scholarly journals Cardiac Parasympathetic Withdrawal and Sympathetic Activity: Effect of Heat Exposure on Heart Rate Variability

2021 ◽  
Vol 18 (11) ◽  
pp. 5934
Author(s):  
Oriol Abellán-Aynés ◽  
Pedro Manonelles ◽  
Fernando Alacid
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Environmental Conditions ◽  
Sympathetic Activity ◽  
Heat Exposure ◽  
Repeated Measurements ◽  
Control Group ◽  
Poincaré Plot ◽  
Activity Effect ◽  
And Control

(1) Background: Research on heart rate variability has increased in recent years and the temperature has not been controlled in some studies assessing repeated measurements. This study aimed to analyze how heart rate variability may change based on environmental temperature during measurement depending on parasympathetic and sympathetic activity variations. (2) Methods: A total of 22 volunteers participated in this study divided into an experimental (n = 12) and control group (n = 10). Each participant was assessed randomly under two different environmental conditions for the experimental group (19 °C and 35 °C) and two identical environmental conditions for the control group (19 °C). During the procedure, heart rate variability measurements were carried out for 10 min. (3) Results: Significantly changes were observed for time and frequency domains as well as Poincaré plot variables after heat exposure (p < 0.05). These findings were not observed in the control group, whose conditions between measurements did not change. (4) Conclusions: The reduction of heart rate variability due to exposure to hot conditions appears to be produced mostly by a parasympathetic withdrawal rather than a sympathetic activation. Therefore, if consecutive measurements have to be carried out, these should always be done under the same temperature conditions.

scholarly journals Periodized Aerobic Interval Training Modifies Geometric Indices of Heart Rate Variability in Metabolic Syndrome

Medicina ◽  
2019 ◽  
Vol 55 (9) ◽  
pp. 532
Author(s):  
Laís Manata Vanzella ◽  
Denise Brugnoli Balbi Dagostinho ◽  
Maria Paula Ferreira de Figueiredo ◽  
Carlos Iván Mesa Castrillón ◽  
Jayme Netto Junior ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Standard Deviation ◽  
Interval Training ◽  
Training Group ◽  
Control Group ◽  
Autonomic Modulation ◽  
Poincaré Plot ◽  
Aerobic Interval Training

Background: Metabolic syndrome (MetS) influences the autonomic modulation, increasing the risk of cardiovascular events, which demands the identification of effective treatments for this population. Considering this, the study has the objective of evaluating the effects of periodized aerobic interval training (AIT) on geometrical methods of heart rate variability (HRV) on individuals with MetS. Methods: 52 individuals with MetS were considered for analysis. They were divided into two groups: aerobic interval training group (AITG; n = 26) and control group (CG; n = 26). The AITG performed 16 weeks of periodized AIT. For HRV analysis, the heart rate was recorded beat-by-beat at the beginning and the end of the AIT program and geometrical methods were used for analysis. Results: significant increase was observed for triangular index (RRtri, −1.25 ± 0.58 vs. 1.41 ± 0.57), standard deviation of distances from diagonal to points (SD1, −0.13 ± 1.52 vs. 4.34 ± 1.49), and standard deviation of distances from points to lines (SD2, −2.14 ± 3.59 vs. 11.23 ± 3.52) on AITG compared to CG. Significant differences were not observed for triangular interpolation of normal heartbeats interval histogram (TINN, −4.05 ± 17.38 vs. 25.52 ± 17.03) and SD1/SD2 ratio (0.03 ± 0.02 vs. 0.00 ± 0.02). Qualitative analysis of the Poincaré plot identified increase on dispersion of both short and long-term intervals between successive heartbeats (RR interval) on AITG after the AIT program. Conclusion: geometric indices of HRV suggest an increase in cardiac autonomic modulation in individuals with MetS after 16 weeks of periodized AIT.

scholarly journals Evaluation of the effects of aerobic exercise in the aqueous environment on heart rate variability by using Poincare plot nonlinear method

2020 ◽  
pp. 36-49
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Standard Deviation ◽  
Aerobic Exercise ◽  
Autonomic System ◽  
Control Group ◽  
Aqueous Environment ◽  
Time Intervals ◽  
Poincaré Plot ◽  
Adjacent Sequence

Background and Aim: Heart rate variability used as a non-invasive method to investigate the effect of aerobics exercise on the cardiac autonomic system. The aim of this study was the nonlinear analysis of the effect of aerobic exercise in the water on the cardiac autonomic system in academic young's males. Materials and Methods: A total of 28 young men were randomly assigned to two groups of control and aerobic exercise in water. In the pre-test period and after the training intervention, all parameters of heart rate variability were measured by examining heart rate sequences, In the pre-test period and after the training intervention, all parameters of heart rate variability were measured by examining heart rate sequences, and then the standard deviation of the recorded sequences was interpreted by using the Poincare plot method. Independent t-test and paired t-test were used to compare the differences in the research stages. Results: Regular participation in aerobic exercise in water caused a significant (45.1±9.2 vs. 34.1±12.3) and standard deviation of time intervals of heart rate sequences compared to their adjacent sequence compared to the control group (P=0.03). The longitudinal standard deviation of time intervals of heart rate sequences compared to the pre-test (P=0.04) had a significant increase (79.5±12.5 vs. 56.9±15.8 After transferring the absolute results to normal, the normal state of the standard deviation of time intervals of heart rate sequences compared to its adjacent sequence compared to the control group (P=0.03) had a significant increase (44.7±12.05 vs. 36.5±13.52). Also, the normal state of the longitudinal standard deviation of time intervals of heart rate sequences compared to the pre-test (P=0.02) increased significantly (76.4±15.29 vs. 61.3±9.32). Conclusion: Performing aerobic exercise in an aqueous environment can be used as a useful training method to improve the responsiveness of the cardiac autonomic system.

Heart Rate Variability during Chemical Thoracic Sympathectomy

1998 ◽  
Vol 89 (3) ◽  
pp. 666-670. ◽  
Author(s):  
Munetaka Hirose ◽  
Hiroto Imai ◽  
Misako Ohmori ◽  
Yasunori Matsumoto ◽  
Fumimasa Amaya ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Scatter Diagram ◽  
Poincaré Plot ◽  
Cardiac Sympathetic Activity ◽  
Concomitant Change ◽  
Thoracic Sympathectomy ◽  
Diagonal Line ◽  
Severe Bradycardia

Background Chemical thoracic sympathectomy (CTS) resulted in profound bradycardia in a patient with severe post-therapeutic neuralgia. To clarify the cause of this bradycardia, the authors evaluated heart rate variability using a Poincaré plot, which is a scatter diagram of the current R-R interval plotted against the R-R interval immediately preceding it, in this patient and in others scheduled for CTS or mandibular block (MB). Methods Twenty-three patients were scheduled for CTS (n = 13, CTS group) and for MB (n = 10, MB group). Heart rate and the SD of the R-R interval variabilities spreading along the x axis (SDRR) and perpendicularly along the diagonal line of the Poincaré plot (SDdeltaRR) were evaluated before, just after, and 1 h after the block. Results Neither group had significant changes in heart rate. The MB group showed no significant change in the SD(RR):SDdeltaRR ratio. In the CTS group, however, the SD(RR):SDdeltaRR ratio decreased significantly from 1.72+/-0.20 to 1.23+/-0.11 just after CTS. The previous patient, who had a high SD(RR):SDdeltaRR ratio of 3.45 before CTS, exhibited severe bradycardia (22 beats/min). Conclusions The SD(RR):SDdeltaRR ratio decreased after CTS without any significant concomitant change in heart rate. The decrease in the SD(RR):SDdeltaRR. ratio indicates a reduction of cardiac sympathetic activity. However, CTS in patients having high SD(RR):SDdeltaRR ratios can result in profound bradycardia.

scholarly journals Heart rate variability change during a stressful cognitive task in individuals with anxiety and control participants

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Judith Held ◽  
Andreea Vîslă ◽  
Christine Wolfer ◽  
Nadine Messerli-Bürgy ◽  
Christoph Flückiger
Keyword(s):  
Heart Rate ◽  
Working Memory ◽  
Heart Rate Variability ◽  
Cognitive Task ◽  
Memory Task ◽  
Patient Characteristics ◽  
Recovery Phase ◽  
Control Group ◽  
Anxious Group ◽  
And Control

Abstract Background Individuals suffering from an anxiety disorder are characterized by chronically low heart rate variability (HRV) compared to healthy individuals during resting state conditions. However, when examining HRV and HR in response to a stressor, mixed results have been obtained when comparing anxious and non-anxious groups. Methods The primary aim of the present study was to investigate HRV and HR responding in 26 clinically anxious and 14 control individuals before, during and after a stressful working memory task. Results Results indicate no between-group differences in HRV and HR at baseline. When starting the working memory task, the control group decreased significantly in HRV and the anxious group did not differ substantially in their change pattern from baseline to the start of the stressor. Finally, during the recovery phase of the working memory task, the clinically anxious and control individuals did not differ in their HFV or HR response compared to baseline. Conclusions From a clinical perspective, the results suggest that screening for the presence of anxiety disorders may help to identify patients with impaired HRV and HR functioning and to intervene on these important patient characteristics early in the treatment process.

Immediate effects of the practise of Sheethali pranayama on heart rate and blood pressure parameters in healthy volunteers

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rohini P. ◽  
Roopa S. ◽  
Padmavathi R. ◽  
Maheshkumar K.
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Healthy Volunteers ◽  
Sympathetic Activity ◽  
Pressure Pulse ◽  
Control Group ◽  
Normal Breathing ◽  
And Control

Abstract Objectives Sheetali pranayama, a cooling pranayama is best known for its calming and relaxing nature, widely used for many conditions like depression, anxiety and hypertension. The aim of the study was to evaluate the immediate effect of the practice of Sheetali pranayama on heart rate and blood pressure parameters in healthy volunteers. Methods Apparently, 60 healthy volunteers were involved, from both sexes. They were split into pranayama (n=30) and control (n=30) groups at random. Sheetali pranayama was performed for 5 min (5 cycles) in the pranayama group and normal breathing (12–16 breaths/min) was permitted in the control group. Heart rate (HR) and blood pressure (BP) were recorded with RMS polyrite in the supine position after 5 min of rest. Results The HR in the pranayama group significantly decreased (p=0.04). Systolic (SBP) and diastolic blood (DBP) pressure, pulse pressure (PP) and mean arterial pressure (MAP) decreased significantly (p<0.05) relative to control after pranayama practice. Pre-Post inter-group results has also shown that the pranayama group has substantially decreased HR and BP indices. Conclusions Present study shows that the practice of Sheetlai pranayama creates a relaxed state, and parasympathetic activity overrides sympathetic activity in this state. It indicates that in healthy volunteers, pranayama strengthens the resting cardiovascular parameters.

Nonlinear Analysis of Heart Rate Variability During Qi Therapy (External Qigong)

2005 ◽  
Vol 33 (04) ◽  
pp. 579-588 ◽  
Author(s):  
Myeong Soo Lee ◽  
Young Hoon Rim ◽  
Dong-Myong Jeong ◽  
Mo Kyung Kim ◽  
Min Cheol Joo ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Nonlinear Analysis ◽  
Control Group ◽  
Placebo Control ◽  
Poincaré Plot ◽  
Cardiac Autonomic Nervous System ◽  
Autonomic Nervous

Heart rate variability (HRV) was compared in 30 subjects receiving external Qi therapy (EQT) or placebo control therapy, in a crossover design experiment. Subjects who received the EQT reported more pleasant and calm emotions than did the placebo group. Qi therapy reduced the heart rate and increased HRV as indicated by a reduced low frequency/high frequency power ratio of HRV. With nonlinear analysis, the Poincaré plot index of HRV and approximate entropy was greater in the EQT group than in the control group. These findings suggest that EQT stabilizes the sympathovagal function and cardiac autonomic nervous system by inducing more positive emotions than the placebo therapy. In conclusion, EQT may act by stabilizing both the autonomic nervous system and the emotional state.

Fish Consumption and Heart Rate Variability

2010 ◽  
Vol 24 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Anita L. Hansen ◽  
Lisbeth Dahl ◽  
Lene Bakke ◽  
Livar Frøyland ◽  
Julian F. Thayer
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Intervention Group ◽  
Biological Marker ◽  
Good Health ◽  
Health Improvement ◽  
Control Group ◽  
Omega 3 ◽  
And Control ◽  
The Impact

The present study investigates the impact of seafood intake on biological markers in blood such as the marine very long-chain polyunsaturated omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), 25-hydroxyvitamin D (25(OH)D), in addition to heart rate variability (HRV), which is an important biological marker of good health, both physical and mental. A total of 53 male inmates from a Norwegian prison were randomly assigned to intervention and control groups, although attrition reduced some comparisons at the end of the study to 13 (intervention group (n = 6) and control group (n = 7). The intervention group received seafood (mainly fatty fish, > 8% fat) for dinner three times per week for a period of 6 months. Both groups were requested to eat their usual diet provided by the prison. Blood samples were collected and HRV (high frequency (HF) and low frequency (LF) power) was measured before and after the study period. Overall, the intervention group showed significant increase in levels of 25(OH)D and HF-power, and a significant reduction in the sympathovagal balance (LF/HF). The present findings may have important implications with regard to health improvement.

scholarly journals Objective Measures of Disordered Sleep in Fibromyalgia

2009 ◽  
Vol 36 (9) ◽  
pp. 2009-2016 ◽  
Author(s):  
RONALD D. CHERVIN ◽  
MIHAELA TEODORESCU ◽  
RAMESH KUSHWAHA ◽  
ANDREA M. DELINE ◽  
CHRISTINE B. BRUCKSCH ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Sleep Latency ◽  
Urinary Free Cortisol ◽  
Control Subjects ◽  
Free Cortisol ◽  
Eeg Power ◽  
And Control ◽  
Multiple Sleep Latency

Objective.Patients with fibromyalgia syndrome (FM) complain of inadequate sleep, which could contribute to common symptoms including sleepiness, fatigue, or pain. However, measures that consistently and objectively distinguish FM patients remain elusive.Methods.Fifteen women with FM and 15 age- and gender-matched controls underwent 3 nights of polysomnography; Multiple Sleep Latency Tests to assess sleepiness; testing of auditory arousal thresholds during non-REM stage 2 and stage 4 sleep; overnight assessment of urinary free cortisol; and analysis of 24-hour heart rate variability.Results.On the second night of polysomnography, women with FM in comparison to controls showed more stage shifts (p = 0.04) but did not differ significantly on any other standard polysomnographic measure or on the Multiple Sleep Latency Tests. Alpha EEG power during deep non-REM sleep, alone or as a proportion of alpha power during remaining sleep stages, also failed to distinguish the groups, as did auditory arousal thresholds. Urinary free cortisol did not differ between FM and control subjects in a consistent manner. However, decreased short-term heart rate variability (HRV) and especially ratio-based HRV among FM subjects suggested diminished parasympathetic and increased sympathetic activity, respectively. Other HRV measures suggested decreased complexity of HRV among the FM subjects.Conclusion.Standard measures of sleep, a gold-standard measure of sleepiness, quantified alpha-delta EEG power, auditory arousal thresholds, and urinary free cortisol largely failed to distinguish FM and control subjects. However, HRV analyses showed more promise, as they suggested both increased sympathetic activity and decreased complexity of autonomic nervous system function in FM.

scholarly journals Role of increased sympathetic activity in the genesis of ambulatory ischemia: Spectral analysis of heart rate variability

1996 ◽  
Vol 27 (2) ◽  
pp. 398-399
Author(s):  
Tohru Kaji ◽  
Tetsuro Kohya ◽  
Fumishi Tomita ◽  
Tomohide Ono ◽  
Akira Kitabatake
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Sympathetic Activity

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.

Sign in / Sign up

Export Citation Format

Share Document