Characteristics of cardiotocography in pregnant women with mild COVID-19 in the third trimester.

Objective. To study the characteristics of cardiotocography (CTG) and pregnancy outcomes in patients who had a mild coronavirus infection in the third trimester. Patients and methods. The parameters and variations of CTG and pregnancy outcomes were analyzed in 32 low-risk pregnant women who experienced mild COVID-19 in the third trimester (the study group) and in 30 pregnant women (matched pairs) who had no coronavirus infection (the comparison group). Results. A total of 375 CTGs were analyzed: 221 in the study group and 154 in the comparison group. Normal CTG recordings were found in 87% of pregnant women in the study group, which was significantly less frequent than in those without COVID-19 (97%) (p = 0.02), and suspicious CTG in 10 and 1.3%, respectively, which was 3.38-fold more frequent than in the comparison group (p = 0.04). Pathological CTG recordings were observed only in two women in the study group. The features of CTG in women who had a mild form of COVID-19 in the third trimester were a significant decrease in the number of accelerations, short-term variation (STV) in the range of 3 to 5 ms, long-term variation (LTV) <50 ms, a tendency toward tachycardia and low heart rate variability (<5 ms), and prolonged decelerations. The frequency of fetal asphyxia and neonatal morbidity was higher in the study group. Conclusion. COVID-19 even in its mild form may have a negative effect on the fetus, increasing the frequency of fetal hypoxia and neonatal asphyxia.Copyright © 2023, Dynasty Publishing House. All rights reserved.

Real-time vibration monitoring and analysis of agricultural tractor drivers using an IoT-based system

Agricultural tractor drivers experience a high amplitude of vibration, especially during soil tillage operations. In the past, most research studied vibration exposure with more focus on the vertical (z) axis than on the fore-and-aft (x) and lateral (y) axes. This study examines how rotary soil tillage affects the vibration acceleration and frequency, and the power spectral densities (PSDs) at the seat pan and head along three translational axes in a real-field multiaxis vibration context. Moreover, this study aimed to identify the characteristics of the seat-to-head transmissibility (STHT) response to identifying the most salient resonant frequencies along the x-, y-, and z-axes. Nine (9) male tractor drivers operated the tractor with a mounted rotary tiller throughout the soil tillage process. In the event of a COVID-19 pandemic, and to respect social distancing, this study developed an Internet of Things (IoT) module with the potential to integrate with existing data loggers for online data transmission and to make the experimentation process more effective by removing potential sources of experimenter errors. The raw acceleration data retrieved at the seat pan and the head were utilized to obtain daily exposure (A(8)), PSDs, and STHT along the x-, y-, and z-axes. The vibration energy was found to be dominant along the z-axis than the x- and y-axes. A(8) response among tractor drivers exceeds the exposure action value explicitly stated by Directive 2002/44/EU. PSDs along the x-, y-, and z-axes depicted the low-frequency vibration induced by rotary soil tillage operation. The STHT response exhibited a higher degree of transmissibility along the y- and z-axes when compared with that along the x-axis. The frequency range of 4-7 Hz may plausibly be associated with cognitive impairment in tractor drivers during rotary soil tillage.

The effect of the COVID‐19 pandemic on substance use patterns and physiological dysregulation in pregnant and postpartum women

Background Methods Results Conclusions The SARS‐CoV‐2/COVID‐19 pandemic has been associated with increased stress levels and higher alcohol use, including in pregnant and postpartum women. In the general population, alcohol use is associated with dysregulation in the autonomic nervous system (ANS), which is indexed by heart rate variability (HRV). The objectives of this study were to: (1) characterize changes in substance use during the SARS‐CoV‐2/COVID‐19 pandemic via a baseline self‐report survey followed by mobile ecological momentary assessment (mEMA) of substance use;and (2) examine the associations between momentary substance use and ambulatory HRV measures in pregnant and postpartum women.Pregnant and postpartum women were identified from the ENRICH‐2 prospective cohort study. Participants were administered a baseline structured phone interview that included the Coronavirus Perinatal Experiences (COPE) survey and ascertained the prevalence of substance use. Over a 14‐day period, momentary substance use was assessed three times daily, and HRV measurements were captured via wearable electronics. Associations between momentary substance use and HRV measures (root mean square of successive differences [RMSSD] and low frequency/high frequency [LF/HF] ratio) were examined using a mixed effects model that included within‐subject (WS) and between‐subject (BS) effects and adjusted for pregnancy status and participant age.The sample included 49 pregnant and 22 postpartum women. From a combination of a baseline and 14‐day mEMA surveys, 21.2% reported alcohol use, 16.9% reported marijuana use, and 8.5% reported nicotine use. WS effects for momentary alcohol use were associated with the RMSSD (β = −0.14;p = 0.005) and LF/HF ratio (β = 0.14;p = 0.01) when controlling for pregnancy status and maternal age. No significant associations were observed between HRV measures and instances of marijuana or nicotine use.These findings highlight the negative effect of the SARS‐CoV‐2/COVID‐19 pandemic on the psychological health of pregnant and postpartum women associated with substance use, and in turn, ANS dysregulation, which potentially puts some women at risk of developing a substance use disorder. [ FROM AUTHOR] Copyright of Alcoholism: Clinical & Experimental Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

A Case Report on Heart Rate Variability Biofeedback and Postconcussion Syndrome: Healing the Autonomic Nervous System

Postconcussion syndrome is a devastating condition of the mind, body, and even personality. Mounting research demonstrates that heart rate variability biofeedback can help the concussed individual in three critical ways: (a) eliciting high amplitude oscillations in cardiovascular functions and thereby strengthening self-regulatory control mechanisms;(b) restoring autonomic balance;and (c) increasing the afferent impulse stream from the baroreceptors to restore balance between inhibitory and excitatory processes in the brain.

Major Depressive Disorder and Chronic Fatigue Syndrome Show Characteristic Heart Rate Variability Profiles Reflecting Autonomic Dysregulations: Differentiation by Linear Discriminant Analysis.

Major depressive disorder (MDD) and chronic fatigue syndrome (CFS) have overlapping symptoms, and differentiation is important to administer the proper treatment. The present study aimed to assess the usefulness of heart rate variability (HRV) indices. Frequency-domain HRV indices, including high-frequency (HF) and low-frequency (LF) components, their sum (LF+HF), and their ratio (LF/HF), were measured in a three-behavioral-state paradigm composed of initial rest (Rest), task load (Task), and post-task rest (After) periods to examine autonomic regulation. It was found that HF was low at Rest in both disorders, but was lower in MDD than in CFS. LF and LF+HF at Rest were low only in MDD. Attenuated responses of LF, HF, LF+HF, and LF/HF to task load and an excessive increase in HF at After were found in both disorders. The results indicate that an overall HRV reduction at Rest may support a diagnosis of MDD. HF reduction was found in CFS, but with a lesser severity. Response disturbances of HRV to Task were observed in both disorders, and would suggest the presence of CFS when the baseline HRV has not been reduced. Linear discriminant analysis using HRV indices was able to differentiate MDD from CFS, with a sensitivity and specificity of 91.8% and 100%, respectively. HRV indices in MDD and CFS show both common and different profiles, and can be useful for the differential diagnosis.

Heart Rate Variability and Pregnancy Complications: Systematic Review.

BACKGROUND: The autonomic nervous system (ANS) is known as a critical regulatory system for pregnancy-induced adaptations. If it fails to function, life-threatening pregnancy complications could occur. Hence, understanding and monitoring the underlying mechanism of action for these complications are necessary. OBJECTIVE: We aimed to systematically review the literature concerned with the associations between heart rate variability (HRV), as an ANS biomarker, and pregnancy complications. METHODS: We performed a comprehensive search in the PubMed, Medline Completion, CINAHL Completion, Web of Science Core Collection Classic, Cochrane Library, and SCOPUS databases in February 2022 with no time span limitation. We included studies concerned with the association between any pregnancy complications and HRV, with or without a control group. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline was used for the review of the studies, and Covidence software was used for the study selection process. For data synthesis, we used the guideline by Popay et al. RESULTS: Finally, 12 studies with 6656 participants were included. Despite the methodological divergency that hindered a comprehensive comparison, our findings suggest that ANS is linked with some common pregnancy complications including fetal growth. However, existing studies do not support an association between ANS and gestational diabetes mellitus. Studies that linked pulmonary and central nervous system disorders with ANS function did not provide enough evidence to draw conclusions. CONCLUSIONS: This review highlights the importance of understanding and monitoring the underlying mechanism of ANS in pregnancy-induced adaptations and the need for further research with robust methodology in this area.

Is the Effect of the COVID-19 Vaccine on Heart Rate Variability Permanent?

Background and Objectives: The risk of autonomic dysfunction with COVID-19 vaccines used worldwide in the COVID-19 pandemic remains a topic of debate. Heart rate variability has a number of parameters that can be used to assess autonomic nervous system dynamics. The aim of this study was to investigate the effect of a COVID-19 vaccine (Pfizer-BioNTech) on heart rate variability and autonomic nervous system parameters, and the duration of the effect. Materials and Methods: A total of 75 healthy individuals who visited an outpatient clinic to receive the COVID-19 vaccination were included in this prospective observational study. Heart rate variability parameters were measured before vaccination and on days 2 and 10 after vaccination. SDNN, rMSSD and pNN50 values were evaluated for time series analyses, and LF, HF, and LF/HV values for frequency-dependent analyses. Results: The SDNN and rMSDD values declined significantly on day 2 after vaccination, while the pNN50 and LF/HF values increased significantly on day 10. The values at pre-vaccination and at day 10 were comparable. The pNN50 and LF/HF values declined significantly on day 2 and increased significantly on day 10. The values at pre-vaccination and at day 10 were comparable. Conclusions: This study showed that the decline in HRV observed with COVID-19 vaccination was temporary, and that the Pfizer-BioNTech COVID-19 vaccination did not cause permanent autonomic dysfunction.

Assessing effectiveness of heart rate variability biofeedback to mitigate mental health symptoms: a pilot study.

Introduction: The increasing burden on mental health has become a worldwide concern especially due to its substantial negative social and economic impact. The implementation of prevention actions and psychological interventions is crucial to mitigate these consequences, and evidence supporting its effectiveness would facilitate a more assertive response. Heart rate variability biofeedback (HRV-BF) has been proposed as a potential intervention to improve mental wellbeing through mechanisms in autonomic functioning. The aim of this study is to propose and evaluate the validity of an objective procedure to assess the effectiveness of a HRV-BF protocol in mitigating mental health symptoms in a sample of frontline HCWs (healthcare workers) who worked in the COVID-19 pandemic. Methods: A prospective experimental study applying a HRV-BF protocol was conducted with 21 frontline healthcare workers in 5 weekly sessions. For PRE-POST intervention comparisons, two different approaches were used to evaluate mental health status: applying (a) gold-standard psychometric questionnaires and (b) electrophysiological multiparametric models for chronic and acute stress assessment. Results: After HRV-BF intervention, psychometric questionnaires showed a reduction in mental health symptoms and stress perception. The electrophysiological multiparametric also showed a reduction in chronic stress levels, while the acute stress levels were similar in PRE and POST conditions. A significant reduction in respiratory rate and an increase in some heart rate variability parameters, such as SDNN, LFn, and LF/HF ratio, were also observed after intervention. Conclusion: Our findings suggest that a 5-session HRV-BF protocol is an effective intervention for reducing stress and other mental health symptoms among frontline HCWs who worked during the COVID-19 pandemic. The electrophysiological multiparametric models provide relevant information about the current mental health state, being useful for objectively evaluating the effectiveness of stress-reducing interventions. Further research could replicate the proposed procedure to confirm its feasibility for different samples and specific interventions.

A Biological Approach to Building Resilience and Wellness Capacity Among Police Exposed to Posttraumatic Stress Injuries: Protocol for a Randomized Controlled Trial.

BACKGROUND: Law enforcement officers are routinely exposed to hazardous, disturbing events that can impose severe stress and long-term psychological trauma. As a result, police and other public safety personnel (PSP) are at increased risk of developing posttraumatic stress injuries (PTSIs) and disruptions to the autonomic nervous system (ANS). ANS functioning can be objectively and noninvasively measured by heart rate (HR), heart rate variability (HRV), and respiratory sinus arrhythmia (RSA). Traditional interventions aimed at building resilience among PSP have not adequately addressed the physiological ANS dysregulations that lead to mental and physical health conditions, as well as burnout and fatigue following potential psychological trauma. OBJECTIVE: In this study, we will investigate the efficacy of a web-based Autonomic Modulation Training (AMT) intervention on the following outcomes: (1) reducing self-reported symptoms of PTSI, (2) strengthening ANS physiological resilience and wellness capacity, and (3) exploring how sex and gender are related to baseline differences in psychological and biological PTSI symptoms and response to the AMT intervention. METHODS: The study is comprised of 2 phases. Phase 1 involves the development of the web-based AMT intervention, which includes 1 session of baseline survey measures, 6 weekly sessions that integrate HRV biofeedback (HRVBF) training with meta-cognitive skill practice, and 1 session of follow-up survey measures. Phase 2 will use a cluster randomized control design to test the effectiveness of AMT on the following prepost outcomes: (1) self-report symptoms of PTSI and other wellness measures; (2) physiological indicators of health and resilience including resting HR, HRV, and RSA; and (3) the influence of sex and gender on other outcomes. Participants will be recruited for an 8-week study across Canada in rolling cohorts. RESULTS: The study received grant funding in March 2020 and ethics approval in February 2021. Due to delays related to COVID-19, phase 1 was completed in December 2022, and phase 2 pilot testing began in February 2023. Cohorts of 10 participants in the experimental (AMT) and control (prepost assessment only) groups will continue until a total of 250 participants are tested. Data collection from all phases is expected to conclude in December 2025 but may be extended until the intended sample size is reached. Quantitative analyses of psychological and physiological data will be conducted in conjunction with expert coinvestigators. CONCLUSIONS: There is an urgent need to provide police and PSP with effective training that improves physical and psychological functioning. Given that help-seeking for PTSI is reduced among these occupational groups, AMT is a promising intervention that can be completed in the privacy of one's home. Importantly, AMT is a novel program that uniquely addresses the underlying physiological mechanisms that support resilience and wellness promotion and is tailored to the occupational demands of PSP. TRIAL REGISTRATION: ClinicalTrials.gov NCT05521360; https://clinicaltrials.gov/ct2/show/NCT05521360. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/33492.

The social representation and social action effect of critical issues: autonomic system and self-report measures

By combining words and images that impact emotions and generate empathetic storytelling, advertising (ADV) has evolved into a form of communication for promoting consumer awareness, positive social change, and ADV-related decisional processes, even on topics of high-social relevance such as crisis communication. This study explored consumers' emotional and cognitive responses to crisis-related ADVs using implicit (autonomic) and explicit (self-report) measurements. Nineteen participants watched twelve high-impact social communications about Covid-19, personal health, safety, and prosociality, while autonomic and self-report data were collected. Personal health, safety, and prosociality had higher skin conductance than Covid-19 stimuli, indicating higher arousal and engagement. Personal health reported lower heart rate variability values than Covid-19, suggesting greater emotional reactions for personal health topics, but also lesser mental load for Covid-19 stimuli. Self-report results confirmed autonomic findings. In conclusion, communications about personal health, safety, and prosociality generate higher emotional impact and allow for effective storytelling that facilitates viewer identification, developing a high level of empathy.

Evaluation of Cardiac, Autonomic Functions in Ambulant Patients with Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder caused by dystrophin gene mutation resulting in muscle weakness, motor delays, difficulty in standing, and inability to walk by 12 years. As disease progresses, it leads to cardiac and respiratory failure. Evaluation of cardiac autonomic status and echocardiography in DMD patients at a young age can be a potential biomarker to assess disease progression. This study aimed to investigate the younger DMD population of 5-11years of age with mild to moderate cardiac involvement for early detection using non-invasive and cost-effective tools. Genetically confirmed male DMD patients, aged 5-11 years (n = 47), screened from the outpatient department of a tertiary neuroscience institution were subjected to heart rate variability and echocardiographic analysis, and values were correlated with their clinical variables. DMD patients showed a significantly higher difference in HR, interventricular septum, E m/s, and E-wave to A-wave (E/A) ratio than normal values (p < 0.001). Significantly higher HR indicates initial sinus tachycardia and decreased IVD (d), and increased E m/s and E/A ratio mark the onset of cardiac symptoms in DMD patients even though its chamber dimension remains normal and are associated with cardiac muscle fibrosis.

Characteristics of cardiotocography in pregnant women with mild COVID-19 in the third trimester.

Objective. To study the characteristics of cardiotocography (CTG) and pregnancy outcomes in patients who had a mild coronavirus infection in the third trimester. Patients and methods. The parameters and variations of CTG and pregnancy outcomes were analyzed in 32 low-risk pregnant women who experienced mild COVID-19 in the third trimester (the study group) and in 30 pregnant women (matched pairs) who had no coronavirus infection (the comparison group). Results. A total of 375 CTGs were analyzed: 221 in the study group and 154 in the comparison group. Normal CTG recordings were found in 87% of pregnant women in the study group, which was significantly less frequent than in those without COVID-19 (97%) (p = 0.02), and suspicious CTG in 10 and 1.3%, respectively, which was 3.38-fold more frequent than in the comparison group (p = 0.04). Pathological CTG recordings were observed only in two women in the study group. The features of CTG in women who had a mild form of COVID-19 in the third trimester were a significant decrease in the number of accelerations, short-term variation (STV) in the range of 3 to 5 ms, long-term variation (LTV) <50 ms, a tendency toward tachycardia and low heart rate variability (<5 ms), and prolonged decelerations. The frequency of fetal asphyxia and neonatal morbidity was higher in the study group. Conclusion. COVID-19 even in its mild form may have a negative effect on the fetus, increasing the frequency of fetal hypoxia and neonatal asphyxia.Copyright © 2023, Dynasty Publishing House. All rights reserved.

The effect of exercise using incentive spirometry on heart rate variability in patients after COVID-19 infection

Background: COVID-19 infection causes various sequelae and complications after recovery. Changes in heart rate variability (HRV) were found in patients with COVID-19 infection, suggesting a disturbance in the autonomic system. Breathing exercises with diaphragmatic breathing and incentive spirometry have been shown to increase HRV by increasing lung capacity, respiratory muscle strength, and pulmonary O2 pressure, which can affect baroreflex signals. Incentive spirometry is one of the easy-to-use, safe, inexpensive pulmonary rehabilitation exercises that can be done at home without supervision and are accompanied by a visual display as a guide to the patient. The purpose of the study was to determine the effect of giving breathing exercises using Incentive Spirometry for four weeks on Heart Rate Variability in patients post COVID-19 infection. Method: This research is an experimental study with a pre-post-test control group design. The treatment group was given breathing exercises using Incentive Spirometry, while the control group used diaphragmatic breathing five times a day, seven times per week, for four weeks in each group. HRV measurement was performed before and after four weeks of intervention, using the parameter Root Mean Square of Successive Differences between normal heartbeats (RMSSD), Standard Deviation of N-N intervals (SDNN), and LF/HF ratio of Heart Rate Variability (HRV). Result: There subject of this study was 20 post-COVID-19 patients divided into a treatment group (n=10) and a control group (n=10). There was no significant increase in RMSSD, SDNN, and LF/HF ratio pre and post-intervention in both groups, suggesting no significant increase in HRV. Conclusion: Exercise with Incentive Spirometry and Diaphragmatic Breathing for four weeks did not increase the Heart Rate Variability value in post-COVID-19 patients. © 2023, Sanglah General Hospital. All rights reserved.

Clinical surrogates of dysautonomia predict lethal outcome in COVID-19 on intensive care unit.

BACKGROUND: Unpredictable vegetative deteriorations made the treatment of patients with acute COVID-19 on intensive care unit particularly challenging during the first waves of the pandemic. Clinical correlates of dysautonomia and their impact on the disease course in critically ill COVID-19 patients are unknown. METHODS: We retrospectively analyzed data collected during a single-center observational study (March 2020-November 2021) which was performed at the University Medical Center Hamburg-Eppendorf, a large tertiary medical center in Germany. All patients admitted to ICU due to acute COVID-19 disease during the study period were included (n = 361). Heart rate variability (HRV) and blood pressure variability (BPV) per day were used as clinical surrogates of dysautonomia and compared between survivors and non-survivors at different time points after admission. Intraindividual correlation of vital signs with laboratory parameters were calculated and corrected for age, sex and disease severity. RESULTS: Patients who deceased in ICU had a longer stay (median days ± IQR, survivors 11.0 ± 27.3, non-survivors 14.1 ± 18.7, P = 0.85), in contrast time spent under invasive ventilation was not significantly different (median hours ± IQR, survivors 322 ± 782, non-survivors 286 ± 434, P = 0.29). Reduced HRV and BPV predicted lethal outcome in patients staying on ICU longer than 10 days after adjustment for age, sex, and disease severity. Accordingly, HRV was significantly less correlated with inflammatory markers (e.g. CRP and Procalcitonin) and blood carbon dioxide in non-survivors in comparison to survivors indicating uncoupling between autonomic function and inflammation in non-survivors. CONCLUSIONS: Our study suggests autonomic dysfunction as a contributor to mortality in critically ill COVID-19 patients during the first waves of the pandemic. Serving as a surrogate for disease progression, these findings could contribute to the clinical management of COVID-19 patients admitted to the ICU. Furthermore, the suggested measure of dysautonomia and correlation with other laboratory parameters is non-invasive, simple, and cost-effective and should be evaluated as an additional outcome parameter in septic patients treated in the ICU in the future.

Feasibility of antenatal ambulatory fetal electrocardiography: a systematic review.

BACKGROUND: Antenatal fetal heart rate (FHR) monitoring is currently limited by hospital-based accessibility as well as the availability of relevant equipment and expertise required to position device electrodes. Ambulatory FHR monitoring in the form of noninvasive fetal electrocardiography (NIFECG) is currently an area of research interest, particularly during the era of the COVID-19 pandemic, and the potential to improve maternity care and reduce hospital attendances need to be evaluated. OBJECTIVES: To assess the feasibility, acceptability, and signal success of ambulatory NIFECG monitoring and identify research areas required to facilitate clinical utilization of this method of monitoring. METHODS: Medline, EMBASE, and PubMed databases were searched from January 2005 to April 2021 using terms relevant to antenatal ambulatory or home NIFECG. The search was compliant with PRISMA guidelines, and was registered with the PROSPERO database (CRD42020195809). All studies reporting the clinical utilization of NIFECG inclusive of its use in the ambulatory setting performed in the antenatal period, human studies, and those in the English language were included. Those reporting novel technological methods and electrophysiological algorithms, satisfaction surveys, intrapartum studies, case reports and reviews, and animal studies were excluded. Study screening and data extraction were conducted in duplicate. Risk of bias was appraised using the Modified Downs and Black tool. Due to the heterogeneity of the reported findings, a meta-analysis was not feasible. RESULTS: The search identified 193 citations, where 11 studies were deemed eligible for inclusion. All studies used a single NIFECG system with a duration of monitoring ranging from 5.6 to 21.4 h. Predefined signal acceptance threshold ranged from 34.0-80.0%. Signal success in the study populations was 48.6-95.0% and was not affected by maternal BMI. Good signals were achieved in the 2nd trimester, but less so in the early 3rd trimester. NIFECG was a well-accepted method of FHR monitoring, with up to 90.0% of women's satisfaction levels when worn during outpatient induction of labor. Placement of the acquisition device needed input from healthcare staff in every report. CONCLUSIONS: Although there is evidence for the clinical feasibility of ambulatory NIFECG, the disparity in the literature limits the ability to draw firm conclusions. Further studies to establish repeatability and device validity, whilst developing standardized FHR parameters and set evidence-based standards for signal success for NIFECG are required to ascertain the clinical benefit and potential limitations of ambulatory outpatient FHR monitoring.

Continuous physiological signal measurement over 24-hour periods to assess the impact of work-related stress and workplace violence.

Work-related stress has long been recognized as an essential factor affecting employees' health and wellbeing. Repeated exposure to acute occupational stressors puts workers at high risk for depression, obesity, hypertension, and early death. Assessment of the effects of acute stress on workers' wellbeing usually relies on subjective self-reports, questionnaires, or measuring biometric and biochemical markers in long-cycle time intervals. This study aimed to develop and validate the use of a multiparameter wearable armband for continuous non-invasive monitoring of physiological states. Two worker populations were monitored 24 h/day: six loggers for one day and six ICU nurses working 12-hr shifts for one week. Stress responses in nurses were highly correlated with changes in heart rate variability (HRV) and pulse transit time (PTT). A rise in the low-to high-frequency (LF/LH) ratio in HRV was also coincident with stress responses. HRV on workdays decreased compared to non-work days, and PTT also exhibited a persistent decrease reflecting increased blood pressure. Compared to loggers, nurses were involved in high-intensity work activities 45% more often but were less active on non-work days. The wearable technology was well accepted by all worker participants and yielded high signal quality, critical factors for long-term non-invasive occupational health monitoring.

Design of an App Using the Technique of "Slow-Paced Breathing" for the Self-Regulation for Students During the Coronavirus Disease Pandemic. A Digital Stress-Regulation Program for Students in Grades 6-8

Theoretical background: More than two-thirds of adolescents were moderately to severely burdened during the COVID-19 pandemic and reported lower quality of life as well as increased stress. Inadaequately regulated emotion and negative stress are risk factors for the development of internalization and externalization problems. Students can use an internet-based app for stress regulation training based on slow-paced breathing. This technique is simple and inexpensive and can be used anywhere. Slow-paced breathing stabilizes, calms, and improves physical and mental well-being. This technique can be used in both primary and secondary prevention. Objective: This study is a pilot project intended to investigate the accessibility, acceptance, and effectiveness of an app with the technology of slow-paced breathing. Method: A multimodule app has been designed and developed that explains the technique of slow-paced breathing and guides the use and practice of this technique before or during stressful situations. An additional breathing app provides support. As part of a pilot project during the second wave of the COVID-19 pandemic, students in grades 6 - 8 tested the 4-week training. 31 students evaluated the entire app, and training with the technique of "slow-paced breathing " was evaluated by 7 students. Results: First results indicate that most users were satisfied with the app technology and other aspects, such as design and processing time. The contents of the different modules were rated well by the training group "slow-paced breathing. " On the other hand, the accessibility was considered low, and half of the students (n = 30) would prefer face-to-face stress regulation training in school. All results are presented descriptively. Discussion and conclusion: The revised app plus face-to-face modules for compliance and motivational incentives should be evaluated in a larger sample of teenage students.

Acute effects of different facemasks during High Intensity Interval Training in trained women. A randomized crossover pilot study

The aim of the present investigation was to analyze the acute effect of different facemasks on physiological, perceptual and performance parameters in trained young women during a High Intensity Interval Training (HIIT) on cycle ergometer. Fifteen subjects participated in the study. Heart rate variability, muscle oxygen saturation, lactate concentration and comfort parameters were measured under 3 conditions: no facemask, surgical and FFP2 facemask. The use of facemasks had no effect on any variable related to oxygen saturation, heart rate variability and cycling power during the HIIT protocol. Only lactate concentration revealed significantly lower values in the No mask condition compared to FFP2 3 min after HIIT (p =.038). Regarding the overall perception and comfort, participants reported greater discomfort when wearing the FFP2 mask compared to the No mask condition (p<.05). On the contrary, the analysis of heart rate variability, revealed significant differences (p<.001) in the Pre compared to the Post exercise for all conditions. The use of surgical or FFP2 facemask during HIIT training does not affect performance during strenuous exercise while perceived comfort appears to be lower with FFP2 masks in physically trained women.

COVID-19 and the autonomic nervous system

Background: COVID-19 infection has been shown to have an adverse impact on the cardiovascular system. Cardiac injury, as indicated by elevated cardiac troponin and NT-proBNP levels have been confirmed in COVID-19 cases. There is still ambivalent data on the effect of left ventricular function. Cases of left ventricular impairment, persistent hypotension, acute myopericarditis, myocarditis, arrhythmia and heart failure have been reported in the short term, but there is a significant lacuna when it comes to medium and long-term follow-up of subjects previously infected with COVID-19. Purpose(s): To assess any residual myocardial and autonomic injury in subjects previously infected with COVID-19 at a median follow-up of 5 months. Method(s): A case-control study was performed. Cases were randomly selected subjects who were previously diagnosed with COVID-19 infection following nasopharyngeal swabbing. Controls were subjects who had not been found to be infected with COVID-19 following swabbing and were negative for COVID-19 IgG antibodies. All participants were submitted a standardised questionnaire regarding past medical history. Blood investigations were taken including NT-proBNP and troponin I levels. In addition, all participants underwent 24-hour ambulatory blood pressure monitoring (ABPM) and 24-hour ECG monitoring. The latter was used to assess both for underlying arrhythmias as well as heart rate variability (HRV), a measure of autonomic regulation of the heart. All data was analysed using SPSS version 23.0. Result(s): The study comprised 259 subjects, whereby cases included 174 participants while 75 subjects were age- and gender-matched controls. The study cohort was relatively young with a mean age of 46.1+/-13.8 years. The median follow-up was of approximately 5 months (median 173.5 days, IQR 129-193.25 days). There was no statistically significant difference between cases and controls with regards cardiovascular risk factors and underlying medical conditions. Likewise, there was no difference in blood investigations, including troponin I and NT-proBNP levels at 5-months followup. No difference was noted between the two groups in both awake and asleep blood pressure (BP) readings, as well as dipping BP status. No significant arrhythmias were noted in both groups on 24-hour ECG monitoring. However, when assessing for heart rate variability, it was shown that subjects who had been previously infected with COVID-19 exhibited lower root-mean square differences of successive R-R intervals (RMSSD), p=0.028. This indicates poor vagus nerve-mediated autonomic control of the heart. Conclusion(s): Subjects previously infected with COVID-19 exhibited lower HRV as exhibited by low RMSSD as compared to controls. Reduced HRV is a known biomarker for mortality and sudden death in cardiac disease. The possible long-term implications of reduced HRV in subjects previously infected with COVID-19 merits further investigation.

Research on fatigue identification methods based on low-load wearable ECG monitoring devices

The identification of fatigue in personal workers in particular environments can be achieved through early warning techniques. In order to prevent excessive fatigue of medical workers staying in infected areas in the early phase of the coronavirus disease pandemic, a system of low-load wearable electrocardiogram (ECG) devices was used as intelligent acquisition terminals to perform a continuous measurement ECG collection. While machine learning (ML) algorithms and heart rate variability (HRV) offer the promise of fatigue detection for many, there is a demand for ever-increasing reliability in this area, especially in real-life activities. This study proposes a random forest-based classification ML model to identify the four categories of fatigue levels in frontline medical workers using HRV. Based on the wavelet transform in ECG signal processing, stationary wavelet transform was applied to eliminate the main perturbation of ECG in the motion state. Feature selection was performed using ReliefF weighting analysis in combination with redundancy analysis to optimize modeling accuracy. The experimental results of the overall fatigue identification achieved an accuracy of 97.9% with an AUC value of 0.99. With the four-category identification model, the accuracy is 85.6%. These results proved that fatigue analysis based on low-load wearable ECG monitoring at low exertion can accurately determine the level of fatigue of caregivers and provide further ideas for researchers working on fatigue identification in special environments. © 2023 Author(s).