Heart Rate Variability Measures Research Articles

Examining the practical importance of nonstationary cardio-respiratory coupling detection in breathing training: a methodological appraisal

This study investigates changes in cardiorespiratory coupling during clinic breathing training and its impact on autonomic nervous functioning compared with heart rate variability (HRV). A total of 39 subjects undergoing dynamic electrocardiogram-recorded breathing training were analyzed. Subjects were divided into early- and late-training periods, and further categorized based on changes in HRV indexes. Subtypes were identified using time-frequency cardiorespiratory coupling diagrams. Significant differences were observed in the high-frequency (HF) index between training stages in the subgroup with increasing HF-HRV (p = 0.0335). Both unimodal and bimodal subtypes showed significant high-frequency coupling (HFC) in the mid-training period compared with early and late stages (both p < 0.0001), suggesting improved parasympathetic cardiac regulation or reduced sympathetic control. This study highlights the potential of nonstationary cardiorespiratory coupling analysis alongside traditional HRV in evaluating the therapeutic effect of breathing training on autonomic nervous function. Cardiorespiratory coupling analysis could provide valuable adjunctive information to HRV measures for assessing the impact of breathing training.

Cardiovascular responses as predictors of mortality in children with acute brain injury.

Investigate the utility of cardiovascular responses such as heart rate (HR), blood pressure (BP), and heart rate variability (HRV) in the prognosis of children with acute acquired brain injury (ABI). Children under 18 years with severe acute acquired brain injury (ABI) who survived at least 12 h after PICU admission were included in a prospective observational cohort in a tertiary academic PICU. Physiological variables, neurological data, laboratory tests (chemistry and hematology), and medications were recorded within 12 h of admission. Linear and nonlinear HRV indices, CT scans, PICU scores, and survival rates were evaluated. Seventy-two children, median age 10.7 years (IQR 4.1-13.6), were eligible for the study; 28 (38.9%) were diagnosed with brain death (BD). Tachycardia, SBP and MBP < 5th percentile, and MBP and DBP> 99th percentile were significantly associated with mortality. Poincaré SD1/SD2 was significantly associated with mortality after adjusting for age, sex and ongoing medication. Tachycardia, systolic hypotension and median hypo and hypertension were associated to mortality in children with severe ABI. While further validation through larger, multicenter studies is necessary, the Poincaré SD1/SD2 ratio has shown promise as a prognostic tool for predicting mortality in children with severe ABI. This study explores cardiovascular changes, including heart rate and blood pressure, and linear/nonlinear HRV measures using ECG at 1000 Hz, and compare them with other prognostic factors like brain tomography and PICU scores. Tachycardia, hypo/hypertension in the early hours after admission are linked to early mortality in children with severe traumatic and non-traumatic brain injury. Linear/non-linear measures of HRV were also related to survival. Higher HRV values indicating better survival chances. We identified Poincaré SD1/SD2 ratio as a promising tool for predicting mortality in children with severe ABI.

Influence of an inspiratory muscle fatigue protocol on older adults on respiratory muscle strength and heart rate variability. A randomized controlled trial

IntroductionInspiratory muscle fatigue has been shown to have effects on the autonomic nervous system and physical condition. This study aimed to evaluate the influence of an inspiratory muscle fatigue protocol on respiratory muscle strength and heart rate variability in older adults.Materials and methodsA randomized controlled clinical trial with double-blinding was carried out involving 24 individuals over 60 years old who demonstrated physical independence in walking and movement. Participants were distributed randomly into three groups: Inspiratory muscle fatigue, activation and control. Measurements of heart rate variability, diaphragmatic ultrasound, and maximum inspiratory pressure were taken at two stages: prior to the intervention (T1) and directly after treatment (T2).ResultsThe inspiratory muscle fatigue group exhibited decrease scores in respiratory and heart rate variability subsequent to undergoing the diaphragmatic fatigue intervention compared to both the activation and control groups (p &amp;lt; 0.05). Conversely, the activation group demonstrated higher values in heart rate variability and respiratory capacity variables following the inspiratory muscle activation training (p &amp;lt; 0.05).ConclusionsFatigue of the inspiratory musculature appears to negatively impact heart rate variability and inspiratory muscle strength in older adults.Clinical trial registrationhttps://clinicaltrials.gov/study/NCT06269042, identifier: NCT06269042.

Is Greener Better? Quantifying the Impact of a Nature Walk on Stress Reduction Using HRV and Saliva Cortisol Biomarkers

The physiological impact of walking in nature was quantified via continuous heart rate variability (HRV), pre- and post-walk saliva cortisol measures, and self-reported mood and mindfulness scores for N = 17 participants who walked “The Green Road” at Walter Reed National Military Medical Center in Bethesda, Maryland. For N = 15 of the participants, HRV analysis revealed two main groups: group one individuals had a 104% increase (mean) in the root mean square standard deviation (RMSSD) and a 47% increase (mean) in the standard deviation of NN values (SDNN), indicating an overall reduction in physiological stress from walking the Green Road, and group two individuals had a decrease (mean) of 42% and 31% in these respective HRV metrics, signaling an increase in physiological stresses. Post-walk self-reported scores for vigor and mood disturbance were more robust for the Green Road than for a comparable urban road corridor and showed that a higher HRV during the walk was associated with improved overall mood. Saliva cortisol was lower after taking a walk for all participants, and it showed that walking the Green Road elicited a significantly larger reduction in cortisol of 53%, on average, when compared with 37% of walking along an urban road. It was also observed that the order in which individuals walked the Green Road and urban road also impacted their cortisol responses, with those walking the urban road before the Green Road showing a substantial reduction in cortisol, suggesting a possible attenuation effect of walking the Green Road first. These findings provide quantitative data demonstrating the stress-reducing effects of being in nature, thus supporting the health benefit value of providing access to nature more broadly in many settings.

Applying an osteopathic intervention to improve mild to moderate mental health symptoms: a mixed-methods feasibility randomised trial.

The increasing prevalence of mental health disorders in the United Kingdom necessitates the exploration of novel treatment modalities. This study aimed to assess the feasibility and acceptability of conducting a randomised controlled trial (RCT) evaluating the efficacy of four osteopathic interventions on psychophysiological and mental health outcomes. A mixed-methods feasibility study with an explanatory sequential design was implemented. The quantitative phase involved randomising 42 participants into four intervention groups: (1) high-velocity and articulation techniques (HVAT), (2) soft-tissue massage (STM), (3) craniosacral therapy (CST), and (4) a combination approach. Primary outcome measures encompassed recruitment rate, assessment duration, questionnaire completion, intervention attrition, and adverse events. Secondary outcomes included validated assessments of depression, anxiety, stress, psychological flexibility, heart rate variability (HRV), and interoception, administered pre- and post-intervention. Analysis of variance (ANOVA) was employed to evaluate pre-post intervention changes. The qualitative phase comprised semi-structured interviews analysed using thematic analysis. The study achieved a recruitment rate of 21 eligible participants per month, with 54.8% of respondents meeting eligibility criteria. All 33 participants who completed the study underwent interventions and assessments within the allocated one-hour timeframe, with full questionnaire completion. The attrition rate was 21%. No adverse events were reported. Qualitative analysis revealed positive participant experiences, with themes highlighting good practitioner communication, intervention accessibility, and increased bodily awareness. Some participants found the questionnaire battery burdensome. Exploratory quantitative analyses showed variations in effects across interventions for heart rate variability, interoceptive accuracy, and mental health measures, but these results should be interpreted cautiously due to the small sample size. This study provides evidence supporting the feasibility and acceptability of a larger-scale RCT investigating osteopathic interventions for individuals presenting with mild psychological symptoms. The preliminary findings suggest potential efficacy in improving mental health outcomes, warranting further investigation. Trial registration NCT05674071, registered 06/01/2023.

Attentional focus modulates physiological response to arousal in a competitive putting task.

Attentional focus during the execution of perceptual motor tasks has been shown to affect performance outcomes. The purpose of this study is to assess the physiological changes prompted by attentional focus in various levels of stress. Thirty-six healthy young males and females were randomized into groups and directed on attentional focus in a staged putting competition scenario intended to elicit competitive anxiety. External focus groups experienced less internal workload at all arousal levels and preserved heart rate variability measures when audiovisual distraction was introduced.

Relationship between heart rate variability and echocardiography indices of cardiac function in healthy individuals.

This study evaluated the relationship between HRV and echocardiography indices of cardiac function. Healthy individuals (N = 30) aged 33 ± 10 years old, underwent short-term resting HRV assessment and transthoracic echocardiography with speckle tracking analysis. Time domain - (i.e. R-R interval, root mean square of successive RR interval difference (RMSSD), standard deviation of normal RR intervals (SDNN) and frequency domain-measures of HRV (i.e. high-frequency power (HF), low-frequency power (LF), high-frequency normalised (HFnorm) and low-frequency normalised (LFnorm)). Echocardiography indices of cardiac function included; Left ventricular ejection fraction (LVEF), left- and right-ventricular global longitudinal strain (LV-GLS, and RV GLS), left atrial strain: left atrial reservoir (LAres), left atrial conduit (LAcon) and left atrial contraction (LACT). The mean values for HRV time-domain measures were: R-R (991 ± 176 ms), SDNN (50.9 ± 21.5 ms), and RMSSD (46.8 ± 29.4 ms); and frequency-domain: LF (727 ± 606 ms2), HF (415 ± 35 ms2), LFnorm (56 ± 19.4) and HFnorm (36.5 ± 18.8). Mean values for indices of cardiac function were LVEF (59.9% ± 2.8%), LV-GLS (19.2% ± 1.4%), RV-GLS (21.7% ± 2.7%), LAres (36.8% ± 6.99%), LAcon (26.2% ± 6.95%) and LACT (12.3% ± 3.56%). There was a significant negative relationship between HF and LV-GLS (r = -0.47, p = 0.01) and RMSSD and LVEF (r = -0.39, p = 0.03) respectively. Heart rate variability measures such as high frequency power and RMSSD are associated with left ventricle systolic function in healthy individuals.

The behavioral and physiological correlates of affective mood switching in premenstrual dysphoric disorder.

Premenstrual dysphoric disorder (PMDD), a more severe manifestation of premenstrual syndrome (PMS), is characterized by emotional, behavioral, and physical symptoms that begin in the mid-to-late luteal phase of the menstrual cycle, when estradiol and progesterone levels precipitously decline, and remit after the onset of menses. Remotely monitoring physiologic variables associated with PMDD depression symptoms, such as heart rate variability (HRV), sleep, and physical activity, holds promise for developing an affective state prediction model. Switching into and out of depressive states is associated with an increased risk of suicide, and therefore, monitoring periods of affective switching may help mitigate risk. Management of other chronic health conditions, including cardiovascular disease and diabetes, has benefited from remote digital monitoring paradigms that enable patients and physicians to monitor symptoms in real-time and make behavioral and medication adjustments. PMDD is a chronic condition that may benefit from real-time, remote monitoring. However, clinical practice has not advanced to monitoring affective states in real-time. Identifying remote monitoring paradigms that can detect within-person affective state change may help facilitate later research on timely and efficacious interventions for individuals with PMDD. This narrative review synthesizes the current literature on behavioral and physiological correlates of PMDD suitable for remote monitoring during the menstrual cycle. The reliable measurement of heart rate variability (HRV), sleep, and physical activity, with existing wearable technology, suggests the potential of a remote monitoring paradigm in PMDD and other depressive disorders.

Inter- and intra-examiner reliability of short-term measurement of heart rate variability on rest in patients hospitalized with COVID-19

Measures reflecting cardiac sympathovagal activity, particularly those associated with heart rate variability (HRV), are widely recognized and utilized in both scientific and clinical contexts. This study aimed to assess the inter- and intra-examiner reliability of short-term HRV parameters in patients hospitalized with coronavirus disease 2019 (COVID-19). A total of 103 patients (both sexes) diagnosed with COVID-19 were included in the study. HRV was analyzed using both linear and nonlinear methods. Reliability was evaluated through intraclass correlation coefficient (ICC2.1), minimum detectable change (MDC), standard error of measurement (SEM), and coefficient of variation (CV). According to Fleiss’ criteria, excellent reliability was demonstrated, with ICC values ranging from 0.970 to 0.999 for Examiner 1, and from 0.956 to 0.999, for Examiner 2. In the inter-examiner analysis, the ICCs of HRV parameters ranged from 0.972 to 0.999. SEM values for intra-examiner reliability for Examiner 1 ranged from 0.02 to 5.64, with MDC values from 0.05 to 15.64, and CV (%) from 0.28 to 8.04. For Examiner 2, SEM values ranged from 0.02 to 8.18, MDC values from 0.05 to 22.68, and CV (%) from 0.24 to 8.14. For inter-examiner reliability, SEM values ranged from 0.02 to 6.17, MDC from 0.06 to 17.11, and CV (%) from 0.34 to 9.81. Across all analyses, CVs for HRV parameters remained below 10%. Considering different time points and different examiners, short-term resting HRV measurements in patients hospitalized with COVID-19, as evaluated using a portable heart rate device, exhibit high reliability.

Heart Rate Variability in Basketball: The Golden Nugget of Holistic Adaptation?

The main aim of this narrative review is to assess the existing body of scientific literature on heart rate variability (HRV) in relation to basketball, focusing on its use as a measure of internal load and vagal nerve responses. Monitoring HRV offers insights into the autonomic function and training-induced adaptations of basketball players. Various HRV measurement protocols, ranging from short-term to longer durations, can be conducted in different positions and conditions, such as rest, training, and sleep, to determine this key metric. Consistency and individualization in measurement protocols, responding to the athlete’s specific characteristics, is crucial for reliable HRV data and their interpretation. Studies on HRV in basketball have explored psychological adaptation, training effects, individual differences, recovery, and sleep quality. Biofeedback techniques show positive effects on HRV and anxiety reduction, potentially enhancing performance and stress management. The scientific literature on HRV in basketball could benefit from studies involving longer monitoring periods to identify significant trends and results related to training and recovery. Longitudinal HRV monitoring in teams with intense travel schedules could reveal the impact on athletes of all levels and ages, and, in this regard, individualized interpretation, considering the subjective recovery and fitness levels of athletes, is recommended to optimize training programs and performance. HRV provides insights into training and competitive loads, aiding in determining exercise intensities and training status. Additionally, HRV is linked to recovery and sleep quality, offering valuable information for optimizing player performance and well-being. Overall, HRV is a reliable tool for adjusting training programs to meet the specific needs of basketball players.

Дослідження впливу фаз менструального циклу на функціональний стан кваліфікованої ветеранки спорту з дзюдо

Purpose: to investigate the influence of menstrual cycle phases on the functional status of a qualified female veteran judo athlete. Material and methods. The following methods were used in the study: analysis of scientific and methodological information and Internet sources; generalization of advanced practical experience; measurement of sensorimotor reactions and determination of heart rate variability indices; methods of mathematical statistics. A qualified veteran female judo athlete (Master of Sports of Ukraine) in the age category F2 (1983-1979) took part in the study. We performed 84 measurements of heart rate variability (n=42, HRV in the supine position; n=42, heart rate variability during the test task dedicated to measuring the choice reaction). The measurement was performed using two computer programs for mobile devices running iPadOS «Research HRV» and «HRV SR+CR» during morning hours (7-8 hours) and afternoon hours (17-18 hours). Results: analysis of the dynamics of changes in heart rate variability parameters obtained in the supine position indicates an increase in sympathetic activity in the follicular phase of the menstrual cycle. Analysis of comparisons of heart rate variability parameters in different phases of the menstrual cycle indicates that the greatest number of statistically significant (p&lt;0,05) differences is observed in the first half of the day. These changes indicate the dynamics of the decrease in the tone of the sympathetic part of the autonomic nervous system in the follicular phase when performing test tasks provided by the computer program «HRV SR+CR». Analysis of the study results indicates that the indicators of heart rate variability are also influenced by the measurement conditions. The test tasks of the computer program «HRV SR+CR» provide cognitive load and concentration of attention, especially in the second stage, where it is necessary to choose the sought-after figure. During cognitive tasks there is an increase in the activity of the parasympathetic nervous system, which leads to an increase in heart rate variability. High level of heart rate variability is associated with better cognitive functions and adaptive response to stress. Consequently, these differences in heart rate variability obtained using the «Research HRV» and «HRV SR+CR» programs may be the result of interactions between physiological changes during the menstrual cycle as well as the influence of measurement conditions. Understanding the changes in heart rate variability indices during test tasks related to the manifestation of the choice reaction provides information about the influence of cognitive load and attention concentration on the functional state of the female athlete. This will allow to plan the training process of wrestling taking into account the phases of the menstrual cycle and functional capabilities that are inherent in high-skilled female athletes. Conclusions. The parameters of heart rate variability and sensorimotor reaction time provide information about the functional state of martial artists. Understanding of metabolic and hormonal processes in different phases of the menstrual cycle of qualified wrestlers will allow to optimize their training loads and recovery measures.

Three-dimensional (3D) stimuli are always better than two-dimensional (2D) multi-tasking? A high cognitive load in 3D-MATB-II

ObjectiveThe objective of this study is to investigate the whether multi-tasking performance in (three-dimensional) 3D aid or impede cognition compare to (two-dimensional) 2D environments, as reflected by cognitive load. Specifically, we aim to examine the mechanism of multi-tasking under 3D (virtual reality [VR]) and 2D (PC monitor) conditions using the widely used Multi-Attribute Task Battery (MATB) II paradigm. MethodologyThe MATB-II sub-tasks, namely “Tracking” and “System Monitoring,” were conducted with varying task demands in both 3D conditions (Tracking Far - System Monitoring Near [TF-SN], Tracking Near - System Monitoring Far [TN-SF]) and a 2D condition with no depth perception (No Depth [ND]). Participants' cognitive load was assessed using subjective reporting (NASA-TLX) and physiological measure (root mean square of successive difference (RMSSD) of heart rate variability (HRV)). ResultsThe study found that performance was significantly better in the ND condition compared to the TF-SN and TN-SF conditions. Furthermore, higher NASA-TLX scores and lower RMSSD values were observed in the TF-SN and TN-SN conditions compared to the ND condition, providing additional support for the overall findings of the MATB-II paradigm. ConclusionThese findings suggest that processing multiple tasks in different depth planes may lead to poorer performance and increased subjective and physiological cognitive load.

Factor analysis on the performance of elite male fencing athletes.

We analyzed how stress and heart rate variability affect the performance of male fencing athletes expected to compete in various international events representing Korea. This study included 72 fencing athletes who participated in training and competition from January 2020 to December 2023. The stress was analyzed using the Sports Competition Anxiety Test (SCAT). Heart rate variability (HRV) was measured using an autonomous neurodiagnostic device (SA-6000). Heart rate variability measurement items were time domain analysis (heart rate, standard deviation of NN interval, and root mean square of the successful differences) and frequency domain analysis (total power, low frequency, and low frequency/high-frequency ratio). All athletes were classified into two categories: victory (high performance) and defeat (low performance) groups in the recent national championships. In SCAT, there was no significant difference between high and low performance. After comparing HRV, it was found that there is a significant difference in heart rates (P=0.030) and low frequency/high-frequency ratio (P=0.006) between high and low performance. heart rates and low-frequency/high-frequency ratio during the high performance were observed to be higher than during low performance. In our study, we found that SCAT does not affect performance, while HRV has been shown to have an impact on performance. These findings can be valuable for coaches and athletes in developing strategies to improve performance results, particularly for elite male fencing athletes.

Theories of Arousal Predict a Link Between Heart Rate Variability and Reactive Aggression: Meta-Analytic Results Disagree.

Polyvagal theory posits that habitually aggressive individuals might have an impaired capacity to calm after arousal, which has led to the investigation of Arousal-based biological indicators - "biomarkers" - of aggression, to identify individuals at high risk. The most popular approach in research examining (specifically reactive) aggression is the use of wearable technologies that can non-invasively measure heart rate variability (HRV), a cardiovascular phenomenon impacted by activation of the parasympathetic ("rest and digest") nervous system. But there is a problem: no one has systematically analyzed the results of these studies to determine if HRV is an effective predictor of reactive aggression. We surveyed an initial 705 articles, producing 48 effect estimates amenable to meta-analysis. Counter to predictions derived from polyvagal theory, the results reveal no correlation between HRV and reactive aggression. We discuss the implications of this novel finding for theory and practice, considering both the complexity of identifying effective biomarkers and the practical limitations driving methodological decisions in aggression research. We conclude that there is no empirical evidence supporting HRV as a valid biomarker of aggression.

Systematic review of cognitive impairment in drivers through mental workload using physiological measures of heart rate variability.

The intricate interplay between driver cognitive dysfunction, mental workload (MWL), and heart rate variability (HRV) provides a captivating avenue for investigation within the domain of transportation safety studies. This article provides a systematic review and examines cognitive hindrance stemming from mental workload and heart rate variability. It scrutinizes the mental workload experienced by drivers by leveraging data gleaned from prior studies that employed heart rate monitoring systems and eye tracking technology, thereby illuminating the correlation between cognitive impairment, mental workload, and physiological indicators such as heart rate and ocular movements. The investigation is grounded in the premise that the mental workload of drivers can be assessed through physiological cues, such as heart rate and eye movements. The study discovered that HRV and infrared (IR) measurements played a crucial role in evaluating fatigue and workload for skilled drivers. However, the study overlooked potential factors contributing to cognitive impairment in drivers and could benefit from incorporating alternative indicators of cognitive workload for deeper insights. Furthermore, investigated driving simulators demonstrated that an eco-safe driving Human-Machine Interface (HMI) significantly promoted safe driving behaviors without imposing excessive mental and visual workload on drivers. Recommendations were made for future studies to consider additional indicators of cognitive workload, such as subjective assessments or task performance metrics, for a more comprehensive understanding.

Autonomic Modulation in Parkinson’s Disease Using Whole-Body Cryostimulation: A Pilot Study

Background: Parkinson’s disease (PD) is a multifaceted neurodegenerative disorder that progressively affects both the central and peripheral nervous systems. This pilot study aimed to examine the effects of repeated whole-body cryostimulation (WBC) sessions on the sympathovagal balance in PD patients and correlate heart rate variability (HRV) indexes with peripheral biomarkers of the autonomic nervous system (ANS). Methods: Seventeen PD patients with mild to moderate motor severity underwent a 10-session WBC cycle over 5 consecutive days. Thirteen patients (6 males, 7 females; mean age 64.5 ± 9.01 years; mean disease duration 5.4 ± 2.3 years) completed the protocol. Cardiac autonomic activity was assessed through HRV measures including RR interval variability (RR mean, RR min, RR max), power density of high and low frequencies (HF, LF), RMSSD, and the LF/HF ratio. Systemic sympathetic activity was evaluated via circulating blood catecholamine levels. Results: Significant increases were observed in RR mean, RR min, RR max, RMSSD, and HF spectrum, indicating enhanced parasympathetic activity. Blood pressure remained stable, suggesting safety. Conclusions: These findings provide initial support to WBC as a potential “rehabilitation booster” in PD, enhancing sympathovagal balance. Further research is needed to explore the long-term benefits of WBC in PD management.

Assessment of Physiological Signals from Photoplethysmography Sensors Compared to an Electrocardiogram Sensor: A Validation Study in Daily Life.

Wearables with photoplethysmography (PPG) sensors are being increasingly used in clinical research as a non-invasive, inexpensive method for remote monitoring of physiological health. Ensuring the accuracy and reliability of PPG-derived measurements is critical, as inaccuracies can impact research findings and clinical decisions. This paper systematically compares heart rate (HR) and heart rate variability (HRV) measures from PPG against an electrocardiogram (ECG) monitor in free-living settings. Two devices with PPG and one device with an ECG sensor were worn by 25 healthy volunteers for 10 days. PPG-derived HR and HRV showed reasonable accuracy and reliability, particularly during sleep, with mean absolute error < 1 beat for HR and 6-15 ms for HRV. The relative error of HRV estimated from PPG varied with activity type and was higher than during the resting state by 14-51%. The accuracy of HR/HRV was impacted by the proportion of usable data, body posture, and epoch length. The multi-scale peak and trough detection algorithm demonstrated superior performance in detecting beats from PPG signals, with an F1 score of 89% during sleep. The study demonstrates the trade-offs of utilizing PPG measurements for remote monitoring in daily life and identifies optimal use conditions by recommending enhancements.

Autonomic rehabilitation: Vagal and sympathetic impacts of modified occipitomastoid suture V-spread.

Autonomic rehabilitation using osteopathic manipulative treatment (OMT) to stimulate the vagus nerve may be a good adjunct therapy by physiatrists who treat dysautonomia. Heart rate variability (HRV) may provide quantitative evidence for the benefits of OMT on autonomic nervous system function. Elevated HRV indicates optimal health and reduced mortality risk, whereas low HRV is associated with stress, pain, and chronic disease pathology. To analyze the impact of modified occipitomastoid suture v-spread OMT technique on vagal tone by measuring HRV. Within-participant design with 5-minute HRV measurement pre- and post-OMT treatment. Clinical examination suites. Thirty healthy osteopathic medical students. A modified occipitomastoid suture v-spread treating somatic dysfunction by osteopathic physicians trained in osteopathic neuromusculoskeletal medicine. HRV variables related to vagal tone including root mean square of successive differences (RMSSD), percentage of successive normal sinus RR intervals >50 ms (pNN50), high frequency (HF), Parasympathetic Nervous System Index (PNSI), and Sympathetic Nervous System Index (SNSI). Repeated measures t-test analyzed the difference in mean HRV values after OMT. There were statistically significant increases in each of the HRV measures after OMT. Participants had a mean (95% confidence interval) RMSSD of 50.5 ms (38.3-62.8) at baseline and 55.0 ms (41.2-68.7, p = .013) post-OMT. pNN50 was 24.5% (17.6-31.3, n = 30) at baseline and 28.2% (20.8-35.6, p = .003) post-OMT. HF was 1549.6 ms2 (389.8-2709.4) at baseline and 1901.8 ms2 (618.2-3185.4, p = .103) post-OMT. PNSI was -0.1 (-0.5 to 0.2) at baseline and 0.1 (-0.3 to 1.5, p < .01) post-OMT, and SNSI was 0.2 (-0.1 to 0.6) at baseline and 0.05 (-0.3 to 0.4, p < .01) post-OMT. Normalization, due to high baseline variance, results include RMSSD 1.1 ms (1.0 to 1.1, p = .012), pNN50 1.3 (1.1 to 1.4, p = .011), and HF 1.2 ms2 (1.1 to 1.4, p = .018). Modified occipitomastoid suture v-spread may provide clinical benefit through increased vagal tone and decreased sympathetic activity.

The Effect of Different Resistance Training Protocols on Cardiac Autonomic Modulation During Exercise Recovery: A Crossover, Randomized, and Controlled Pilot Study

Purpose: This study investigated the impact of two different resistance training (RT) protocols on cardiac autonomic modulation during exercise recovery in trained individuals. It was hypothesized that a hypertrophic resistance training program would induce more significant stress and negatively affect cardiac autonomic modulation compared to a power/force resistance training program. Methods: Six healthy, trained participants (aged 18–40) were randomized in a crossover and controlled pilot study. Participants performed two RT protocols: (i) three sets of 10 repetitions with 85% of 10 RM, 60 s inter-set rest (3x1060s) and (ii) eight sets of three repetitions with 85% of 3 RM, 120 s inter-set rest (8x3120s). Heart rate variability (HRV) was measured before and 30 min after each RT session. Results: Significant reductions in HRV parameters (RMSSD, HF, and SD1) were observed following the 3x1060s protocol (hypertrophic design) compared to baseline. Conversely, the 8x3120s (power/force design) protocol did not show significant changes in HRV parameters. A significant interaction effect for time and RT protocol was found for all HRV measures with more significant reductions observed after 3x1060s compared to 8x3120s. Conclusions: The hypertrophic RT session (3x1060s) significantly reduced HRV parameters, suggesting higher physiological stress and potentially negative implications for cardiac autonomic recovery than the power/force RT session (8x3120s). These findings highlight the importance of considering exercise intensity and protocol design to manage cardiac autonomic stress during resistance training.

Acute Alcohol Consumption and Arrhythmias in Young Adults: The MunichBREW II Study.

and aims: Acute excessive alcohol intake may cause the holiday heart syndrome, characterized by cardiac arrhythmias including atrial fibrillation. Since underlying data are scarce, the study aimed to prospectively investigate the temporal course of occurring cardiac arrhythmias following binge drinking in young adults. A total of 202 volunteers planning acute alcohol consumption with expected peak breath alcohol concentrations (BAC) of ≥1.2 g/kg were enrolled. The study comprised 48-hour electrocardiogram (ECG) monitoring covering baseline (hour 0), 'drinking period' (hours 1-5), 'recovery period' (hours 6-19), and two control periods corresponding to 24 hours after the 'drinking' and 'recovery periods', respectively. Acute alcohol intake was monitored by BAC measurements during the 'drinking period'. ECGs were analyzed for mean heart rate, atrial tachycardia, premature atrial complexes (PAC), premature ventricular complexes (PVC), and heart rate variability (HRV) measures. Data revealed an increase in heart rate and an excess of atrial tachycardias with increasing alcohol intake. HRV analysis indicated an autonomic modulation with sympathetic activation during alcohol consumption and the subsequent 'recovery period', followed by parasympathetic predominance thereafter. PACs occurred significantly more frequently in the 'control periods', whereas PVCs were more frequent in the 'drinking period'. Ten participants experienced notable arrhythmic episodes, including atrial fibrillation and ventricular tachycardias, primarily during the 'recovery period'. The study demonstrates the impact of binge drinking on heart rate alterations and increased atrial tachycardias during 'drinking period', and the occurrence of clinically relevant arrythmias during the 'recovery period', emphasizing the holiday heart syndrome as a health concern.