile experienced significant withdrawal of inhibitory vagal control, as well as altered overall sympathovagal balance throughout AngII challenge (HF, mean difference = −6.98 ± 3 nu, p = 0.05; LF:HF, mean difference = 0.34 ± 0.1, p = 0.043 vs. above 25th percentile). Conclusions: Vitamin D deficiency is associated with suppression of resting cardiac autonomic activity, while low 1,25-dihydroxy vitamin D levels are associated with unfavourable cardiac autonomic activity during an acute AngII stressor, offering a potential pathophysiological mechanism that may be acting to elevate CV risk in in populations with low vitamin D status.
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Affiliation(s)
- Michelle C. Mann
- University of Calgary, 1403 29th St. NW, Calgary, AB T2N 2T9, Canada; E-Mails: (M.C.M.); (B.R.H.)
| | - Derek V. Exner
- Libin Cardiovascular Institute of Alberta, 3330 Hospital Dr. NW, Calgary, AB T2N 2T9, Canada; E-Mails: exner@ucalgary (D.V.E.); (D.Y.S.); (T.C.T.); (L.E.)
| | - Brenda R. Hemmelgarn
- University of Calgary, 1403 29th St. NW, Calgary, AB T2N 2T9, Canada; E-Mails: (M.C.M.); (B.R.H.)
| | - Darlene Y. Sola
- Libin Cardiovascular Institute of Alberta, 3330 Hospital Dr. NW, Calgary, AB T2N 2T9, Canada; E-Mails: exner@ucalgary (D.V.E.); (D.Y.S.); (T.C.T.); (L.E.)
| | - Tanvir C. Turin
- Libin Cardiovascular Institute of Alberta, 3330 Hospital Dr. NW, Calgary, AB T2N 2T9, Canada; E-Mails: exner@ucalgary (D.V.E.); (D.Y.S.); (T.C.T.); (L.E.)
| | - Linda Ellis
- Libin Cardiovascular Institute of Alberta, 3330 Hospital Dr. NW, Calgary, AB T2N 2T9, Canada; E-Mails: exner@ucalgary (D.V.E.); (D.Y.S.); (T.C.T.); (L.E.)
| | - Sofia B. Ahmed
- University of Calgary, 1403 29th St. NW, Calgary, AB T2N 2T9, Canada; E-Mails: (M.C.M.); (B.R.H.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-403-944-2745; Fax: +1-403-944-2876
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Hernando D, Alcaine A, Laguna P, Pueyo E, Bailon R. Very low frequency modulation in QRS slopes and its relation with respiration and heart rate variability during hemodialysis. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:5365-5368. [PMID: 24110948 DOI: 10.1109/embc.2013.6610761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this work, we study the very low frequency (VLF) modulation (range 0.01-0.03 Hz) in QRS slopes, heart rate variability (HRV) and ECG-derived respiration in hemodialysis patients. First, the relation between QRS slopes and HRV in the VLF band is measured using ordinary coherence. Then, partial coherence is used to measure the former relationship once the effect related to respiration is removed. Ordinary coherence values above a statistical threshold revealed linear relationship between VLF modulation in QRS slopes and HRV in about 10% of analyzed segments, with mean ± SD values of 0.79 ± 0.07 for upward slope and 0.77 ± 0.06 for downward slope. For these segments, partial coherence values drop below the threshold for 64% of the cases for upward slope and 76% for downward slope, suggesting that the origin of the VLF modulation in QRS slopes is mainly driven by respiration or linearly related to it. In the rest of the cases, partial coherence values dropped with respect to ordinary coherence from 0.89 to 0.77 for upward slope and from 0.86 to 0.75 for downward slope, suggesting that other ANS effects non-linearly related to respiration also contribute to the VLF modulation in QRS slopes.
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Kooman JP, Usvyat L, van der Sande FM, Thijssen S, Levin N, Leunissen KM, Kotanko P. 'Time and time again': oscillatory and longitudinal time patterns in dialysis patients. Kidney Blood Press Res 2012; 35:534-48. [PMID: 22890114 DOI: 10.1159/000340022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Oscillatory and longitudinal time patterns play a major role in human physiology. In chronic hemodialysis patients, abnormalities in both time patterns have been observed, while time patterns can also influence the response of patients to the treatment. Abnormal oscillatory patterns have been observed for ultradian rhythms (cycle time <20 h), such as an impaired heart rate variability and circadian rhythms, as reflected by reduced day-night blood pressure differences. Conversely, the circadian rhythm of body temperature may influence the hemodynamic tolerance to the dialysis treatment. With regard to infradian (cycle time >28 h) rhythms, large seasonal differences in mortality, but also in blood pressure and interdialytic weight gain, have been observed in dialysis patients. The most important longitudinal pattern is the general reduction of life span in dialysis patients. One explanation of this phenomenon relates to the concept of accelerated aging in dialysis patients, for which there are various supportive arguments. From a phenomenological point of view, this concept translates into the high prevalence of frailty, even in young dialysis patients. A multidimensional approach appears necessary to adequately address this problem. In this review, the relevance of disturbed time patterns in dialysis patients is discussed. The changes may reflect an impairment or reduction in homeostatic/homeodynamic control in dialysis patients and also may have important prognostic and therapeutic implications.
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Affiliation(s)
- Jeroen P Kooman
- University Hospital Maastricht, Maastricht, The Netherlands.
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Santarcangelo EL, Paoletti G, Balocchi R, Scattina E, Ghelarducci B, Varanini M. Watching neutral and threatening movies: subjective experience and autonomic responses in subjects with different hypnotizability levels. Int J Psychophysiol 2012; 84:59-64. [PMID: 22285555 DOI: 10.1016/j.ijpsycho.2012.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 12/26/2011] [Accepted: 01/10/2012] [Indexed: 11/26/2022]
Abstract
Subjects with high hypnotizability scores (Highs) have been considered more prone to experience negative affect and more vulnerable to its autonomic effects with respect to low hypnotizable individuals (Lows). The aim of the study was to analyze the subjective experience, tonic skin conductance (SC), respiratory frequency (RF), heart rate (HR) and heart rate variability (HRV) of healthy Highs and Lows during a long-lasting, emotionally neutral task (Session R, 46 subjects) and a moderately threatening one (Session T, 35 subjects). At the end of the relaxing Session R, all participants reported an increased relaxation. At the end of the threatening Session T, only 20 subjects reported a decreased relaxation (effective T: eT subsample). Highs and Lows of this subsample reported a similarly reduced relaxation and showed a similarly increased skin conductance. HR and HRV did not differ between the two sessions and between Highs and Lows. Among the subjects not reporting decreased relaxation at the end of Session T (ineffective T: iT subsample, n=15), relaxation was deeper and associated with lower skin conductance in Highs, although HR and HRV did not differ between Highs and Lows. All together, the results do not support the hypothesis of higher proneness of Highs to experience negative affect and to exhibit the autonomic correlates of negative emotion.
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