Use of opposing reflex stimuli and heart rate variability to examine the effects of lipophilic and hydrophilic β-blockers on human cardiac vagal control

1999 ◽  
Vol 97 (5) ◽  
pp. 585-593 ◽  
Author(s):  
Julian C. VAILE ◽  
Janine FLETCHER ◽  
Muzahim AL-ANI ◽  
Hamish F. ROSS ◽  
William A. LITTLER ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Animal Studies ◽  
Vagal Activity ◽  
Blocker Therapy ◽  
Healthy Humans ◽  
Trigeminal Stimulation ◽  
Β Blocker ◽  
Β Blockers

Evidence from animal studies suggests that β-blockers can act within the central nervous system to increase cardiac vagal motoneuron activity. We have attempted to determine whether such an effect is evident in healthy humans, by examining the effects of lipophilic and hydrophilic agents on heart rate variability and cardiac vagal reflexes. A total of 20 healthy volunteers took part in the study. Autonomic studies were performed after 72 h of treatment with placebo, atenolol or metoprolol in a blinded cross-over design. ECG recordings were taken at rest and during mental and orthostatic stress. Heart rate variability was measured in the time and frequency domains. The effects on heart rate of two opposing cardiac vagal reflexes were examined. Trigeminal stimulation causing vagal stimulation, and isometric forearm muscle contraction (‘muscle heart reflex’) causing vagal inhibition, were performed alone and simultaneously. At rest, during mental stress and during trigeminal stimulation, β-blocker therapy was associated with significantly increased high-frequency beat-to-beat heart rate variability when compared with placebo. There were no significant differences in effects on heart rate or heart rate variability between atenolol and metoprolol. Analysis of the muscle heart reflex, alone and with simultaneous trigeminal stimulation, showed that the magnitude of the R–R interval response was significantly greater after β-blocker therapy compared with placebo, but the effects of atenolol and metoprolol were equivalent. β-Blocker therapy increased cardiac vagal activity, as shown by measures of high-frequency heart rate variability and reflex studies. Lipophilic and hydrophilic β-blockers appeared to be equally efficacious in increasing the cardiac vagal modulation of heart rate.

scholarly journals Resting vagal activity in schizophrenia: Meta-analysis of heart rate variability as a potential endophenotype

2016 ◽  
Vol 208 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Annika Clamor ◽  
Tania M. Lincoln ◽  
Julian F. Thayer ◽  
Julian Koenig
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Meta Analysis ◽  
Random Effect ◽  
Vagal Tone ◽  
Sensitivity Analyses ◽  
Psychotic Symptoms ◽  
Vagal Activity ◽  
Healthy Controls

BackgroundCardiac vagal tone, indexed by heart rate variability (HRV), is a proxy for the functional integrity of feedback mechanisms integrating central and peripheral physiology.AimsTo quantify differences in HRV in individuals with schizophrenia compared with healthy controls.MethodDatabases were systematically searched for studies eligible for inclusion. Random effect meta-analyses of standardised mean differences were calculated for vagal activity indicated by high-frequency HRV and the root mean square of successive R–R interval differences (RMSSD).ResultsThirty-four studies were included. Significant main effects were found for high-frequency HRV (P = 0.0008; Hedges' g =–0.98, 95% CI −1.56 to −0.41, k = 29) and RMSSD (P<0.0001; g =–0.91, 95% CI −1.19 to −0.62, k = 24), indicating lower vagal activity in individuals with schizophrenia than in healthy controls. Considerable heterogeneity was evident but effects were robust in subsequent sensitivity analyses.ConclusionsGiven the association between low HRV, threat processing, emotion regulation and executive functioning, reduced vagal tone may be an endophenotype for the development of psychotic symptoms.

scholarly journals Resting high frequency heart rate variability is not associated with the recognition of emotional facial expressions in healthy human adults

2016 ◽  
Author(s):  
Brice Beffara ◽  
Nicolas Vermeulen ◽  
Martial Mermillod
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Facial Expressions ◽  
High Frequency ◽  
Vagal Activity ◽  
Emotional Facial Expressions ◽  
Polyvagal Theory ◽  
Healthy Human ◽  
Integration Model ◽  
Human Adults

This study explores whether the myelinated vagal connection between the heart and the brain is involved in emotion recognition. The Polyvagal theory postulates that the activity of the myelinated vagus nerve underlies socio-emotional skills. It has been proposed that the perception of emotions could be one of this skills dependent on heart-brain interactions. However, this assumption was differently supported by diverging results suggesting that it could be related to confounded factors. In the current study, we recorded the resting state vagal activity (reflected by High Frequency Heart Rate Variability, HF-HRV) of 77 (68 suitable for analysis) healthy human adults and measured their ability to identify dynamic emotional facial expressions. Results show that HF-HRV is not related to the recognition of emotional facial expressions in healthy human adults. We discuss this result in the frameworks of the polyvagal theory and the neurovisceral integration model.

Heart Rate Variability Indexes in Dementia: A Systematic Review with a Quantitative Analysis

2017 ◽  
Vol 15 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Vanessa Pereira da Silva ◽  
Bruno Ribeiro Ramalho Oliveira ◽  
Roger Gomes Tavares Mello ◽  
Helena Moraes ◽  
Andrea Camaz Deslandes ◽  
...  
Keyword(s):  
Systematic Review ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Quantitative Analysis ◽  
Autonomic Dysfunction ◽  
Effect Size ◽  
High Frequency ◽  
Vagal Activity

Background: Decreased heart rate variability (HRV) indexes indicate low vagal activity and may be associated with development of dementia. The neurodegenerative process is associated with the cardiovascular autonomic control. Objective: The aim of this systematic review was to investigate the effect size (ES) magnitude of the HRV indexes in the evaluation of autonomic dysfunction in older persons with dementia. Methods: PubMed (Medline), Web of Science, Scopus, Scielo, Lilacs, and APA Psycnet were consulted. Complete original articles published in English or Portuguese, investigating the association between autonomic dysfunction and dementia, using the HRV indexes were included. Results: The search identified 97 potentially relevant articles. After screening the full text, eight articles were included in the qualitative analysis and six were included in the quantitative analysis. Almost all indexes showed a negative ES for all types of dementia and mild cognitive impairment. The most common frequency band of the power spectrum density function was the high frequency, which was reported by six studies. The meta-analysis of high frequency power in Alzheimer's disease group showed high heterogeneity and inconsistent results. Conclusion: The negative effect size suggests an autonomic dysfunction in all types of dementia as well as mild cognitive impairment. However, further analysis is necessary to support these results.

scholarly journals Heart rate variability in women with essential hypertension under exposure of regular moderate physical training

2019 ◽  
Vol 16 (4) ◽  
pp. 61-64 ◽  
Author(s):  
Yuriy N Smolyakov ◽  
Boris I Kuznik ◽  
Ekaterina S Guseva ◽  
Sergey O Davydov
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Essential Hypertension ◽  
High Frequency ◽  
Low Frequency ◽  
Total Power ◽  
Vagal Activity ◽  
Frequency Range ◽  
Pronounced Increase ◽  
Respiratory Movements

The task of the study was to elucidate the effect of moderate exercise on heart rate variability (HRV) in women who regularly take kinesitherapy courses. Materials and methods. Studies were conducted on 72 women with essential hypertension (EH), divided into 2 subgroups: first (EH-1) included 37 women suffering from stage II EH and under medical therapy, the second (EH-2) consisted of patients who underwent along with medication treatment, regular courses of kinesitherapy. To evaluate the characteristics of HRV, a photoplethysmography method was used. The following indicators were used: SDRR is the standard deviation of all cardiointervals, RMSSD is the square root of the average sum of squares of cardiointerval differences, LF - is the oscillation power in the low frequency range, due to the activity of the sympathetic section, HF - is the power in the high frequency range, associated with respiratory movements and caused by vagal activity, LF/HF - is the power ratio, reflecting sympathetic balance, CVI - nonlinear parasympathetic index, CSI - nonlinear sympathetic index. Results. It was established that the average heart rate in women of both groups is approximately the same, while all other indicators (with the exception of LF/HF and CSI) were significantly higher in patients EH-2 group. In patients EH-2 group, there is a significantly larger value of SDRR, RMSSD, LF, HF. In the frequency analysis, no increase in the total power of cardiointerval oscillations and autonomic balance (LF/HF) was detected. A pronounced increase in the nonlinear parasympathetic index (CVI) has been shown, while the sympathetic index (CSI) remained unchanged. Conclusion. Regular use of kinesitherapy courses helps to increase the tone of the parasympathetic division of the autonomic nervous system, which is significantly depressed in EH.

scholarly journals Direct measurement of vagal tone in rats does not show correlation to HRV

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joseph T. Marmerstein ◽  
Grant A. McCallum ◽  
Dominique M. Durand
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Neural Activity ◽  
Vagal Tone ◽  
Neural Recording ◽  
The Body ◽  
Autonomic Nerve ◽  
Vagal Activity ◽  
Recording Technology

AbstractThe vagus nerve is the largest autonomic nerve, innervating nearly every organ in the body. “Vagal tone” is a clinical measure believed to indicate overall levels of vagal activity, but is measured indirectly through the heart rate variability (HRV). Abnormal HRV has been associated with many severe conditions such as diabetes, heart failure, and hypertension. However, vagal tone has never been directly measured, leading to disagreements in its interpretation and influencing the effectiveness of vagal therapies. Using custom carbon nanotube yarn electrodes, we were able to chronically record neural activity from the left cervical vagus in both anesthetized and non-anesthetized rats. Here we show that tonic vagal activity does not correlate with common HRV metrics with or without anesthesia. Although we found that average vagal activity is increased during inspiration compared to expiration, this respiratory-linked signal was not correlated with HRV either. These results represent a clear advance in neural recording technology but also point to the need for a re-interpretation of the link between HRV and “vagal tone”.

scholarly journals Effect of Hypoglycemia on Heart Rate Variability in People with Type 1 Diabetes and Impaired Awareness of Hypoglycemia

2021 ◽  
pp. 193229682110074
Author(s):  
Mats Koeneman ◽  
Marleen Olde Bekkink ◽  
Lian van Meijel ◽  
Sebastian Bredie ◽  
Bastiaan de Galan
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Sympathetic Activity ◽  
Elevated Risk ◽  
Wilcoxon Rank Sum Test ◽  
Impaired Awareness ◽  
Induced Changes ◽  
Measurable Change

Background: People with impaired awareness of hypoglycemia (IAH) are at elevated risk of severe, potentially hazardous, hypoglycemia and would benefit from a device alerting to hypoglycemia. Heart rate variability (HRV) changes with hypoglycemia due to sympathetic activity. Since IAH is associated with suppressed sympathetic activity, we investigated whether hypoglycemia elicits a measurable change in HRV in patients with T1D and IAH. Method: Eligible participants underwent a modified hyperinsulinemic euglycemic hypoglycemic clamp (glucose nadir, 43.1 ± 0.90 mg/dl), while HRV was measured by a VitalConnect HealthPatch. Measurements of HRV included Root Mean Square of the Successive Differences (RMSSD) and low to high frequency (LF:HF) ratio. Wilcoxon rank-sum test was used for testing within-subject HRV changes. Results: We included 12 participants (8 female, mean age 57 ± 12 years, mean HbA1c 57 ± 5 mmol/mol (7.4 ± 0.4%)). Symptoms increased from 4.0 (1.5-7.0) at euglycemia to 7.5 (5.0-11.0) during hypoglycemia ( P = .003). In response to hypoglycemia, the LF:HF ratio and RMSSD increased when normalized for data obtained during euglycemia (both P < .01). The LF:HF ratio increased in 6 participants (50%) and declined in one other participant (8%). The RMSSD decreased in 3 (25%) and increased in 4 (33%) participants. In 2 patients, no change in HRV could be detected in response to hypoglycemia. Conclusions: This study reveals that hypoglycemia-induced changes in HRV are retained in the majority of people with T1D and IAH, and that these changes can be detected by a wearable device. Real-time HRV seems usable for detection of hypoglycemia in patients with IAH.

scholarly journals Effect of short-term exposure to particulate air pollution on heart rate variability in normal-weight and obese adults

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Luyi Li ◽  
Dayu Hu ◽  
Wenlou Zhang ◽  
Liyan Cui ◽  
Xu Jia ◽  
...  
Keyword(s):  
Heart Rate ◽  
Air Pollution ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Normal Weight ◽  
High Frequency Power ◽  
Short Term ◽  
Particulate Air Pollution ◽  
Short Term Exposure ◽  
Frequency Power

Abstract Background The adverse effects of particulate air pollution on heart rate variability (HRV) have been reported. However, it remains unclear whether they differ by the weight status as well as between wake and sleep. Methods A repeated-measure study was conducted in 97 young adults in Beijing, China, and they were classified by body mass index (BMI) as normal-weight (BMI, 18.5–24.0 kg/m2) and obese (BMI ≥ 28.0 kg/m2) groups. Personal exposures to fine particulate matter (PM2.5) and black carbon (BC) were measured with portable exposure monitors, and the ambient PM2.5/BC concentrations were obtained from the fixed monitoring sites near the subjects’ residences. HRV and heart rate (HR) were monitored by 24-h Holter electrocardiography. The study period was divided into waking and sleeping hours according to time-activity diaries. Linear mixed-effects models were used to investigate the effects of PM2.5/BC on HRV and HR in both groups during wake and sleep. Results The effects of short-term exposure to PM2.5/BC on HRV were more pronounced among obese participants. In the normal-weight group, the positive association between personal PM2.5/BC exposure and high-frequency power (HF) as well as the ratio of low-frequency power to high-frequency power (LF/HF) was observed during wakefulness. In the obese group, personal PM2.5/BC exposure was negatively associated with HF but positively associated with LF/HF during wakefulness, whereas it was negatively correlated to total power and standard deviation of all NN intervals (SDNN) during sleep. An interquartile range (IQR) increase in BC at 2-h moving average was associated with 37.64% (95% confidence interval [CI]: 25.03, 51.51%) increases in LF/HF during wakefulness and associated with 6.28% (95% CI: − 17.26, 6.15%) decreases in SDNN during sleep in obese individuals, and the interaction terms between BC and obesity in LF/HF and SDNN were both statistically significant (p <  0.05). The results also suggested that the effects of PM2.5/BC exposure on several HRV indices and HR differed in magnitude or direction between wake and sleep. Conclusions Short-term exposure to PM2.5/BC is associated with HRV and HR, especially in obese individuals. The circadian rhythm of HRV should be considered in future studies when HRV is applied. Graphical abstract

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