Decrease In Parasympathetic Activity Research Articles

Insight of autonomic dysfunction in CLN3 disease: a study on episodes resembling paroxysmal sympathetic hyperactivity (PSH)

BackgroundRecurrent non-epileptic episodes resembling paroxysmal sympathetic hyperactivity (PSH) have been observed in adolescents with Juvenile Ceroid Lipofuscinosis (CLN3-disease) and a possible association to an autonomic dysfunction has been suggested. The objective of the present study was to investigate the dynamics of the autonomic activity up to, during, and in the time after individual attacks. We include all seven suitable CLN3 patients in Denmark ≥ 15 years of age. HRV parameters were assessed from continuous heart rate monitoring during seven consecutive days and a particular focus of HRV parameters was obtained in close temporal context to clinically recurrent PSH-like episodes. In addition, the likelihood of PSH was assessed by caregiver’s description and by video documentation.ResultsRespectively eight and five episodes were recorded in two patients (18 and 20 years of age). The episodes were all safely superior to the cut off values of the clinical assessment score to be considered PSH-like episodes. During all 13 episodes, HRV revealed a statistically significant decrease in root mean square of successive differences (RMSSD) and standard deviation of the Poincaré-Plot interval (SD1) in the minutes prior to the clinical onset of the episodes, both indicating a sudden decrease in parasympathetic activity in advance of the onset. The reduced activity remained low during the episodes, and 15–30 min following the attack cessation, the parasympathetic activity had returned to pre-attacks levels. The sympathetic HRV parameters were unchanged resulting in a sympathetic overactivity during the episodes. In a third participant (32 years of age), in whom severity of PSH-like episodes had been gradually reduced during the last years, five episodes were registered. A similar temporally related reduction of the parasympathetic activity was found, but because the sympathetic activity decreased as well, no sympathetic dominance developed, which most reasonable is the reason to the clinically reduced expression of the episodes.ConclusionThe documented transient withdrawal of parasympathetic activity leading to a paroxysmal unbalanced sympathetic hyperactivity most probably accounts for the PSH-like episodes occurring in post-adolescent CLN3 patients. The findings shed new light on both aetiology and possible preventative and therapeutic measures.

The Impact on Autonomic Nervous System Activity during and Following Exercise in Adults: A Meta-Regression Study and Trial Sequential Analysis.

Background and Objectives: Exercise enhances cardiovascular health through various mechanisms, including the modulation of autonomic nervous system activity. This study aimed to systematically examine the impact of exercise on heart rate variability (HRV) in adults during and within one hour after exercise (WHAE). Materials and Methods: A comprehensive literature review was conducted using the MEDLINE, Embase, Cochrane Library, Scopus, and PubMed databases to identify published studies that reported the impact of exercise on autonomic nervous system activity in adults. The studies measured the absolute power of the low-frequency band (0.04-0.15 Hz) to the absolute power of the high-frequency band (0.015-0.4 Hz) (LF/HF ratio) to assess sympathetic activity and the root mean square of successive differences between normal heartbeats (RMSSD) to assess parasympathetic activity. Results: A total of 3329 studies were screened for relevance, and finally, 10 articles that utilized methods for measuring autonomic nervous system activity, such as the LF/HF ratio and RMSSD, covering 292 adult patients, were included for meta-analysis. In the current meta-analysis, we observed a significant decrease in parasympathetic activity during and after exercise, as indicated by RMSSD, compared to pre-exercise levels (mean difference [MD] = -4.96, 95% confidence interval [CI]: -8.00 to -1.91, p = 0.003). However, sympathetic activity after exercise, represented by the LF/HF ratio, showed a borderline significant increase compared to pre-exercise levels (MD = 1.06, 95% CI: -0.01 to 2.12, p = 0.052). The meta-regression model found that factors associated with RMSSD included mean age, male gender, and duration post-exercise. Additionally, the factor associated with the LF/HF ratio was the healthy condition of participants. The trial sequential analysis provided robust evidence of a decrease in RMSSD and an increase in the LF/HF ratio during and WHAE. Conclusions: Given the limitations of the current study, the findings suggest that a significant decrease in parasympathetic activity and a borderline significant increase in sympathetic activity in adults during and WHAE, as confirmed by trial sequential analysis. Meta-regression analysis indicated that parasympathetic activity was negatively associated with participant age and male gender, but positively associated with duration post-exercise. Additionally, increased sympathetic activity was linked to the healthy conditions of participants. This study suggests that exercise might differentially affect autonomic balance in individuals with chronic conditions compared to healthy individuals. This highlights the potential need for tailored exercise interventions to improve autonomic function across different populations.

Effects of participant-selected versus researcher-selected music on stress and mood – The role of gender

ObjectivePrevious research suggests differential effects of participant-selected (PS) vs. researcher-selected (RS) music on emotional responses to music listening. This study investigates whether such selection strategies, as well as gender, influence (1) stress and (2) mood responses. Additionally, we examine the role of (3) stimulus-induced emotions and (4) emotion regulation strategies. MethodsParticipants (N = 61) listened to auditory stimuli (PS music, RS music, sound of lapping water (LW); randomized) on three days and underwent a cold pressor test (CPT) while listening. Stress parameters (subjective acute stress, heart rate, parameter RMSSD, salivary alpha-amylase, salivary cortisol), mood dimensions (calmness, valence, energetic arousal), emotions, and emotion regulation strategies were measured. Multilevel and mediation analyses were conducted. Results(1) There were no direct effects of selection strategy or gender on stress responses, but interaction effects indicated that women showed the strongest subjective stress response and the longest HR recovery with PS music, while men showed the lowest HR response to the CPT with PS music. (2) No mood differences emerged between PS and RS music overall. Women showed stronger variability in calmness overall as well as perceived higher arousal when listening to PS music compared to men. (3) Higher stimulus-induced anger in men compared to women and with LW compared to PS was associated with lower calmness and valence, while no consistent pattern emerged for the stress responses. (4) Women scored higher on reappraisal, associated with a decrease in parasympathetic activity, whereas men scored higher on suppression, associated with an increase in endocrine activity. ConclusionsMusic selection and gender appear to have no direct impact on stress and mood responses overall, although men tend to benefit more from self-selected music than women. Our findings provide first indications that avoiding music stimuli that induce anger may facilitate mood management via music. Furthermore, finding alternative emotion regulation strategies to the strategy of suppression may be a helpful approach to improve music-based stress management.

Effect of Preferential Relaxing Music on Exercise-Induced Changes in Autonomic Function of the Heart

Context: Music has been used for healing purposes since ancient times. Music therapy is a growing branch which can facilitate and promote a healthy mind and body. Autonomic nervous system (ANS) may serve as one path by which music exerts its therapeutic effects. Interaction between the ANS and cardiovascular system during exercise can be of prognostic importance in many cardiovascular diseases. The measurement of the effects of musical auditory stimulation, using non-invasive test of heart rate variability (HRV), on cardiac auditory response while under stressful condition, like exercise, would help understand the usability of musical interventions in prevention and treatment of cardiovascular diseases. Aim: To gauge the effects of preferential relaxing music on exercise-induced changes in frequency domain parameters (LF, low frequency; HF, high frequency; LF: HF ratio) of HRV. Setting and Design: Experimental study design. Methods and Materials: Sample size—52 healthy young adult volunteers (18–25 years). HRV was measured from the ECG obtained at rest, while listening to preferential relaxing music, after doing moderate exercise and after doing moderate exercise while listening to preferential relaxing music. Statistical Analysis Used: Comparison of frequency domain HRV variables was done using paired t-test. Results: Non-significant increase in HF component (P value = 0.3) and non-significant decrease in LF: HF ratio (P value = 0.06) after doing moderate exercise with music when compared with after doing moderate exercise without music was observed. Conclusion: Preferential relaxing music attenuated exercise-induced decrease in parasympathetic activity post-exercise.

Heart Rate Variability during Virtual Reality Activity in Individuals after Hospitalization for COVID-19: A Cross-Sectional Control Study

(1) Background: COVID-19 can lead to many complications, including cardiorespiratory complications and dysautonomia. This can be assessed by heart rate variability (HRV), which reflects the autonomic nervous system. There are different possibilities for physical rehabilitation after COVID, one of which that has been growing fast is the use of Virtual reality (VR) for rehabilitation. VR may represent an innovative and effective tool to minimize deficits that could lead to permanent disabilities in patients of outpatient rehabilitation services. The aim of this protocol is to establish whether practicing a task using a VR game with body movements influences physiological variables, such as heart rate, HRV, oxygen saturation, blood pressure, and perceptual variables during exercise in individuals post-hospitalization for COVID. (2) Methods: This cross-sectional study evaluated individuals divided into two groups, a post-hospitalization for COVID-19 group and a healthy control group. Subjects underwent one session of a VR task, and physiological variables, including HRV, were measured during rest, VR activity, and recovery. In addition, considering the influence of age in HRV and the impact of COVID-19, we divided participants by age. (3) Results: In all HRV indices and in both groups, an increase in sympathetic and a decrease in parasympathetic activity were found during VR. Additionally, the older post-COVID-19 group performed worse in non-linear indices, peripheral oxygen saturation, and rating of perceived exertion (RPE). (4) Conclusions: The VR game positively affects physiological variables and can therefore be utilized as a secure physical activity in both healthy individuals and individuals after hospitalization for COVID-19. COVID-19 affects the autonomic nervous system of older patients’ post-hospitalization, which may be partly due to a higher BMI and the reduced exercise capacity in this population, affecting their ability to perform exercise activities. Other important observations were the higher RPE in COVID-19 patients during and after exercise, which may reflect altered physiological and autonomic responses. Taken together with the high reporting of fatigue after COVID-19, this is an important finding, and considering that RPE is usually lower during VR exercise compared to non-VR strengthens the potential for the use of VR in COVID-19 patients.

Cardiac Functional and Structural Abnormalities in a Mouse Model of CDKL5 Deficiency Disorder.

CDKL5 (cyclin-dependent kinase-like 5) deficiency disorder (CDD) is a severe neurodevelopmental disease that mostly affects girls, who are heterozygous for mutations in the X-linked CDKL5 gene. Mutations in the CDKL5 gene lead to a lack of CDKL5 protein expression or function and cause numerous clinical features, including early-onset seizures, marked hypotonia, autistic features, gastrointestinal problems, and severe neurodevelopmental impairment. Mouse models of CDD recapitulate several aspects of CDD symptomology, including cognitive impairments, motor deficits, and autistic-like features, and have been useful to dissect the role of CDKL5 in brain development and function. However, our current knowledge of the function of CDKL5 in other organs/tissues besides the brain is still quite limited, reducing the possibility of broad-spectrum interventions. Here, for the first time, we report the presence of cardiac function/structure alterations in heterozygous Cdkl5 +/- female mice. We found a prolonged QT interval (corrected for the heart rate, QTc) and increased heart rate in Cdkl5 +/- mice. These changes correlate with a marked decrease in parasympathetic activity to the heart and in the expression of the Scn5a and Hcn4 voltage-gated channels. Interestingly, Cdkl5 +/- hearts showed increased fibrosis, altered gap junction organization and connexin-43 expression, mitochondrial dysfunction, and increased ROS production. Together, these findings not only contribute to our understanding of the role of CDKL5 in heart structure/function but also document a novel preclinical phenotype for future therapeutic investigation.

Prolonged asystole induced by trigeminocardiac reflex accompanied with abnormal heart rate variability during percutaneous balloon compression: a case report.

Trigeminocardiac reflex (TCR) can result in bradycardia and even cardiac arrest, and is reversible with elimination of the stimulus. Here, we report the case of a 68-year-old man who experienced cardiac arrest during percutaneous balloon compression for the treatment of trigeminal neuralgia. In this patient, sinus rhythm did not recover after stimulation removal, causing us to successfully perform cardiopulmonary resuscitation (CPR). The patient regained a sinus rhythm and was pretreated with atropine 0.5 mg, allowing the operation to be started again. The operation was completed successfully and the patient experienced no complications. Subsequent heart rate variability (HRV) analysis showed that parasympathetic activity predominated before anesthesia induction and after tracheal intubation. It further elevated during foramen ovale puncture, leading to prolonged asystole. Fortunately, sympathetic activity predominated after atropine was administered, which manifested as an increase in sympathetic activity and a decrease in parasympathetic activity. This could be beneficial for patients with TCR. This case indicates that TCR-related cardiac arrest might not be reversed with stimulus cessation, and atropine played a key role in preventing TCR. Moreover, HRV analysis might be essential for preoperative screening for high-risk patients. We also reviewed the literature for cases of TCR with prolonged asystole.

Сardiorespiratory relationships in people of young age depending on the composite composition of the body

BACKGROUND: The decisive importance of the sympathetic and parasympathetic nervous system in maintaining vegetative homeostasis requires the determination of sensitive non-invasive parameters of multidimensional outpatient monitoring of cardiorespiratory adaptation under various physiological and clinical conditions, taking into account the function of external respiration (FER), compound body composition and heart rate variability (HRV).AIM: To identify concomitant changes in HRV, HR and compound body composition in young people as markers of cardiorespiratory adaptation and rehabilitation.MATERIALS AND METHODS: On the basis of the Kuban State Medical University, a single-centre, interventional, cross-sectional, single-sample, comparative, uncontrolled study of a general group of young people in which respiratory parameters and parameters of the compound body composition were determined. Some individuals in this group additionally underwent Holter monitoring of the electrocardiogram (ECG) at short intervals.RESULTS: In young people, a change in the compound body composition with an increase in total fat mass, visceral and body fat is associated with a decrease in respiratory function (a decrease in the Tiffno index, a decrease in the maximum middle-expiratory flow — MMEF), manifested by a decrease in HRV (according to the TI indicator), the absence of an increase in the autonomic regulation circuit (according to SDNN indicator), a decrease in parasympathetic activity (in terms of rMSSD) and the absence of sympathetic activation (in terms of SDANN). Positive shifts in the form of an increase in trunk muscles, the total amount of water and a decrease in the total fat mass are accompanied by an increase in lung capacity, forced expiratory volume in the first second and a change in HRV with sympathetic (in terms of LF / HF, SDANN) and parasympathetic activation (in terms of rMSSD), an increase in HRV (in terms of TI) and an increase in the autonomic regulation circuit of the vegetative nervous system (in terms of SDNN).CONCLUSION: Accurate and rapid diagnostics of vegetative homeostasis requires a comprehensive correlative analysis of the parameters characterizing HRV in short recordings, the compound composition of the human body and respiratory function.

Heart rate variability and cortisol levels in school-age children with different cognitive tests

Background. An urgent task of age-related physiology is to study the functional state of the body of school-age children in cognitive activity due to the large academic load and the use of information and computer technologies in the educational process to identify the characteristics of the reactivity of the body of students when performing cognitive load of various types, including on electronic devices, is necessary for the organization of the school educational environment.The aim. To assess the nature of vegetative, cardiovascular and hormonal reactivity in cognitive load of various types in school-age children.Materials and methods. By methods of heart rate variability analysis, electrocardiography, tonometry and enzyme immunoassay of cortisol in saliva, 117 school-age children were examined while performing cognitive load of various types.Results. There is a change in heart rate variability indicators while performing cognitive load. Oral counting causes an increase in sympathetic influences on the heart rate with a decrease in parasympathetic activity, as well as a shift in the vagosympathetic balance. Operation on the electronic devices causes a decrease in the total power density of the spectrum and an increase in the index of low-frequency and highfrequency vibrations ratio due to a decrease in parasympathetic activity. Two types of reaction were revealed: type I – an increase in the concentration of cortisol in saliva, an increase in sympathetic effects on Heart rate with a simultaneous decrease in parasympathetic activity (counting), a decrease in the total power of the spectrum density (laptop), a decrease in parasympathetic activity (tablet). Type II – a decrease in hormone levels and a decrease in very low-frequency vibrations and parasympathetic activity, regardless of the type of load presentedConclusion. The results obtained indicate that the nature of the reactivity of heart rate indicators and the stress hormone cortisol in students depends not so much on which electronic device it is performed on, but on the type of cognitive load.

Obesity and heart rate variability: A cross-sectional study in obese young adults

CONTEXT: Obesity is one of the important causative factors for multiple co-morbid conditions that can lead to metabolic and cardiac disorders. Many research studies indicate the association of obesity and sudden cardiac deaths.AIMS: This study was aimed to evaluate the cardiac autonomic nervous system activity, given by the changes in heart rate variability (HRV) in healthy obese young adults.SETTINGS AND DESIGN: This cross-sectional study included thirty obese young adult males of 18–25 years and 30 age-matched healthy adult males. Power spectral analysis of HRV was used to determine the autonomic imbalance.SUBJECTS AND METHODS: HRV was performed using HRV software (Lab Chart 7). Numerical data of absolute values of low frequency (LF) and high frequency (HF) (in ms2), normalized units of LF and HF (in nu) and LF/HF ratio were expressed as mean ± standard deviation and analyzed.RESULTS: On statistical analysis, it was found that HF in normalized units was significantly low in obese young adults compared to age-matched controls. LF (nu) and LF/HF ratio were higher in obese subjects compared to controls, though they were not statistically significant. Although there was negative correlation between HRV parameters and body mass index in obese individuals, it was not significant.CONCLUSIONS: These results suggest that obese young adults present with changes in the autonomic nervous system, characterized by decrease in parasympathetic activity.

Similar Supine Heart Rate Variability Changes During 24-h Exposure to Normobaric vs. Hypobaric Hypoxia.

Purpose: This study aimed to investigate the differences between normobaric (NH) and hypobaric hypoxia (HH) on supine heart rate variability (HRV) during a 24-h exposure. We hypothesized a greater decrease in parasympathetic-related parameters in HH than in NH.Methods: A pooling of original data from forty-one healthy lowland trained men was analyzed. They were exposed to altitude either in NH (FIO2 = 15.7 ± 2.0%; PB = 698 ± 25 mmHg) or HH (FIO2 = 20.9%; PB = 534 ± 42 mmHg) in a randomized order. Pulse oximeter oxygen saturation (SpO2), heart rate (HR), and supine HRV were measured during a 7-min rest period three times: before (in normobaric normoxia, NN), after 12 (H12), and 24 h (H24) of either NH or HH exposure. HRV parameters were analyzed for time- and frequency-domains.Results: SpO2 was lower in both hypoxic conditions than in NN and was higher in NH than HH at H24. Subjects showed similarly higher HR during both hypoxic conditions than in NN. No difference in HRV parameters was found between NH and HH at any time. The natural logarithm of root mean square of the successive differences (LnRMSSD) and the high frequency spectral power (HF), which reflect parasympathetic activity, decreased similarly in NH and HH when compared to NN.Conclusion: Despite SpO2 differences, changes in supine HRV parameters during 24-h exposure were similar between NH and HH conditions indicating a similar decrease in parasympathetic activity. Therefore, HRV can be analyzed similarly in NH and HH conditions.

Initial vegetative tone in mild atopic asthma in children

Background. In most industrialized countries, allergic diseases affect up to 20% of the population. This pathology belongs to the most common in children: according to the World Health Organization, more than 15% of the world's child population suffers from it. In recent years, there has been a significant increase in the frequency and more severe course of these diseases, in connection with which they are considered in modern society as a major medical and social problem. Thus, the prevalence of bronchial asthma, according to domestic and foreign authors, ranges from 0.2 to 8.1%. Purpose. In order to clarify the role of the autonomic nervous system in the genesis of the mild course of atopic bronchial asthma in childhood, the features of the interaction of the sympathetic and parasympathetic divisions of the autonomic nervous system in the examined children were clarified. Materials and methods. 126 children aged 10 to 14 years were examined. Atopic bronchial asthma was diagnosed in 91 children. At the same time, 61 of them were diagnosed with an intermittent course, 30 a mild persistent course of the disease. The control group consisted of 35 healthy children also aged 10 to 14 years. Complaints, anamnesis data were studied in all children, an objective and generally accepted laboratory and instrumental examination was carried out. All examined children underwent daily monitoring of the electrocardiogram, according to the results of which, based on the analysis of time and frequency indicators of heart rate variability, a variant of the initial autonomic tone was established. Results. In children with atopic bronchial asthma, both with intermittent and mild persistent course, an absolute or relative dominance of sympathetic influences was revealed against the background of varying degrees of decrease in parasympathetic activity, which was interpreted as a compensatory reaction of the body in response to chronic allergic inflammation.

Benefits of pharmacological and electrical cholinergic stimulation in hypertension and heart failure.

Systemic arterial hypertension and heart failure are cardiovascular diseases that affect millions of individuals worldwide. They are characterized by a change in the autonomic nervous system balance, highlighted by an increase in sympathetic activity associated with a decrease in parasympathetic activity. Most therapeutic approaches seek to treat these diseases by medications that attenuate sympathetic activity. However, there is a growing number of studies demonstrating that the improvement of parasympathetic function, by means of pharmacological or electrical stimulation, can be an effective tool for the treatment of these cardiovascular diseases. Therefore, this review aims to describe the advances reported by experimental and clinical studies that addressed the potential of cholinergic stimulation to prevent autonomic and cardiovascular imbalance in hypertension and heart failure. Overall, the published data reviewed demonstrate that the use of central or peripheral acetylcholinesterase inhibitors is efficient to improve the autonomic imbalance and hemodynamic changes observed in heart failure and hypertension. Of note, the baroreflex and the vagus nerve activation have been shown to be safe and effective approaches to be used as an alternative treatment for these cardiovascular diseases. In conclusion, pharmacological and electrical stimulation of the parasympathetic nervous system has the potential to be used as a therapeutic tool for the treatment of hypertension and heart failure, deserving to be more explored in the clinical setting.

Sleep Deprivation Deteriorates Heart Rate Variability and Photoplethysmography.

IntroductionSleep deprivation has deleterious effects on cardiovascular health. Using wearable health trackers, non-invasive physiological signals, such as heart rate variability (HRV), photoplethysmography (PPG), and baroreflex sensitivity (BRS) can be analyzed for detection of the effects of partial sleep deprivation on cardiovascular responses.MethodsFifteen participants underwent 1 week of baseline recording (BSL, usual day activity and sleep) followed by 3 days with 3 h of sleep per night (SDP), followed by 1 week of recovery with sleep ad lib (RCV). HRV was recorded using an orthostatic test every morning [root mean square of the successive differences (RMSSD), power in the low-frequency (LF) and high-frequency (HF) bands, and normalized power nLF and nHF were computed]; PPG and polysomnography (PSG) were recorded overnight. Continuous blood pressure and psychomotor vigilance task were also recorded. A questionnaire of subjective fatigue, sleepiness, and mood states was filled regularly.ResultsRMSSD and HF decreased while nLF increased during SDP, indicating a decrease in parasympathetic activity and a potential increase in sympathetic activity. PPG parameters indicated a decrease in amplitude and duration of the waveforms of the systolic and diastolic periods, which is compatible with increases in sympathetic activity and vascular tone. PSG showed a rebound of sleep duration, efficiency, and deep sleep in RCV compared to BSL. BRS remained unchanged while vigilance decreased during SDP. Questionnaires showed an increased subjective fatigue and sleepiness during SDP.ConclusionHRV and PPG are two markers easily measured with wearable devices and modified by partial sleep deprivation, contradictory to BRS. Both markers showed a decrease in parasympathetic activity, known as detrimental to cardiovascular health.

Assessments of Heart Rate and Sympathetic and Parasympathetic Nervous Activities of Normal Mouse Fetuses at Different Stages of Fetal Development Using Fetal Electrocardiography

Heart rate is controlled by the activity of the autonomic nervous system: the sympathetic and parasympathetic nervous systems increase and suppress heart rate, respectively. To evaluate the activity of the autonomic nervous system, it is possible to determine heart rate variability using electrocardiography (ECG). During the fetal period, the heart and autonomic nerves develop in coordination; however, physiological changes, including autonomic nervous activities that occur during the fetal stage, remain largely unknown. Therefore, in this study, we measured ECG signals of mouse fetuses using our established method to evaluate the development of heart rate and autonomic nervous activity at different fetal developmental stages. We found that heart rate was significantly increased in fetal mice at embryonic day (E) 18.5 compared with that at E13.5, E15.5, and E17.5, indicating that fetal heart rate increases only at the stage immediately prior to birth. Interestingly, fetal parasympathetic nervous activity was reduced at E17.5 and E18.5 compared with that at E13.5, whereas fetal sympathetic nervous activity remained unchanged, at least from E13.5 to E18.5. These results indicate that parasympathetic activity rather than sympathetic activity affects fetal heart rate and that the decrease in parasympathetic activity toward the end of pregnancy could result in the observed increase in fetal heart rate.

A235 EFFECTS OF SACRAL PHOTOBIOMODULATION ON THE AUTONOMIC NERVOUS SYSTEM IN PATIENTS WITH COLONIC DYSMOTILITY

BackgroundPatients with chronic refractory constipation show colon dysmotility, including impaired coordination of descending colon-sigmoid colon-rectum-anal sphincter motor functions; this may involve slow colonic transit and colo-anal dyssynergia. Impaired neuronal communication between the sacral defecation center and the distal colon may be causative. In addition, patients with lumbosacral neurological conditions (with lower back pain) may not be able to evoke an effective defecation reflex.AimsTo evaluate if a single therapeutic session of sacral low-level laser therapy (LLLT) would affect the autonomic activity in patients with chronic constipation as revealed by changes in heart rate variability, and to report a multi-session treatment case study.MethodsIn 41 patients with chronic constipation, one session of LLLT was executed, using red LED light at a wavelength of 660 nm for 10 minutes and infrared LED light at wavelength of 840 nm for 10 minutes followed by infrared laser light with wavelength of 825 nm for 20 minutes, while measuring the electrocardiogram. One patient received this treatment 8x over 3 weeks.ResultsThe lumbar-sacral light array treatment showed a significant decrease in parasympathetic activity (RSA & RMSSD) whereas pure sacral laser light treatment showed a significant increase in parasympathetic activity (RSA & RMSSD) as well as a reduction in sympathetic activity (Baevsky’s stress index: SI) (table). A single session of LLLT was also executed during HRCM in 8 patients with some but not all showing evoked colonic motility. Before COVID-19 shutdown, one patient was successfully treated. With a history of chronic constipation without ability to have spontaneous bowel movements for 5 years, symptoms improved from 13 to 8 (on a 20 scale) and quality of life improved from 1.5 to 2.5 (on a 0–4 scale) after 8 sessions. Sympathetic reactivity from supine to standing markedly reduced, from highly elevated measured as the Baevsky index from 55 to 153 s-2 it improved from 42 to 75 s-2 upon standing after 4 sessions. Parasympathetic reactivity did not change.ConclusionsA single session of sacral LLLT markedly affected autonomic nervous activity reflected in changes in HRV. The LLLT is likely affecting the sacral defecation center through peripheral nerves entering and exiting the spinal cord including the dorsal root ganglia. LLLT treatment of a patient with inability to generate spontaneous bowel movements, resulted in ability to have complete evacuations associated with marked reduction in sympathetic reactivity during the supine-standing test, after 4 LLLT sessions. Funding AgenciesCIHRFarncombe Family Digestive Health Research Institute

Comparison of Heart Rate Variability between Shift and Rest Days in Nurses Working at Coronary Intensive Care Unit

Objective: Stress of working conditions change the circadian rhythm and body’s autonomic functions. Heart rate variability is a simple and noninvasive method that reflects the heart’s autonomic system. In this study, we analyzed the rhythm differences of intensive care unit nurses between 24 hours shift and rest days.
 Materials and Methods: 51 nurses working in intensive care units of our center were included in the study. The nurses were divided into two groups as study and control groups according to the shift and rest days for 24 hours holter recordings, respectively.
 Results: Heart rate parameters were under parasympathic and sympathic dominance in rest and shift days, respectively. Although normalized high frequency, normalized low frequency and low frequency/high frequency ratio values were parallel to the shift and rest days at 24-hour intervals, inverse correlations were observed between 03.00- 08.00 hours. No statistically significant difference was seen in circadian rhythm between shift and rest days. Heart rate parameters generally showed similar pattern of circadian rhythm irrespective of the working status of the participants. Sympathetic activity was significantly higher in the day period than the night period in the shift days however there was no difference within resting group.
 Conclusion: Slight increase in sympathetic system activity and marked decrease in parasympathetic activity during 03-05 o’clock were apparent in shift days. This increase was attributed to early cortisol release.

Prevalence of stress among first year medical students and its effect on heart rate variability

Background: A high prevalence of stress is seen among 1st-year medical students. Stress has profound effects on mental and physical health and is seen to affect the autonomic balance with an increase in sympathetic and a decrease in parasympathetic activity. Aim and Objectives: The objectives of the study were to estimate the prevalence of stress among 1st-year medical students, the distribution of stress in both genders and the association of heart rate variability (HRV) with stress. Materials and Methods: A cross-sectional analytical study was conducted among 70 1st-year medical students (35 males and 35 females) aged between 18 and 23 years. A self-scoring medical students stress questionnaire was used to assess their degrees of stress. Short-term HRV was recorded by lead II electrocardiogram (ECG) using physiopac. Results: The prevalence of stress was found to be 97.2% among 1st-year medical students. Majority (65.7%) of females had severe stress, while majority of males (51.4%) had only mild to moderate stress. Although not significant, the mean values of low frequency (LF) power, normalized LF, and LF to high frequency (LF/HF) ratio were higher in mild to moderate and severe groups, compared to no stress group. The mean values of normalized HF were found to be lower in mild to moderate stress and severe stress groups, compared to no stress group, which was also not significant. Conclusion: The 1st-year medical students are stressed, with more stress among females. It is found to affect their autonomic balance reflected in their HRV values. Hence, to reduce stress, they are advised to adopt various stress-relieving measures.

Effects of physiotherapy associated to virtual games in pain perception and heart rate variability in cases of low back pain

Introduction: The virtual games when appropriately used can stimulate brain activity and excite the creative energy. Therefore, it is important to assess the implications of their use in pain perception in individuals with low back pain (LBP), a disease that affects about 80% of the world’s population. Objective: was to evaluate the effects of virtual games combined with a physiotherapy program on the pain perception and Heart Rate Variability (HRV) in people with LBP. Method: the participants were 21 adults with clinical diagnosis of LBP, aged 24-61 years, of both sexes, divided into two groups. Five weekly meetings were provided. Group 1 participated in a physical therapy program and group 2 participated in the same physical therapy program plus joint sessions with virtual games. The instruments used were a heart rate monitor; a tablet for games; a shortwave equipment; visual analogue scale (VAS); and McGill’s Pain Questionnaire. The measurements were performed before and after the program. Results: Reduction in pain was observed in both groups, being higher in group 2, the one that used the games. Conclusion: There was a decrease in parasympathetic activity in group 2, which indicates that the distraction factor promoted by the games influenced the pain perception.

Lay theory of generalized prejudice moderates cardiovascular stress responses to racism for White women

Research on stigma by prejudice transfer has demonstrated that White women anticipate sexism when interacting with a racist individual due to a belief that prejudices stem from an underlying ideology of group inequality. The present research proposes that individuals’ lay theory of generalized prejudice (LTGP) varies across individuals and examines cardiovascular stress responses (high frequency heart rate variability [HF-HRV] and preejection period [PEP]). White women who held a lay theory of generalized prejudice and were evaluated by a White man with negative attitudes towards Black Americans demonstrated greater cardiovascular reactivity (decreases in parasympathetic activity [Studies 1 and 2] and shortened PEP [Study 2] from baseline to evaluation) than White women being evaluated by a neutral evaluator or who did not hold a lay theory of generalized prejudice. The present studies are the first to demonstrate cardiovascular stress responses to stigma by prejudice transfer and to highlight LTGP as a key individual difference in stigma by prejudice transfer.