Reduced Heart Rate Variability Research Articles

Relation between heart rate variability and spectral analysis of electroencephalogram in chronic neuropathic pain patients.

Chronic neuropathic pain (CNP) is a complex condition often arising from neural maladaptation after nerve injury. Understanding CNP complications involves the intricate interplay between brain-heart dynamics, assessed through quantitative electroencephalogram (qEEG) and heart rate variability (HRV). However, insights into their interaction in chronic pain are limited. Resting EEG and simultaneous electrocardiogram (lead II) of the participants were recorded for qEEG and HRV analysis. Correlations between HRV and qEEG parameters were calculated and compared with age, sex, and body mass index (BMI)-matched controls. CNP patients showed reduced HRV and significant increases in qEEG power spectral densities within delta, theta, and beta frequency ranges. A positive correlation was found between low frequency/ high frequency (LF/HF) ratio in HRV analysis and theta, alpha, and beta frequency bands in qEEG among CNP patients. However, no significant correlation was observed between parasympathetic indices and theta, beta bands in qEEG within CNP group, unlike age, sex, and BMI-matched healthy controls. CNP patients display significant HRV reductions and distinctive qEEG patterns. While healthy controls exhibit significant correlations between parasympathetic HRV parameters and qEEG spectral densities, these relationships are diminished or absent in CNP individuals. LF/HF ratio, reflecting sympathovagal balance, correlates significantly with qEEG frequency bands (theta, alpha, beta), illuminating autonomic dysregulation in CNP. These findings emphasize the intricate brain-heart interplay in chronic pain, warranting further exploration.

What do we know about the role of menopause in cardiovascular autonomic regulation in hypertensive women?

We investigated the systemic arterial hypertension effects on cardiovascular autonomic modulation and baroreflex sensitivity (BRS) in women with or without preserved ovarian function. A total of 120 women were allocated into two groups: middle-aged premenopausal women (42 ± 3 y old; n = 60) and postmenopausal women (57 ± 4 y old; n = 60). Each group was also divided into two smaller groups (n = 30): normotensive and hypertensive. We evaluated hemodynamic and anthropometric parameters, cardiorespiratory fitness, BRS, heart rate variability (HRV), and blood pressure variability. The effects of hypertension and menopause were assessed using a two-way analysis of variance. Post hoc comparisons were performed using the Student-Newman-Keuls test. Comparing premenopausal groups, women with systemic arterial hypertension showed lower BRS (9.1 ± 4.4 vs 13.4 ± 4.2 ms/mm Hg, P < 0.001 ) and HRV total variance (1,451 ± 955 vs 2,483 ± 1,959 ms 2 , P = 0.005) values than normotensive; however, the vagal predominance still remained. On the other hand, both postmenopausal groups showed an expressive reduction in BRS (8.3 ± 4.2 vs 11.3 ± 4.8 ms/mm Hg, P < 0.001) and HRV characterized by sympathetic modulation predominance (low-frequency oscillations; 56% ± 17 vs 44% ± 17, P < 0.001), in addition to a significant increase in blood pressure variability variance (28.4 ± 14.9 vs 22.4 ± 12.5 mm Hg 2 , P = 0.015) compared with premenopausal groups. Comparing both postmenopausal groups, the hypertensive group had significantly lower values ​​of HRV total variance (635 ± 449 vs 2,053 ± 1,720 ms 2 , P < 0.001) and BRS (5.3 ± 2.8 vs 11.3 ± 3.2 ms/mm Hg) than the normotensive. Hypertensive middle-aged premenopausal women present HRV autonomic modulation impairment, but they still maintain a vagal predominance. After menopause, even normotensive women show sympathetic autonomic predominance, which may also be associated with aging. Furthermore, postmenopausal women with hypertension present even worse cardiac autonomic modulation.

Heart rate variability and anthropometric parameters in smok-er’s vs nonsmoker’s status

Abstract: Heart rate variability (HRV) is a simple way to explore autonomic nervous activity. Current studies emphasize the need to identify a dependent relationship between smoking habit and HRV. The findings of these studies could demonstrate that smoking can have both an acute and a chronic effect on HRV. The aim of this study is to investigate the relationship between smoking and anthropometric data such as body weight, body fat distribution and heart rate var-iability. Our study involves measuring HRV parameters at rest and during two tests that are part of the Ewing test battery. Through the obtained data we can demonstrate that active smoking is associated with a reduction in HRV. At the same time, we can state that HRV is affected by dif-ferent behavior patterns of the smoker.complex individualized rehabilitation treatment.

Progressive QTc prolongation and reduced heart rate variability in dementia with Lewy bodies compared to Alzheimer's disease

IntroductionAutonomic dysfunction (AuD) is a significant clinical challenge in patients with Dementia with Lewy Bodies (DLB). Manifestations of AuD such as orthostatic hypotension (OH) is associated with falls and decreased quality of life. Cardiac autonomic denervation is an early phenomenon in DLB and a potential contributor to OH. This retrospective study was undertaken to explore whether routine ECG tracings could be used to identify signs of autonomic dysfunction in DLB. Methods18 patients with DLB and 18 age-matched patients with Alzheimer's disease (AD) were included. ECGs and clinical data were analyzed retrospectively for heart rate variability (HRV) and QTc interval prolongation. ResultsDuring an average of 10 years observation time (first to last ECG recording), the QTc interval increased in the DLB group, but not in the AD group. HRV was significantly lower at end of follow-up in the DLB group than in the AD group. DLB patients with OH had greater QTc prolongation. ConclusionLongitudinal ECG analysis indicates that signs of AuD in DLB are reflected on routine ECG tracings. If confirmed in larger cohorts, this could influence risk stratification and help direct preventive measures.

Prediction model for mild cognitive impairment in patients with type 2 diabetes using the autonomic function test.

Type 2 diabetes mellitus (T2DM) is a risk factor for cognitive impairment, and reduced heart rate variability (HRV) has been correlated with cognitive impairment in elderly individuals. This study investigated risk factors and validated a predictive model for mild cognitive impairment (MCI) in patients with T2DM using an autonomic function test. Patients with T2DM, 50-85years of age, who attended the diabetes clinic at Gyeongsang National University Hospital between March 2018 and December 2019, were included. A total of 201 patients had been screened; we enrolled 124 patients according to the inclusion and exclusion criteria in this study. Cognitive function was assessed using the Montreal Cognitive Assessment-Korean version (MOCA-K); MCI was defined as a total MOCA-K score ≤ 23. Risk factors for MCI in patients with T2DM, including demographic- and diabetes-related factors, and autonomic function test results, were analyzed. Based on multivariate logistic regression, a nomogram was developed as a prediction model for MCI. Thirty-nine of 124 patients were diagnosed with MCI. Age, education, and decreased cardiovagal function were associated with a high risk for MCI, with cardiovagal function exerting the greatest influence. However, diabetes-related factors, such as glycemic control, duration of diabetes, or medications, were not associated with the risk for MCI. The nomogram demonstrated excellent discrimination (area under the curve, 0.832) and was well calibrated. Approximately one-third of patients had MCI; as such, carefully evaluating cognitive function in elderly T2DM patients with reduced HRV is important to prevent progression to dementia.

Heart Rate Variability as a Prognostic Tool for Gastroschisis Infants in the Neonatal Intensive Critical Unit.

Gastroschisis is the most common congenital abdominal wall defect, with an increasing incidence. It results in extrusion of abdominal contents with associated delayed intestinal motility. Abnormal heart rate characteristics (HRCs) such as decreased variability occur due to the inflammatory response to sepsis in preterm infants. This study aimed to test the hypothesis that infants with gastroschisis have decreased heart rate variability (HRV) after birth and that this physiomarker may predict outcomes. We analyzed heart rate data from and clinical variables for all infants admitted with gastroschisis from 2009 to 2020. Forty-seven infants were admitted during the study period and had available data. Complex gastroschisis infants had reduced HRV after birth. For those with sepsis and necrotizing enterocolitis, abnormal HRCs occurred early in the course of illness. Decreased HRV was associated with complex gastroschisis. Infants in this group experienced complications that prolonged time to full enteral feeding and time on total parenteral nutrition. · Infants with gastroschisis can be classified into two subcategories, simple and complex disease.. · Those with complex disease often require prolonged stays in the neonatal intensive care unit and costly hospitalizations. We hypothesized that infants with complex gastroschisis are more likely to have abnormal HRC due to intestinal inflammation.. · In this study, we identified associations between abnormal HRV, heart rate characteristicHRC, and the development of gastroschisis complications. Additionally, we described differences in clinical characteristics between infants with complex versus simple gastroschisis..

Tracking Cancer: Exploring Heart Rate Variability Patterns by Cancer Location and Progression.

Reduced heart rate variability (HRV) is an autonomic nervous system (ANS) response that may indicate dysfunction in the human body. Consistent evidence shows cancer patients elicit lower HRV; however, only select cancer locations were previously evaluated. Thus, the aim of the current study was to explore HRV patterns in patients diagnosed with and in varying stages of the most prevalent cancers. At a single tertiary academic medical center, 798 patients were recruited. HRV was measured via an armband monitor (Warfighter MonitorTM, Tiger Tech Solutions, Inc., Miami, FL, USA) equipped with electrocardiographic capabilities and was recorded for 5 to 7 min with patients seated in an upright position. Three time-domain metrics were calculated: SDNN (standard deviation of the NN interval), rMSSD (the root mean square of successive differences of NN intervals), and the percentage of time in which the change in successive NN intervals exceeds 50ms within a measurement (pNN50). Of the 798 patients, 399 were diagnosed with cancer. Cancer diagnoses were obtained via medical records one week following the measurement. Analysis of variance models were performed comparing the HRV patterns between different cancers, cancer stages (I-IV), and demographic strata. A total of 85% of the cancer patients had breast, gastrointestinal, genitourinary, or respiratory cancer. The cancer patients were compared to a control non-cancer patient population with similar patient size and distributions for sex, age, body mass index, and co-morbidities. For all HRV metrics, non-cancer patients exhibited significantly higher rMSSDs (11.1 to 13.9 ms, p < 0.0001), SDNNs (22.8 to 27.7 ms, p < 0.0001), and pNN50s (6.2 to 8.1%, p < 0.0001) compared to stage I or II cancer patients. This significant trend was consistently observed across each cancer location. Similarly, compared to patients with stage III or IV cancer, non-cancer patients possessed lower HRs (-11.8 to -14.0 bpm, p < 0.0001) and higher rMSSDs (+31.7 to +32.8 ms, p < 0.0001), SDNNs (+45.2 to +45.8 ms), p < 0.0001, and pNN50s (19.2 to 21.6%, p < 0.0001). The HR and HRV patterns observed did not significantly differ between cancer locations (p = 0.96 to 1.00). The depressed HRVs observed uniformly across the most prevalent cancer locations and stages appeared to occur independent of patients' co-morbidities. This finding highlights the potentially effective use of HRV as a non-invasive tool for determining common cancer locations and their respective stages. More studies are needed to delineate the HRV patterns across different ages, between sexes and race/ethnic groups.

Effects of cortisol administration on heart rate variability and functional connectivity across women with different depression histories

Abnormalities within the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system have been implicated in depression. Studies have reported glucocorticoid insensitivity and reduced heart rate variability (HRV) in depressive disorders. However, little is known about the effects of cortisol on HRV and resting-state functional connectivity (rsFC) of the central autonomic network (CAN) in depression. We collected resting-state fMRI and cardiac data for women with different depression histories (n = 61) after administration of cortisol and placebo using a double-blind crossover design. We computed rsFC for R-amygdala and L-amygdala seeds and assessed the change in HRV after cortisol (cortisol-placebo). Analyses examined the effects of acute cortisol administration on HRV and rsFC of the R-amygdala and L-amygdala. There was a significant interaction between HRV and treatment for rsFC between the amygdala and CAN regions. We found lower rsFC between the L-amygdala and putamen for those with a greater decrease in HRV after cortisol. There was also reduced rsFC between the R-amygdala and dorsomedial prefrontal cortex, putamen, middle cingulate cortex, insula, and cerebellum in those with lower HRV after cortisol. These results remained significant after adjusting for depression symptoms, age, and race. Our findings suggest that the effect of cortisol on CAN connectivity is related to its effects on HRV. Overall, these results could inform transdiagnostic interventions targeting HRV and the stress response systems across clinical and non-clinical populations.

Touch as a Stress Buffer? Gender Differences in Subjective and Physiological Responses to Partner and Stranger Touch

AbstractInterpersonal touch buffers against stress under challenging conditions, but this effect depends on familiarity. People benefit from receiving touch from their romantic partners, but the results are less consistent in the context of receiving touch from an opposite-gender stranger. We propose that there may be important gender differences in how people respond to touch from opposite-gender strangers. Specifically, we propose that touch from an opposite-gender stranger may only have stress-buffering effects for men, not women. Stress was induced as participants took part in an emotion recognition task in which they received false failure feedback while being touched by a romantic partner or stranger. We measured subjective and physiological markers of stress (i.e., reduced heart rate variability) throughout the experiment. Neither stranger’s nor partner’s touch had any effect on subjective or physiological markers of stress for men. Women, however, subjectively experienced a stress-buffering effect of partner and stranger touch, but showed increased physiological markers of stress when receiving touch from an opposite-gender stranger. These results highlight the importance of considering gender when investigating touch as a stress buffer.

Do friends get under the skin?: Everyday social encounters and cardiovascular functioning among Black and White adults in the United States.

Studies have shown that contact with friends enhances emotional health, but little is known about whether friends influence cardiovascular health. This study investigated (a) whether encounters with friends and the quality of these encounters were associated with cardiovascular reactivity in everyday life and (b) whether these associations varied by race. Participants were from the Stress and Well-being in Everyday Life Study which included Black (n = 76; aged = 34-76) and White (n = 87, aged = 34-91) adults residing in the United States. Participants provided background and social network information in a baseline interview, followed by a 4-day ecological momentary assessment in which they reported social encounters every 3 hr. Concurrently, participants wore an electrocardiogram monitor which collected physiological data in real time. To assess cardiovascular reactivity, heart rate variability (HRV) was analyzed. Multilevel models revealed that at times when individuals encountered friends (particularly positive encounters), they exhibited a momentary reduction in HRV (within-person association). But those with more friend encounters during the study period (particularly positive encounters) had higher HRV than those with fewer friend encounters during the study period (between-person association). These links were observed only among Black adults, but not among White adults. This study contributes to the conceptual model of social integration and enriches the literature on racial disparities in cardiovascular health from a social perspective. Findings highlight the implications of engagement with friends for momentary cardiovascular reactivity and suggest that friends may be more salient for Black adults' cardiovascular health. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Pre-pregnancy BMI Association with Maternal Phenotype and Offspring Neurobehavioral Outcomes

BackgroundAllostatic load due to chronic exposure to physiological or psychological stressors lead to compromised capacity of the body to maintain homeostasis. Obesity as a metabolic stressor is associated with a suboptimal physiological milieu including an inflammatory state and a dysregulated stress axis. Perinatal maternal body mass index (BMI) impacts pregnancy, birth outcomes, and child metabolic and neurodevelopmental health. We examine the impacts of pre-pregnancy BMI on maternal phenotype characteristics throughout pregnancy and fetal heart rate measurements as an early marker of programming effects of altered autonomic nervous system and infant neurobehavioral outcomes with a focus on sex-dimorphic effects. MethodsPregnant women (n=176) attended sessions at gestation weeks 12-22, 23-28, and 34-36, where blood was collected for cytokine analysis and DNA methylation, and Edinburgh post-partum depression scale was administered. On the latter two visits, heart rate assessment was carried out for mothers and fetuses. ResultsMaternal high BMI was associated with higher perinatal depression, increased inflammation, and reduced heart rate variability. DNA methylation of maternal blood indicated enrichment in immune related biological processes. Moreover, we observed a decrease in fetal heart rate variability in female fetuses of women of high BMI, indicating alteration in the neurobehavioral development of the fetus. In infancy, female infants of high BMI mothers had reduced behavioral regulation and orientation to stimulus. ConclusionThis work highlights that the metabolic stress associated with BMI could leave a molecular fingerprint that could explain other maternal physiological and psychological outcomes, which in turn program the fetal neurodevelopmental outcomes.

Is reduced heart rate variability associated with functional somatic disorders? A cross-sectional population-based study; DanFunD

ObjectivesIt has been hypothesised that functional somatic disorders (FSD) could be initiated by sympathetic predominance in the autonomic nervous system as measured by low heart rate variability (HRV). Earlier studies...

Healthy lifestyle and essential metals attenuated association of polycyclic aromatic hydrocarbons with heart rate variability in coke oven workers

Whether adopting healthy lifestyles and maintaining moderate levels of essential metals could attenuate the reduction of heart rate variability (HRV) related to polycyclic aromatic hydrocarbons (PAHs) exposure are largely unknown. In this study, we measured urinary metals and PAHs as well as HRV, and constructed a healthy lifestyle score in 1267 coke oven workers. Linear regression models were used to explore the association of healthy lifestyle score and essential metals with HRV, and interaction analysis was performed to investigate the potential interaction between healthy lifestyle score, essential metals, and PAHs on HRV. Mean age of the participants was 41.9 years (84.5% male). Per one point higher healthy lifestyle score was associated with a 2.5% (95% CI, 1.0%–3.9%) higher standard deviation of all normal to normal intervals (SDNN), 2.1% (95% CI, 0.5%–3.6%) higher root mean square of successive differences in adjacent NN intervals (r-MSSD), 4.3% (95% CI, 0.4%–8.2%) higher low frequency, 4.4% (95% CI, 0.2%–8.5%) higher high frequency, and 4.4% (95% CI, 1.2%–7.6%) higher total power, respectively. Urinary level of chromium was positively associated with HRV indices, with the corresponding β (95% CI) (%) was 5.17 (2.84, 7.50) for SDNN, 4.29 (1.74, 6.84) for r-MSSD, 12.26 (6.08, 18.45) for low frequency, 12.61 (5.87, 19.36) for high frequency, and 11.31 (6.19, 16.43) for total power. Additionally, a significant interaction was found between healthy lifestyle score and urinary total hydroxynaphthalene on SDNN (Pinteraction = 0.04), and higher level of urinary chromium could attenuate the adverse effect of total hydroxynaphthalene level on HRV (all Pinteraction <0.05). Findings of our study suggest adopting healthy lifestyle and maintaining a relatively high level of chromium might attenuate the reduction of HRV related to total hydroxynaphthalene exposure.

Application of short-term analysis of skin temperature variability in prediction of survival in patients with cirrhosis.

Background: Liver cirrhosis is a complex disorder, involving several different organ systems and physiological network disruption. Various physiological markers have been developed for survival modelling in patients with cirrhosis. Reduction in heart rate variability and skin temperature variability have been shown to predict mortality in cirrhosis, with the potential to aid clinical prognostication. We have recently reported that short-term skin temperature variability analysis can predict survival independently of the severity of liver failure in cirrhosis. However, in previous reports, 24-h skin temperature recordings were used, which are often not feasible in the context of routine clinical practice. The purpose of this study was to determine the shortest length of time from 24-h proximal temperature recordings that can accurately and independently predict 12-month survival post-recording in patients with cirrhosis. Methods: Forty individuals diagnosed with cirrhosis participated in this study and wireless temperature sensors (iButtons) were used to record patients' proximal skin temperature. From 24-h temperature recordings, different length of recordings (30 min, 1, 2, 3 and 6h) were extracted sequentially for temperature variability analysis using the Extended Poincaré plot to quantify both short-term (SD1) and long-term (SD2) variability. These patients were then subsequently followed for a period of 12 months, during which data was gathered concerning any cases of mortality. Results: Cirrhosis was associated with significantly decreased proximal skin temperature fluctuations among individuals who did not survive, across all durations of daytime temperature recordings lasting 1hour or more. Survival analysis showcased 1-h daytime proximal skin temperature time-series to be significant predictors of survival in cirrhosis, whereby SD2, was found to be independent to the Model for End-Stage Liver Disease (MELD) score and thus, the extent of disease severity. As expected, longer durations of time-series were also predictors of mortality for the majority of the temperature variability indices. Conclusion: Crucially, this study suggests that 1-h proximal skin temperature recordings are sufficient in length to accurately predict 12-month survival in patients with cirrhosis, independent from current prognostic indicators used in the clinic such as MELD.

Alleviation of acute stress response by black pepper aroma administration

BackgroundBlack pepper is one of the most popular spices globally. As black pepper essential oil has not yet been used in the context of aromatherapy, this study examined the effect of black pepper aroma on cardiac and peripheral autonomic nervous system (ANS) activity under stressful conditions using an olfactometer to administer aroma in a precise and controlled manner to ensure reproducibility.MethodsA within-participant design experiment was conducted with 20 male university students who performed a 30-min calculation task as a short-term stressor under three aroma conditions: black pepper, ginger, and dipropylene glycol (DPG) (scentless air as a control). Each aroma was sporadically delivered (first 20 s of each 1-min interval) with the olfactometer during the task. Electrocardiograms and skin conductance level (SCL) were measured to evaluate ANS's physiological acute stress response. Subjective evaluations for the given stressful task and impressions on the types of aromas were assessed.ResultsThe physiological acute stress response induced by the short-term stressor, which is characterized by the enhancement of the heart rate (HR) and SCL and decreases in the heart rate variability (HRV), was suppressed with black pepper: the increase in HR and reduction in HRV from the baseline were 38.9% (p = 0.048 when compared with DPG) and 32.9% smaller (p = 0.002 for multiple comparisons) than those in DPG, respectively, and the increase of SCL was 15.5% smaller (p = 0.005 for multiple comparisons) than that in ginger. However, there was no significant difference in subjective scores among the conditions.ConclusionAlthough black pepper is a stimulative agent, the study findings showed that black pepper aroma alleviated the physiological acute stress response, which can be beneficial in aromatherapy under stressful conditions.

Cardiac Autonomic Dysfunction Measured as Reduced Heart Rate Variability, in the Intermediate Post-Covid State in Men

Abstract Background: A critical illness such as severe coronavirus disease 2019 (COVID-19) activates autonomic, endocrine, and emotional stress responses. Whether the manifestations of excessive stress experience persist beyond full recovery into the intermediate post-COVID period (3–6 months after recovery) is not known and was the question we addressed in the current study. Methods: An analytical observational cross-sectional study compared the heart rate variability (HRV), 8 AM serum cortisol concentration, and the Depression, Anxiety, and Stress Scale–21 (DASS-21) scores between COVID-19 recovered participants and their age-matched control subjects (21 male participants, 30–70 years of age, in each group). Results: The median (Q1–Q3) of low frequency (LF), high frequency (HF), and total powers of HRV was significantly reduced in those who recovered from severe COVID-19, compared to control subjects (respectively LF power: 410.871 [245.10–861.94], 947.57 [536.11–1778.55], P = 0.011; HF power: 192.916 [87.66–564.43], 705.18 [248.67–1192.19] P = 0.013; Total power: 646.33 [308.72–1518.28], 1613.33 [956.14–4022.55] P = 0.015, Mann–Whitney U-test). Serum cortisol and DASS-21 scores were not different from the control group. Conclusions: Impaired cardiac autonomic function, evidenced by reduced HRV, was observed in the intermediate period following recovery from severe COVID-19. However, psychological stress and elevated serum cortisol were not noted. Our result that exposes the effect of COVID-19 on cardiac autonomic responsiveness is important as diminished HRV increases the vulnerability of COVID-19 survivors to diseases. These findings may also suggest a focus of therapy in them, as specific interventions are known to improve HRV and cardiac autonomic functioning.

Comparison of time domain indices of heart rate variability between alcohol-dependent individuals and non-alcoholic subjects

Background: Alcohol dependence develops because of repeated alcohol intake. Alcohol damages the cardiac autonomic nerve fibers leading to autonomic imbalance, resulting in reduced heart rate variability (HRV). HRV refers to the complex beat-to-beat variation in the heart rate, produced by the interplay of sympathetic and parasympathetic neural activity at the Sino-atrial node. Our body works effectively in parasympathetic activity dominance. The time domain indices of HRV are specific markers of parasympathetic activity. A decrease in the time domain parameters indicates reduced parasympathetic activity in the heart, indicating cardiac autonomic dysfunction with vagal neuropathy. Aims and Objectives: The objectives of the study are as follows: (1) To assess the HRV in alcohol-dependent individuals using time domain indices. (2) To compare the HRV between alcoholic-dependent individuals and non-alcoholic subjects. Materials and Methods: A total of 110 individuals in the age group of 20–55 years were recruited for our study. Among them, 55 were alcohol-dependent individuals selected based on the diagnostic and statistical manual-IV, international classification of diseases-10 criteria, and 55 age and gender-matched volunteers were selected as healthy non-alcoholic controls. Short-term HRV was recorded in a supine posture, and the results were interpreted. Statistical analysis was done using the software SPSS version 21.0. Results: Our results showed a significant reduction in the time-domain parameters of HRV – SDNN, RMSSD, NN50, and pNN50 in the alcohol-dependent individuals compared to the controls, suggesting reduced parasympathetic activity in the heart indicating cardiac autonomic neuropathy. Conclusion: Alcohol affects the cardiac autonomic status leading to sudden death due to arrhythmias. HRV can be used as a non-invasive test to assess cardiac autonomic dysfunction and its biofeedback can help alcohol-dependent individuals to adopt healthy lifestyle measures.

Heart rate variability is reduced in COVID-19 survivors and associated with physical activity and fatigue.

Reduced heart rate variability (HRV) and fatigue are common after COVID-19 infection and both are potentially influenced by physical activity (PA). We compared resting HRV, PA from accelerometers and questionnaires, and self-reported fatigue in 41 COVID-19 survivors (~8 months postinfection, 38 ± 17 years) with 41 matched controls. Differences in HRV were observed on acceleration capacity (p = 0.041), deceleration capacity (p = 0.032), high-frequency peak frequency (p = 0.019), absolute low-frequency power (p = 0.042), relative very low-frequency power (p = 0.012), SD2 (from Poincare plot; p = 0.047), and DFA2 (slope of long-term detrended fluctuation analysis; p = 0.004). Fatigue was greater in COVID-19 survivors (p < 0.001) with no differences in PA. Moderate-vigorous physical activity (MVPA) (Standardized Beta = -0.427, p = 0.003) and steps per day (Standardized Beta = -0.402, p = 0.007) were associated with DFA2 in COVID-19 survivors after controlling for age, sex, and body fat percentage. Fatigue was correlated to less MVPA (Spearman's rho = 0.342, p = 0.031) and fewer steps per day (rho = 0.329, p = 0.038) in COVID-19 survivors, and was indirectly linked to HRV through these PA mediators (Estimate = -0.20; p = 0.040). We present a model showing the complex relations between HRV, PA, and fatigue that provides the foundation for strategies to improve outcomes and rehabilitation after COVID-19 infection.

Disinhibited or Disconnected? Dietary Restraint Attenuates the Relationship Between Heart Rate Variability and Stress-Induced Suppression of Food Intake

Abstract: Literature on restrained eaters posits that the capacity to successfully diet is cognitively demanding, requiring exertion of cognitive control over one’s eating behaviour. Demands that deplete this limited inner resource can thus lead restrained eaters to become disinhibited and consume large amounts of food. Although self-regulation is inferred to play a role, it has not yet been studied in combination with its physiological correlates. As low heart rate variability (HRV) is associated with lower self-regulatory capacity, and acute mental stressors decrease HRV, it was hypothesized that reduced HRV during stress may mediate the relationship between stress and food intake, and that the mediation may be moderated by dietary restraint. Specifically, the moderation hypothesis predicted more restrained eaters would exhibit a stronger relationship between low HRV and intake. Female undergraduates ( n = 92) were randomized to a stress or control condition while HRV was recorded. Participants subsequently engaged in a bogus taste test to quantify post-stress consumption. Restraint was conceptualized using Hagan and colleagues’ (2017) latent restraint factors. A significant moderated mediation emerged for Weight-Focused Restraint, ab3 = .196, SE = .077, 95% CI [.060, .361] and Calorie Counting, ab3 = .062, SE = .023, 95% CI [.024, .115]. However, contrary to expectation, stress-induced HRV reduction was associated with decreased intake for those low in restraint, whereas intake was unrelated to HRV for individuals with higher dietary restraint. Further, there was no evidence of traditionally-defined disinhibition in more restrained eaters. Results suggest those with higher restraint show a relative disconnection from internal physiological cues shown to affect intake under stress in less restrained individuals.

Cardiac Abnormalities in Refractory Status Epilepticus-an Exploratory Study.

Cardiac abnormalities have been reported during ongoing seizures and refractory status epilepticus (RSE). Reduced heart rate variability (HRV) and cardiac arrhythmias may contribute to sudden unexpected death in epilepsy. We sought to explore the utility of electrocardiographic and echocardiographic changes in patients with RSE prognosis and functional outcome. Patients of RSE underwent electrocardiogram (ECG), holter, troponin-I (Trop I), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and 2-dimensional echocardiogram (2D Echo) along with continuous electroencephalogram in first 24 hours and admission. Heart rate changes/arrhythmias, corrected QT interval (QTc) and HRV, ventricular dysfunction or regional motion wall abnormality were studied on 2D Echo. These parameters were also at baseline, at discharge or death and 30 days post discharge. This prospective observational study conducted over 18 months enrolled 20 patients with RSE, fulfilling the inclusion criteria. Mean age was 47.75±17.2 years with male: female ratio of 1:1. Mean time to presentation from seizure onset was 8.80±7.024 hours. Central nervous system infection (35.0%), autoimmune encephalitis (20.0%) and cerebrovascular disease (20.0%) were the common etiologies. Amongst cardiac injury markers, cardiac enzymes and QTc prolongation were the commonest abnormalities in RSE. Both reduced HRV and presence of cardiac injury markers had significant correlation with poor outcome along with poor Glasgow coma scale (GCS) and modified Rankin scale (mRS) at presentation, and presence of non convulsive status epilepticus (NCSE). Presence of poor GCS, poor mRS, markers of cardiac injury, reduced HRV and occurrence of NCSE have a consistent correlation with mortality and poor clinical outcome. Therefore, routine assessment of cardiac abnormalities using affordable, easily accessible and non-invasive tools such as ECG, 2D Echo, holter NT-proBNP and Trop I is recommended in RSE patients.