Spa therapy is recommended to manage symptoms of fibromyalgia, but the physiological mechanisms underlying this improvement have been poorly studied. In an original study, we explored the effect of a 3-week rheumatology spa treatment for fibromyalgia patients on quality of life and with a symptom severity questionnaire. We present here the results of an ancillary study which explored three secondary criteria using objective measurement methods: diurnal actimetry for physical activity analysis, nocturnal actimetry for sleep analysis and heart rate variability. Eighty-three fibromyalgia patients were randomized to participate in an immediate 3-week rheumatological spa therapy, either a start within 6 weeks after inclusion (interventional group, n = 39) or a delayed, start 6 months after inclusion (control group, n = 44). Patients were asked to wear an actimeter (n = 56) to assess diurnal physical activity and sleep quality and a 24-h Holter ECG (n = 60) to assess nocturnal heart rate variability at baseline, 3 months and 6 months after inclusion. Time spent in sedentary and light physical activity was reduced to ∼30 min at 6 months in the interventional group (P = 0.027). Sleep quality and heart rate variability were not improved. Spa therapy made it possible to reduce sedentary activities in patients\' daily life for up to 6 months afterwards, concomitant with the improvement in quality of life, pain and fatigue as highlighted in the original Thermalgi study.

Stressful situations lead to change in or damage to the central nervous system, the hypothalamic-pituitary-adrenal axis, and autonomic function. Techniques for reducing stress such as yoga and mindfulness meditation have been reported to improve emotional regulation and mindfulness skill, as well as stress response. Mindfulness skill relies on intense focus to quiet the mind and bring concentration to the present moment. The present study was a randomized control trial to investigate the effects of an 8-week training program (three 45-minute sessions/week, one session with an instructor and two sessions as home practice) in mindfulness meditation or in yoga on stress and related variables in healthy people. Forty-four healthy participants were randomly allocated to one of three groups: a mindfulness group (n = 16), a yoga group (n = 13), and a control group (n = 15). The yoga training significantly modified heart rate variability, contributing to decreased relative power of the low-frequency band; the relative power of the high-frequency band increased after training. The mindfulness meditation training significantly improved mindfulness skill and concentration performance. In the present study, yoga was associated with increased heart rate variability and mindfulness meditation was associated with an increase in mindfulness skill and concentration performance.

UNASSIGNED: Heart rate variability biofeedback (HRVB) is a well-studied intervention known for its positive effects on emotional, cognitive, and physiological well-being, including relief from depressive symptoms. However, its practical use is hampered by high costs and a lack of trained professionals. Smartphone-based HRVB, which eliminates the need for external devices, offers a promising alternative, albeit with limited research. Additionally, premenstrual symptoms are highly prevalent among menstruating individuals, and there is a need for low-cost, accessible interventions with minimal side effects. With this pilot study, we aim to test, for the first time, the influence of smartphone-based HRVB on depressive and premenstrual symptoms, as well as anxiety/stress symptoms and attentional control.
UNASSIGNED: Twenty-seven participants with above-average premenstrual or depressive symptoms underwent a 4-week photoplethysmography smartphone-based HRVB intervention using a waitlist-control design. Laboratory sessions were conducted before and after the intervention, spaced exactly 4 weeks apart. Assessments included resting vagally mediated heart rate variability (vmHRV), attentional control via the revised attention network test (ANT-R), depressive symptoms assessed with the BDI-II questionnaire, and stress/anxiety symptoms measured using the DASS questionnaire. Premenstrual symptomatology was recorded through the PAF questionnaire if applicable. Data analysis employed linear mixed models.
UNASSIGNED: We observed improvements in premenstrual, depressive, and anxiety/stress symptoms, as well as the Executive Functioning Score of the ANT-R during the intervention period but not during the waitlist phase. However, we did not find significant changes in vmHRV or the Orienting Score of the ANT-R.
UNASSIGNED: These findings are promising, both in terms of the effectiveness of smartphone-based HRVB and its potential to alleviate premenstrual symptoms. Nevertheless, to provide a solid recommendation regarding the use of HRVB for improving premenstrual symptoms, further research with a larger sample size is needed to replicate these effects.

BACKGROUND: Bradycardia and dysautonomia observed during SARS-Cov2 infection suggests involvement of the autonomic nervous system (ANS). Limited data exists on ANS dysregulation and its association with outcomes in patients with acute respiratory distress syndrome (ARDS) related to COVID-19 (C-ARDS) or other etiologies (NC-ARDS).
OBJECTIVE: We aimed to explore sympathovagal balance, assessed by heart rate variability (HRV), and its clinical prognostic value in C-ARDS compared with NC-ARDS.
METHODS: A single-center, prospective case-control study was conducted. Consecutive patients meeting ARDS criteria between 2020 and 2022 were included. HRV was assessed using 1-hour electrographic tracing during a stable, daytime period.
RESULTS: Twenty-four patients with C-ARDS and 19 with NC-ARDS were included. Age, sex and ARDS severity were similar between groups. The median heart rate was markedly lower in the C-ARDS group than in the NC-ARDS group (60 [53-72] versus 101 [91-112] bpm, p<.001). Most of HRV parameters were significantly increased in patients with C-ARDS. HRV correlated with heart rate only in patients with C-ARDS. A positive correlation was found between the low-to high-frequency ratio (LF/HF) and length of intensive care unit stay (r = 0.576, p<.001).
CONCLUSIONS: This study confirmed that C-ARDS was associated with marked bradycardia and severe ANS impairment, suggesting a sympathovagal imbalance with vagal overtone. Poor outcomes appeared to be more related to sympathetic rather than parasympathetic hyperactivation.

BACKGROUND: Imagery rescripting (ImRs) is a psychotherapeutic intervention targeting aversive memories. During the three-phase intervention, patients reexperience their aversive memory (phase 1), observe the scene from their adult perspective, and intervene to help their former selves (phase 2), and reexperience it again with the positive changes (phase 3). Previous studies have rarely investigated emotional and regulatory processes taking place during the intervention.
OBJECTIVE: This randomized controlled trial investigated self-reported affective and physiological responses during ImRs.
METHODS: Seventy-seven patients with social anxiety disorder (SAD) were randomly assigned to a single session of ImRs or a control intervention (recall and discussion of the memory) targeting an aversive social memory. Heart rate (HR) and heart rate variability (HRV) were assessed during and post hoc ratings of positive and negative feelings after baseline and the intervention phases.
RESULTS: Relative to the control intervention, ImRs resulted in an initial increase in negative feelings from baseline to phase 1 and a following larger (phase 1 to phase 2) and more stable (phase 2 to phase 3) decrease in negative feelings/increase in positive feelings. On the physiological level, during ImRs compared to the control intervention, mean HR was significantly higher during phase 1 and HRV during phase 3, each compared to baseline.
CONCLUSIONS: These results provide further information about the specific sequence of emotional responses on different response levels during ImRs, being consistent with known theories of emotional processing and supposed mechanisms of ImRs.

OBJECTIVE: A temporal reduction in the cardiovascular autonomic responses predisposes patients to cardiovascular instability after a viral infection and therefore increases the risk of associated complications. These findings have not been replicated in a bacterial infection. This pilot study will explore the prevalence of cardiovascular autonomic dysfunction (CAD) in hospitalized patients with a bacterial infection.
METHODS: A longitudinal observational pilot study was conducted. Fifty participants were included: 13 and 37 participants in the infection group and healthy group, respectively. Recruitment and data collection were carried out during a two-year period. Participants were followed up for 6 weeks: all participants\' cardiovascular function was assessed at baseline (week 1) and reassessed subsequently at week 6 so that the progression of the autonomic function could be evaluated over that period of time. The collected data were thereafter analyzed using STATA/SE version 16.1 (StataCorp). The Fisher Exact test, McNemar exact test, Mann-Whitney test and Wilcoxon test were used for data analysis.
RESULTS: 32.4% of the participants in the healthy group were males (n = 12) and 67.6% were females (n = 25). Participants\' age ranged from 33 years old to 76 years old with the majority being 40-60 years of age (62.1%) (Mean age 52.4 SD = 11.4). Heart rate variability (HRV) in response to Valsalva Maneuver, metronome breathing, standing and sustained handgrip in the infection group was lower than in the healthy group throughout the weeks. Moreover, both the HRV in response to metronome breathing and standing up showed a statistically significant difference when the mean values were compared between both groups in week 1 (p = 0.03 and p = 0.013). The prevalence of CAD was significantly higher in the infection group compared to healthy volunteers, both at the beginning of the study (p = 0.018) and at the end of follow up (p = 0.057), when all patients had been discharged.
CONCLUSIONS: CAD, as assessed by the HRV, is a common finding during the recovery period of a bacterial infection, even after 6 weeks post-hospital admission. This may increase the risk of complications and cardiovascular instability. It may therefore be of value to conduct a wider scale study to further evaluate this aspect so recommendations can be made for the cardiovascular autonomic assessment of patients while they are recovering from a bacterial infectious process.

Studies have shown a significant association between effective parasympathetic modulation of the heart and processes linked to social cognition. Particularly, Quintana and colleagues documented a relation between vagally-mediated heart rate variability (vmHRV) and performance on a theory of mind (ToM) task, namely, the Reading the Mind in the Eyes Test (RMET), in a sample of university students. The purpose of the present study was to test whether such result would extend to a sample of school-aged children (7-9 years old) using the child version of the RMET. In addition, the Eyes Test Revised was administered as it is more suitable to evaluate ToM during childhood. Results supported the positive association between vmHRV and ToM abilities, replicating and extending previous results obtained in young adults. The current study adds to the existing literature pointing to HRV as a putative biomarker of social cognition abilities.

OBJECTIVE: To investigate how a change in body position with light-intensity physical activity (PA) \'snacks\' (LIPAS, alternate sitting and standing, walking or standing continuously) compared with uninterrupted prolonged sitting affects glucose metabolism and heart rate variability (HRV) parameters in young adults with overweight and obesity.
METHODS: We conducted a four-arm randomized controlled crossover trial. The following conditions were tested during an 8-h simulated workday: uninterrupted prolonged sitting (SIT), alternate sitting and standing (SIT-STAND; 2.5 h total), continuous standing (STAND), and continuous walking (1.0 mph; WALK). The primary outcome was to investigate how a change in body position (alternate sitting and standing, walking or standing continuously) compared with uninterrupted sitting affects mean 8-h glucose metabolism. Secondary outcomes included the effects on 2-h postprandial glucose concentrations, as well as on 8-h/24-h heart rate and HRV parameters, in the respective study arms. Capillary blood samples were drawn from an hyperemised earlobe in the fasted state and once every hour during each trial intervention by puncturing the earlobe with a lancet and collecting 20 μL of blood (Biosen S-Line Lab+; EKF diagnostics, Barleben, Germany). HRV was assessed for 24 h including the 8-h intervention phase, and a home phase by means of a Holter electrocardiogram. All participants received the same standardized non-relativised breakfast and lunch during the four trial visits.
RESULTS: Seventeen individuals (eight women, mean age 23.4 ± 3.3 years, body mass index 29.7 ± 3.8 kg/m2, glycated haemoglobin level 34.8 ± 3.1 mmol/mol [5.4 ± 0.3%], body fat 31.8 ± 8.2%) completed all four trial arms. Compared with SIT (89.4 ± 6.8 mg/dL), 8-h mean glucose was lower in all other conditions (p < 0.05) and this was statistically significant compared with WALK (86.3 ± 5.2 mg/dL; p = 0.034). Two-hour postprandial glucose after breakfast was approximately 7% lower for WALK compared with SIT (p = 0.002). Furthermore, significant time × condition effects on HRV parameters favouring light-intensity walking were observed (p < 0.001).
CONCLUSIONS: Replacement and interruption of prolonged sitting with light-intensity walking showed a significant blood glucose-lowering effect and improved HRV during an 8-h work environment in young adults with overweight and obesity.

The purpose of the present cross-sectional study was to examine the relationship between heart rate variability (HRV) and the range of cervical motion, disability, pain intensity, pain catastrophizing, and quality of life in patients with chronic, non-specific neck pain. Thirty-five patients, aged 20-48 years, with chronic non-specific neck pain, completed validated questionnaires regarding neck pain intensity, pain-associated disability, catastrophic thoughts, and quality of life. The range of cervical motion was assessed using a digital goniometer. HRV indices were recorded in three positions (supine, sitting, and standing) through a smartphone application. Several significant correlations were observed between HRV indices and neck pain disability, the helplessness factor of catastrophizing, neck rotation, and quality of life. These correlations were only observed in the standing position. Pain catastrophizing was positively correlated with disability and pain intensity during active neck movement (Pearson r = 0.544, p < 0.01; Pearson r = 0.605, p < 0.01, respectively). Quality of life was negatively correlated with pain intensity during active movement (Pearson r = -0.347, p < 0.05). HRV indices were correlated with the psychological and physical domains of neck pain. These cardiac indices have been related to neck pain variables in some previous studies. Further research is needed to confirm this relationship in different daily conditions.

Heart rate variability biofeedback (HRVBF) is a promising anxiety-reducing intervention that increases vagally-mediated heart rate variability (vmHRV) through slow-paced breathing and feedback of heart rhythm. Several studies have reported the anxiety-reducing effects of HRVBF; however, some studies have reported such training as ineffective. Furthermore, the effects of training and underlying brain activity changes remain unclear. This study examined the anxiety-reducing effects of HRVBF training and related brain activity changes by randomly assigning participants, employing an active control group, and measuring anxiety-related attentional bias using the emotional Stroop task and electroencephalography (EEG). Fifty-five healthy students with anxiety were randomly assigned to the HRVBF or control groups, and 21 in the HRVBF group and 19 in the control group were included in the analysis. Both groups performed 10 training sessions of 20 min each within 3 weeks. They were assessed using resting vmHRV, event-related potential (ERP), time-frequency EEG, attentional bias, and the State-Trait Anxiety Inventory-JYZ (STAI-JYZ) before and after training. The results demonstrated increased resting vmHRV in the HRVBF group compared to the control group after training. However, no differences were observed in ERP, time-frequency EEG, attentional bias, and STAI-JYZ. Participants with higher pre-training resting vmHRV achieved higher heart rhythm coherence in HRVBF training and had reduced attentional bias. This study suggests that individuals with higher resting vmHRV are more likely to be proficient in HRVBF training and benefit from its anxiety-reducing effects. The findings contribute to participant selection to benefit from HRVBF training and modification of the training protocols for non-responders.Clinical trial registrationOrganization: University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR), JapanRegistration number: UMIN000047096Registration date: March 6, 2022.