Heart Rate Variability Responses Research Articles

Heart rate variability responses to cognitive stress in fibromyalgia are characterised by inadequate autonomous system stress responses: a clinical trial

Fibromyalgia (FM) is associated with sympathetically dominant dysautonomia, but the connection between dysautonomia and FM symptoms is unclear. Dysautonomia can be analysed with heart rate variability (HRV) and it has been proposed that FM patients comprise subgroups with differing profiles of symptom severity. In our study, 51 female FM patients aged 18 to 65 years and 31 age-matched healthy female controls followed a 20-min protocol of alternating relaxation and cognitive stress (mental arithmetic). Heart rates and electrocardiograms were registered. The HRV measures of heart rate (HR), mean interval between heart beats (RRmean), root mean squared interval differences of successive beats (RMSSD), and the standard deviation of intervals between normal heart beats (SDNN) were analysed with generalized linear modelling. Features in HRV reactivity which differed between FM patients and controls were used to cluster the FM patients and cluster characteristics were analysed. FM patients had higher baseline HR (72.3 [SD 12.7] vs 64.5 [7.80], p < 0.001) and lower RRmean (0.844 [0.134] vs 0.934 [0.118], p = 0.002), compared with controls. They also reacted to repeated cognitive stress with an attenuated rise in HR (− 4.41 [95% CI − 7.88 to − 0.93], p = 0.013) and attenuated decrease of RRmean (0.06 [95 CI 0.03 to 0.09], p < 0.001), compared with controls. Clustering of FM patients by HRV reactivity resulted in three clusters characterised by (1) normal levels of HRV and HRV reactivity with low levels of depressive mood and anxiety, (2) reduced levels of HRV and impaired HRV reactivity with increased levels of depressive mood and high levels of anxiety, and (3) lowest HRV and most impaired HRV reactivity with the highest scores for depressive mood and anxiety. Our results show that FM patients have lower HRV than healthy controls and their autonomous reactions to cognitive stress are attenuated. Dysautonomia in FM associates with mood disturbance.Trial registration ClinicalTrials.gov (NCT03300635). Registered October 3 2017—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03300635.

Better forbearance, lower depression: Evidence based on heart rate variability.

The relationship between forbearance, a psychological resource, and depression has to date remained inconclusive. The present study investigated heart rate variability (HRV) reactivity to acute stressor tasks in participants with different levels of forbearance to discover how forbearance influences depressive emotions when facing adversity. The study examined the relationship between forbearance and depression, comparing HRV reactivity to stressor tasks in participants with different levels of forbearance. The levels of reported forbearance were assessed by the Forbearance Scale (FS). The Patient Health Questionnaire-9 (PHQ-9) was used to assessed depression severity. HRV reactivity was evaluated at five stages: baseline, the active stressor task, the period of recovery after the active stressor task, the passive stressor task, the period of recovery after the passive stressor task. FS scores had a significant negative correlation with PHQ-9 and a significant positive correlation with HRV; significant differences existed between the basal HRV in the higher and lower FS groups. In the passive stressor task and the period of recovery after the active stressor task, significantly different HRV responses were identified between the two groups. Forbearance was correlated with depression and HRV. The present research found differences in HRV among subjects with different levels of forbearance in the baseline as well as stressor and recovery periods, suggesting that self-regulation dysfunction may exist among persons with lower levels of forbearance. Because of the higher levels of forbearance, the negative emotions of individuals caused by adversity are mitigated.

Heart Rate Variability among Healthy Untrained Adults during Mild Intensity Stationary Cycling Exercise.

Stationary cycling is the popular, preferred, and convenient form of exercise. During exercise, autonomic modulation is seen which can be assessed by heart rate variability (HRV). The aim of the study was to evaluate the changes in HRV during mild-intensity cycling exercise. An observational cross-sectional study was done on 20 healthy male volunteers with the age (35.44 ± 4.12), height (71.12 ± 11.98), and weight (161.23 ± 11.65), BMI (27.12 ± 3.49) attending various YOGA sessions in AYUSH OPD. Volunteers underwent an exercise program at the mild intensity of 30% to 50% of maximal heart rate on a stationary cycle for 20 min. HRV was recorded by the HRV mobile unit Dynamika Machine at rest, every 5 min (4×) over 20 min and during the recovery period. Repeated measures of analysis of variance with post-hoc analysis with Bonferroni and Holm's multiple comparisons. Significant change was observed in mean heart rate and time domain parameters. Frequency domain parameters that showed significant change were total power, High Frequency- HF (ms2), Very Low Frequency -VLF (ms2), Low Frequency -LF (ms2), and Very Low Frequency %-VLF (%). The HRV parameters conclusively point towards cardiac parasympathetic withdrawal and sympathetic dominance at the initiation of exercise. With the progression of exercise, the sympathetic influence is retained. In the recovery period parasympathetic reactivation gains control over heart rate as well as HRV. The HRV response to exercise challenges may be helpful in designing exercise programs based on variations in the autonomic response.

Hemodialysis Effects on Autonomic Function: Results of Linear and Nonlinear Analysis of Heart Rate Variability at Rest and in Response to Physical and Mental Stress Tests

Introduction: Cardiac arrhythmias are the most common cause of death in hemodialysis. Autonomic dysfunction plays a central role in this arrhythmogenic background. Previous studies on hemodialysis-related changes in heart rate variability (HRV) give contradictory results. This study investigated HRV indices both at rest and in response to physical and mental stimulation maneuvers at multiple time-points around and during the hemodialysis procedure. Methods: Autonomic function was assessed by linear and nonlinear HRV indices at predialysis, during dialysis (3 equal time-periods), postdialysis, and on the nondialysis day in 36 hemodialysis patients. Continuous measurement of beat-by-beat heart rate was recorded with Finometer-PRO (The Netherlands) at rest and after orthostatic, sit-to-stand, handgrip, and mental-arithmetic test. Results: The RMSSD, SD1, and SD2 indices significantly increased during dialysis (early-HD, mid-HD, late-HD periods) compared with the predialysis levels (p < 0.05) and returned to baseline postdialysis (RMSSD: 54.39 ± 83.73 vs. 137.98 ± 109.53* vs. 119.85 ± 97.34* vs. 144.47 ± 88.74* vs. 85.82 ± 121.43msec, *p < 0.05 vs. predialysis and postdialysis). No differences were detected in the above indices between the predialysis and nondialysis day. However, postdialysis, the HRV responses to orthostatic and sit-to-stand tests were more exaggerated than in the predialysis measurements (p < 0.05). The HRV responses both at resting and physical tests in the nondialysis day were similar to the predialysis levels. HRV indices in the mental arithmetic test during hemodialysis were much higher than at the nondialysis day (RMSSD: 77.05 [180.41] versus 19.75 [105.47] msec; p = 0.031). Conclusions: Hemodialysis causes marked changes in the autonomic function. Resting HRV indices return to baseline postdialysis, but HRV responses to physical stress remain exaggerated and return to baseline on the nondialysis day. Detecting patients with significant autonomic dysfunction may help towards reduction of arrhythmia risk through individualized approaches.

At Crossroads in a Virtual City: Effect of Spatial Disorientation on Gait Variability and Psychophysiological Response among Healthy Older Adults

Introduction: Aging has been associated with a decline in cognitive and motor performance, often expressed in multitasking situations, which could include wayfinding. A major challenge to successful wayfinding is spatial disorientation, occurring mostly at crossings. Although gait changes have been observed in various dual-task conditions, little is known about the effect of disorientation on gait and psychophysiological response among older adults during wayfinding. The study aimed at identifying the effect of spatial disorientation on gait variability and psychophysiological response among healthy older adults during wayfinding in a controlled environment. Method: We analyzed data of 28 participants (age 70.8 ± 4.6, 18 female), 14 experimental and 14 controls. Participants performed a wayfinding task consisting of 14 major decision points (7 intersections) within a virtual environment (VE) projected on a 180° screen while walking on a self-paced treadmill equipped with a marker-based optical motion-capture system. The VE was held constant for the controls and manipulated for the experimental participants. Disorientation was identified based on a customized annotation scheme. Variability in gait, including the coefficient of variation (CV), was measured as the primary endpoint. Psychophysiological response measures, including heart rate variability (RMSSD) and skin conductance response (SCR), were continuously monitored as secondary endpoints and estimates of cognitive effort. Linear Mixed Effects models were applied to hypothesis-driven outcome measures extracted from decision points. Results: Walking speed and step length decreased when disoriented (p < 0.05), while stride time, stance time, walking speed CV, stance time CV, SCR amplitude, and SCR count increased when disoriented (p < 0.05). A higher RMSSD was associated with being disoriented at crossings (p < 0.05). SCR count was greater in the older experimental group (p < 0.001), including when disoriented (p < 0.001). Discussion/Conclusion: The results provide evidence for the impact of spatial disorientation on changes in gait pattern and psychophysiological response among older adults during wayfinding. Location also had implications for the effect of disorientation on gait and cognitive effort. This gives further insight into the substrates of real-world navigation challenges among older adults, with an emphasis on viable features for designing situation-adaptive interventional devices aiding independent mobility.

Acute Effects of a Single-Session of Full-Body Foam Rolling on Heart Rate Variability.

Self-myofascial release has been demonstrated to increase relaxation and improve blood flow, yet it is unknown if it can elicit an acute effect on heart rate variability (HRV). This study aimed to determine if a single-bout of foam rolling could increase parasympathetic activity as measured by HRV. Twenty (20) participants volunteered and their baseline HRV was assessed using a finger sensor while lying supine, and then a second measure was recorded with them sitting upright with feet on the ground. This study utilized a practical HRV collection method designed for use in the field settings, and the data is recorded in arbitrary units (A.U.). Participants then oscillated on a closed-cell cylindrical foam roller using their body weight on the triceps surae, hamstrings, quadriceps, lumbar spine, and pectoral muscles each for 60 sec. Participants first massaged the right limb and then repeated on the matching muscle group on the left before continuing to the next region. Follow-up HRV measurements were recorded using the same procedures. Paired samples t tests assessing pre- and post-foam-rolling HRV measures in supine and seated positions revealed no difference between supine measures (p = .05, d = 0.21), nor the seated measures (p = .27, d = 0.17) among all participants. When sexes were analyzed separately, males showed a significant decrease in HRV in supine positions (p = .03, d = 0.33), but females did not (p = .55, d = 0.09). The single bout of foam rolling on large muscle groups did not increase parasympathetic activity as hypothesized. Males and females responded differently in supine positions, but no difference was present in seated positions across sexes. The task of self-massage may have prevented the anticipated response from the massage. Further research should investigate if passive massage is more effective on HRV response.

Effect of Baseline Status on Cardiovascular Responses Post-isometric Handgrip Exercise

Abstract Background Isometric handgrip (IHG) exercise causes changes in heart rate variability (HRV) and hemodynamic responses with individual differences. We test the hypothesis that baseline measurements affect post-exercise outcomes. Methods In this cross-sectional study, 45 males aged 17 to 22 were enrolled from SMS Medical College, Jaipur, India. Hemodynamic and HRV data were collected at baseline, during, and after 5 minutes of IHG exercise. Nonparametric tests compared the absolute and relative responses before, during, and after the exercise. The relationship of baseline measurements with outcomes was evaluated using Pearson's correlation. Results The study showed a significant increase in the absolute values of hemodynamic parameters and LF/HF ratio during and after 5 minutes of IHG exercise compared to the baseline. However, a significant decrease and increase occurred in all the relative hemodynamic parameters and most HRV parameters, respectively, after rather than during the 5 minutes of IHG exercise. Hemodynamic parameters significantly correlated with baseline during and after 5 minutes of IHG exercise. Similarly, baseline affects all the HRV parameters during IHG exercise, but not after 5 minutes of IHG exercise. Conclusion The present study concludes that initial baseline status should be considered while evaluating the post-IHG exercise responses.

The short term adaptation of the autonomic nervous systems (ANS) by type of urban environment and ethnicity

BackgroundPrevious studies examined the effects of urban environments on the Autonomic Nervous System (ANS). These studies measured the effects of environments on Heart Rate Variability (HRV) averaging different time intervals to one value. Yet, the dynamics of change, reflecting the functions and their derivatives that describe the adaptation to the new environments remain unknown. In addition, ethnic differences in the ANS adaptation were not investigated.Method: Forty-eight Arab and 24 Jewish women ages 20–35 years, all healthy, non-smokers were recruited by a snowball sample. Both groups were of a similar socioeconomic status and BMI distributions. Using a portable monitor, the HRV response was continuously analyzed for 35 min of sedentary sitting in each of the three environments: a park, a city center and a residential area. LF/HF polynomial function was adapted to describe the dynamic change in each environment for each ethnic group. ResultsGreen area exposure was associated with 90% immediate change while in built-up areas, the change in HRV is about 40% adaptive (changing gradually). The adaptive process of HRV may stabilize after 15 min in the city center yet not even after 35 min in the residential environment. The total change (immediate + adaptive) reached 24% in city centers and 10% in residential areas. Changes in HRV rates in the park and the city center environments were higher among Arab women as compared to Jewish women but similar between the two groups in the residential area. The distributions of LF/HF in each time cohort were normal, meaning that shifting the focus to analyze functions of change in HRV, opens the possibility to employ analytic methods that assume the normal distribution. ConclusionsChanging the focus from average levels of HRV to functions of change and their derivatives brings new insight into the understanding of the ANS response to environmental challenges. ANS short term adaptation to different environments is gradual and spans differently both in magnitude of response and latencies between different environments. Importantly, in green areas, the response is immediate unlike the adaptation to urban environments that is significantly more gradual. The ethnic differences in ANS adaptation is also noteworthy. In addition, adaptation proceeesses are normaly distributed in each time cohort suggesting a possible novel ANS index.

Relation of Young Children's Parasympathetic Reactivity During a Learning Task to Their Self‐Regulation and Early Academic Skills

AbstractThere is growing interest among educational researchers in using heart rate variability (HRV) as an index of children's capacity to regulate their physiological arousal. Links between HRV and young children's self‐regulation have, however, been inconsistent, and there is limited research on children's HRV in learning‐related contexts. HRV was collected from 86 children aged 3.41 to 5.83 years before, during, and after they engaged in a learning interaction with an examiner. Higher HRV during a pre‐learning episode and a larger drop in HRV during the learning interaction were associated with stronger behavioral performance on self‐regulation and early academic skill assessments. Children's capacity to modulate their HRV in response to learning opportunities may be linked to their broader self‐regulation and early academic skill development. Effects varied by episode and gender, underscoring a need for further research to rigorously evaluate the utility and generalizability of HRV in authentic educational settings.

Overnight heart rate variability responses to military combat engineer training

The study aimed to determine if overnight heart rate variability (HRV) is reflective of workload and stress during military training. Measures of cognitive load, perceived exertion, physical activity, nocturnal HRV, cognitive performance and sleep were recorded for a 15-day assessment period in 32 combat engineers. The assessment period consisted of 4 phases, PRE, FIELD, BASE and RECOVERY that exposed trainees to periods of sleep deprivation and restriction. The FIELD phase was characterised by an increase in mood disturbance, perceived exertion, physical activity, HRV and a reduction in sleep quantity (p < 0.05). Measures of HRV returned to PRE-values quicker than subjective wellbeing responses. The combination of sleep duration (β = −0.002, F = 13.42, p < 0.001) and physical activity (metabolic equivalents, β = −0.483, F = 5.95, p = 0.017), the main stressors of the exercise, provided a significant effect in the best predictive model of HRV. The different recovery rates of HRV and subjective wellbeing suggest a different physiological and psychological response.

Meditative-based diaphragmatic breathing vs. vagus nerve stimulation in the treatment of fibromyalgia—A randomized controlled trial: Body vs. machine

Vagus nerve innervation via electrical stimulation and meditative-based diaphragmatic breathing may be promising treatment avenues for fibromyalgia. Explore and compare the treatment effectiveness of active and sham transcutaneous vagus nerve stimulation (tVNS) and meditative-based diaphragmatic breathing (MDB) for fibromyalgia. Participants enrolled from March 2019-October 2020 and randomly assigned to active tVNS (n = 28), sham tVNS (n = 29), active MDB (n = 29), or sham MDB (n = 30). Treatments were self-delivered at home for 15 min/morning and 15 min/evening for 14 days. Follow-up was at 2 weeks. Outpatient pain clinic in Oslo, Norway. 116 adults aged 18-65 years with severe fibromyalgia were consecutively enrolled and randomized. 86 participants (74%) had an 80% treatment adherence and 107 (92%) completed the study at 2 weeks; 1 participant dropped out due to adverse effects from active tVNS. Active tVNS is placed on the cymba conchae of the left ear; sham tVNS is placed on the left earlobe. Active MDB trains users in nondirective meditation with deep breathing; sham MDB trains users in open-awareness meditation with paced breathing. Primary outcome was change from baseline in ultra short-term photoplethysmography-measured cardiac-vagal heart rate variability at 2 weeks. Prior to trial launch, we hypothesized that (1) those randomized to active MDB or active tVNS would display greater increases in heart rate variability compared to those randomized to sham MDB or sham tVNS after 2-weeks; (2) a change in heart rate variability would be correlated with a change in self-reported average pain intensity; and (3) active treatments would outperform sham treatments on all pain-related secondary outcome measures. No significant across-group changes in heart rate variability were found. Furthermore, no significant correlations were found between changes in heart rate variability and average pain intensity during treatment. Significant across group differences were found for overall FM severity yet were not found for average pain intensity. These findings suggest that changes in cardiac-vagal heart rate variability when recorded with ultra short-term photoplethysmography in those with fibromyalgia may not be associated with treatment-specific changes in pain intensity. Further research should be conducted to evaluate potential changes in long-term cardiac-vagal heart rate variability in response to noninvasive vagus nerve innervation in those with fibromyalgia. https://clinicaltrials.gov/ct2/show/NCT03180554, Identifier: NCT03180554.

Heart rate variability and blood pressure during and after three CrossFit® sessions

CrossFit® is a training program characterized by high intensity stimulus with constantly varied and multifunctional movements that induces a significant range of physiological, hemodynamic and biochemical responses. Heart rate variability (HRV) can be used to measure how individuals react to physiological stress and fatigue. Thus, the aim of this study was to verify HRV and blood pressure acute responses during and after three sessions of Crossfit®. Nine subjects with more than one year of experience performed three different sessions of CrossFit® to verify the response of systolic blood pressure (SBP), diastolic blood pressure (DBP) and HRV. Significant reductions in HRV were observed through parasympathetic indexes (High Frequency(HF), p&lt;0.001) and an increase in the activity of sympathetic indexes (Low Frequency (LF), p &lt; 0.01; LF/HF, p&lt;0.001) after all Crossfit® workouts. SBP decreased ​​(p&lt;0.05) and there were no significant differences between workouts of the day in both HRV and SBP. Different CrossFit® sessions induced similar activity of the autonomic nervous system with reduced HRV and post-exercise hypotension. Keywords. high intensity interval training; Fran; Megan; Diane; autonomic response; post-exercise hypotensive effect.

Emotions and ensuing motor performance are altered by regulating breathing frequency: Implications for emotion regulation and sport performance.

Breathing interventions have been shown to improve sport performance. Although evidence exists to support the role of perceived arousal as a critical underlying mechanism of breathing interventions, methodological differences in the literature preclude clear understanding of potential contributing factors to the effectiveness of such interventions. Under neutral contexts, we have demonstrated attention, dyspnea, and hindrance may need to be considered as mediators of how breathing frequency affects motor performance. We sought to extend our previous findings to determine how breathing frequency affects motor performance under varying emotional conditions. Participants (N = 35, Mage = 21.68, SD = 2.96; 20 females) performed slow, normal, and fast metronome-paced breathing while viewing pleasant and unpleasant stimuli prior to executing a pinch grip task. Performance was assessed via reaction time (RT), variability (V) and error (AE). Assessment of indices of perceived arousal included measuring heart rate variability (HRV) and visual analog scale responses. Visual analog scales were also used to assess attention, dyspnea, and hindrance. Repeated measures ANOVAs showed slow breathing increased RT and HRV compared to normal and fast breathing under emotional conditions (all p’s < 0.05). Hierarchical multiple regression models revealed that decreased breathing frequency predicted increases in RT (β = −0.25, p < 0.05) under pleasant conditions, while predicting increases in HRV for unpleasant conditions (β = −0.45, p < 0.001). Increases in dyspnea (β = 0.29, p < 0.05) and hindrance (β = 0.35, p < 0.01) predicted increases in RT under pleasant conditions, while only increases in hindrance predicted increases in RT under unpleasant conditions (β = 0.41, p < 0.01). Decreases in breathing frequency predicted increases in HRV under unpleasant conditions (β = −0.45, p < 0.001). Overall, our findings suggest under varying emotional contexts breathing frequency differentially affects movement, potentially mediated by factors other than perceived arousal. In addition, these results inform the use of breath regulation as an antecedent emotion regulation strategy.

Psychophysiological effect according to restoration factors of audio-visual environment

This study investigated the effects of psychophysiological restoration due to environmental factors while experiencing the city, waterfront, and green space using various psychological scales and physiological measurement tools. The environment was experienced using virtual reality technology, and the subjects' responses were collected through surveys and EEG (electroencephalography) and HRV (heart rate variability) measurement. HRV responses were carried out by parameters such as total power (TP), SDNN and TSI. In case of EEG, PSD (power spectrum density) analysis indicated a relatively high restoration effect in the natural environment and increase of alpha-beta ratio. Based on functional connectivity, graph theory analysis showed that the limbic system network of non-restoration group was hyperactive. When comparing HRV responses (increase of TP, SDNN and reduction of TSI), from the resilience group, it was found to have higher global network efficiency. In fact, in urban space, there were fewer psychological restoration responses in the group with high noise sensitivity.

Fetal heart rate responses to maternal sleep-disordered breathing

Maternal sleep-disordered breathing is associated with adverse pregnancy outcomes and is considered to be deleterious to the developing fetus. Maternal obesity potentiates sleep-disordered breathing, which, in turn, may contribute to the effect of maternal obesity on adverse fetal outcomes. However, only a few empirical studies have evaluated the contemporaneous effects of maternal sleep-disordered breathing events on fetal well-being. These events include apnea and hypopnea with accompanying desaturations in oxyhemoglobin. This study aimed to reconcile contradictory findings on the associations between maternal apnea or hypopnea events and clinical indicators of fetal compromise. It also sought to broaden the knowledge base by examining the fetal heart rate and heart rate variability before, during, and after episodes of maternal apnea or hypopnea. To accomplish this, we employed overnight polysomnography, the gold standard for ascertaining maternal sleep-disordered breathing, and synchronized it with continuous fetal electrocardiography. A total of 84 pregnant women with obesity (body mass index >30 kg/m2) participated in laboratory-based polysomnography with digitized fetal electrocardiography recordings during or near 36 weeks of gestation. Sleep was recorded, on average, for 7 hours. Decelerations in fetal heart rate were identified. Fetal heart rate and heart rate variability were quantified before, during, and after each apnea or hypopnea event. Event-level intensity (desaturation magnitude, duration, and nadir O2 saturation level) and person-level characteristics based on the full overnight recording (apnea-hypopnea index, mean O2 saturation, and O2 saturation variability) were analyzed as potential moderators using linear mixed effects models. A total of 2936 sleep-disordered breathing events were identified, distributed among all but 2 participants. On average, participants exhibited 8.7 episodes of apnea or hypopnea per hour (mean desaturation duration, 19.1 seconds; mean O2 saturation nadir, 86.6% per episode); nearly half (n=39) of the participants met the criteria for obstructive sleep apnea. Only 45 of 2936 apnea or hypopnea events were followed by decelerations (1.5%). Conversely, most (n=333, 88%) of the 378 observed decelerations, including the prolonged ones, did not follow an apnea or a hypopnea event. Maternal sleep-disordered breathing burden, body mass index, and fetal sex were unrelated to the number of decelerations. Fetal heart rate variability increased during events of maternal apnea or hypopnea but returned to initial levels soon thereafter. There was a dose-response association between the size of the increase in fetal heart rate variability and the maternal apnea-hypopnea index, event duration, and desaturation depth. Longer desaturations were associated with a decreased likelihood of the variability returning to baseline levels after the event. The mean fetal heart rate did not change during episodes of maternal apnea or hypopnea. Episodes of maternal sleep apnea and hypopnea did not evoke decelerations in the fetal heart rate despite the predisposing risk factors that accompany maternal obesity. The significance of the modest transitory increase in fetal heart rate variability in response to apnea and hypopnea episodes is not clear but may reflect compensatory, delimited autonomic responses to momentarily adverse conditions. This study found no evidence that episodes of maternal sleep-disordered breathing pose an immediate threat, as reflected in fetal heart rate responses, to the near-term fetus.

The Effects of Alpha-Glycerylphosphorylcholine on Heart Rate Variability and Hemodynamic Variables Following Sprint Interval Exercise in Overweight and Obese Women.

The current study examined the effects of Alpha-Glycerylphosphorylcholine (A-GPC) on heart rate variability (HRV) and hemodynamic responses following a sprint interval exercise (SIE) in women who were overweight or obese. Participants (n = 12, 31.0 ± 4.6 years; 29.4 ± 2.1 kg/m2) consumed 1000 mg of A-GPC or a placebo after eating breakfast in a randomized, double-blind cross-over design. After 60 min, participants performed two bouts of the SIE (30 s Wingate) interspersed with 4 min of active recovery (40 rpm). Hemodynamic variables and HRV domains were measured before and 60 min after the A-GPC consumption, immediately after SIE, and every 15 min up to 120 min during recovery. A-GPC consumption increased resting levels of both the time domain (Standard Deviation of RR wave intervals [SDNN] and percentage of interval differences of adjacent RR intervals greater than 50 ms [pNN50%]) and frequency domain (high frequency [HF] and low frequency [LF]) variables of HRV (p < 0.05). Moreover, HRV variables (except for LF/HF) decreased (p < 0.05) immediately after SIE in the A-GPC and placebo sessions. Systolic and diastolic blood pressure increased (p < 0.05) immediately after SIE in both trials. Both HRV and hemodynamic variables recovered (p < 0.05) faster in the A-GPC compared to the placebo session. We concluded that A-GPC consumption recovers HRV and blood pressure faster following strenuous exercise in overweight and obese women, and that it might favorably modify cardiac autonomic function.

Autonomic function predicts cognitive decline in mild cognitive impairment: Evidence from power spectral analysis of heart rate variability in a longitudinal study.

BackgroundDespite the emerging clinical relevance of heart rate variability (HRV) as a potential biomarker of cognitive decline and as a candidate target for intervention, there is a dearth of research on the prospective relationship between HRV and cognitive change. In particular, no study has addressed this issue in subjects with a diagnosis of cognitive status including cognitive impairment.ObjectiveTo investigate HRV as a predictor of cognitive decline in subjects with normal cognition (NC) or Mild Cognitive Impairment (MCI). Specifically, we tested the literature-based hypothesis that the HRV response to different physical challenges would predict decline in different cognitive domains.MethodsThis longitudinal study represents the approximately 3-year follow-up of a previous cross-sectional study enrolling 80 older outpatients (aged ≥ 65). At baseline, power spectral analysis of HRV was performed on five-minute electrocardiographic recordings at rest and during a sympathetic (active standing) and a parasympathetic (paced breathing) challenge. We focused on normalized HRV measures [normalized low frequency power (LFn) and the low frequency to high frequency power ratio (LF/HF)] and on their dynamic response from rest to challenge (Δ HRV). Extensive neuropsychological testing was used to diagnose cognitive status at baseline and to evaluate cognitive change over the follow-up via annualized changes in cognitive Z-scores. The association between Δ HRV and cognitive change was explored by means of linear regression, unadjusted and adjusted for potential confounders.ResultsIn subjects diagnosed with MCI at baseline a greater response to a sympathetic challenge predicted a greater decline in episodic memory [adjusted model: Δ LFn, standardized regression coefficient (β) = −0.528, p = 0.019; Δ LF/HF, β = −0.643, p = 0.001] whereas a greater response to a parasympathetic challenge predicted a lesser decline in executive functioning (adjusted model: Δ LFn, β = −0.716, p < 0.001; Δ LF/HF, β = −0.935, p < 0.001).ConclusionOur findings provide novel insight into the link between HRV and cognition in MCI. They contribute to a better understanding of the heart-brain connection, but will require replication in larger cohorts.

Multi-trajectory analysis uncovers latent associations between psychological and physiological acute stress response patterns

Encounter with an acute stressor elicits multiple physiological and psychological response trajectories that spread at different times-scales and directions. Associating a single physiological response trajectory with a specific psychological response has remained a challenge, due to putative interactions between the different stress response pathways. Hence, multidimensional analysis of stress response trajectories may be better suited to account for response variability. To test this, 96 healthy female participants underwent a robust acute laboratory stress induction procedure while their psychological [positive and negative affect (PANAS)] and physiological [heart rate (HR), heart rate variability (HRV), saliva cortisol (CORT)] responses were recorded before, during and after stress. Combining these data using unsupervised group-based multi-trajectory modelling uncovered three latent classes that best accounted for variability across psychological and physiological stress response trajectories. These classes were labelled based on their psychological response patterns as: A prototypical response group that depict a moderate increase in negative and decrease in positive affect during stress, with both patterns recovering after stress offset (n = 55); A heightened response group that depict excessive affective responses during stress that recover after stress offset (n = 24); and a lack of recovery group that depict a moderate increase in negative and decrease in positive affect during stress, with both patterns not recovering after stress offset (n = 17). With respect to physiological acute stress trajectories, all three groups exhibited comparable increases in HR and CORT during stress that recovered after stress offset, yet only the prototypical group expressed the expected stress-induced reduction in HRV, while the other two groups exhibited blunted HRV response. Critically, focusing on a single physiological stress response trajectory, including HRV, did not account for psychological response variability and vice versa. Taken together, a multi-trajectory approach may better account for the multidimensionality of acute stress response and uncover latent associations between psychological and physiological response patterns. Compared to the other two groups, the prototypical group also exhibited significantly lower overall stress scores based on the DASS-21 scale. This, alongside the uncovered response patterns, suggest that latent psycho-physiological associations may shed light on stress response adaptivity or lack thereof.

Pilot examination of stress, heart rate variability, and alcohol craving and use among female veterans.

Rates of alcohol use disorder (AUD) are increasing among civilian and veteran populations of women in the United States, and stress pathophysiology (i.e., abnormal acute and long-term change in physiological responses to stress) is central to the maintenance of alcohol misuse within this population. Heart rate variability (HRV) is one measure of stress regulation that may help to explain the association of stress with alcohol misuse among women. In the current analysis of pilot data, 20 women veterans attended an in-person laboratory session and completed 35 daily assessments of their alcohol use and craving. During the lab session, the effects of a stress induction procedure on self-reported alcohol craving and HRV were assessed. HRV was continuously measured and indexed in the time domain, using the root mean square of successive differences between normal heartbeats (RMSSD). Alcohol craving and use during the longitudinal 35-day study period were measured via self-report questionnaires sent to participants' phones. Results indicated that resting HRV in the lab was positively associated with odds of daily craving. Moreover, HRV during the stressor, as measured in lab, was positively associated with (1) overall alcohol craving in the lab (i.e., with resting and post-stress craving), and (2) number of daily drinks during the 35-day study period. This pilot study suggests the potential role of HRV in response to stressors in predicting alcohol craving and use among female veterans. It provides pilot data for research on stress-reactive HRV as a biomarker for alcohol misuse among women, and discusses directions for future research.

Sex Differences In Heart Rate Variability During Arm And Leg Cycling

Heart rate variability (HRV) is a biomarker that can provide insight into cardiac autonomic function. HRV can be affected by sex, different modes of exercise, and different exercise intensities. However, HRV responses to intensities based on mode-specific cardiopulmonary parameters in arm and leg cycling have yet to be examined in males and females. PURPOSE: The purpose of this study was to investigate HRV obtained during an isocaloric arm and leg cycling exercise performed at heavy and moderate intensities. METHODS: A total of 14 females (age = 24.2 ± 6.0 years, BMI = 24.4 ± 4.7 kg/m2) and 10 males (age = 22.8 ± 1.9 years, BMI = 26.8 ± 6.2 kg/m2) were included in the final analysis. The participants completed four different isocaloric exercise trials until they reached 100 kcal: moderate intensity leg cycling, heavy intensity leg cycling, moderate intensity arm cycling, and heavy intensity arm cycling. The intensity was determined relative to the ventilatory threshold and maximal power output attained during a graded exercise test for arm and leg cycling. A heart rate monitor recorded the R-R intervals at 1000 Hz and the root mean square of the standard deviation of the R-R intervals (RMSSD) were analyzed using specialized software. A three-way (mode x intensity x sex) repeated measures ANOVA was used to compare the average (log transformed) RMSSD achieved during each trial. Alpha was set at 0.05. RESULTS: A significant interaction was found between mode and sex (p = 0.026). Post-hoc analysis revealed higher RMSSD during arm cycling as compared to leg cycling for females (p < .01) but no difference in males (p > 0.05). A significant main effect for intensity (p < 0.01) was also shown with lower RMSSD for heavy (1.37 ± 0.07 ms) compared moderate (2.02 ± 0.07 ms) exercise intensities. CONCLUSION: Sex-based differences in RMSSD could signify unique autonomic nervous system responses during exercises of different modes. In our female participants, we found a higher level of cardiac parasympathetic nervous activation during arm cycling compared to leg cycling. This difference was not found in our male participants. These differences could be related to a different respiratory control during exercise.