High-frequency Heart Rate Variability Research Articles

0170 Slow Oscillation Power and Heart Rate Variability During Sleep Predicts Next-day Subjective Sleepiness in Healthy, Young Adults

Abstract Introduction High amplitude, slow oscillations in the electroencephalogram (EEG) often characterize the central nervous system’s homeostatic drive for sleep. Slow oscillations dominate the first part of the night and often dissipate as sleep need is satiated. These physiological changes are also reflected in next day subjective measures of sleepiness. Fluctuations in the autonomic nervous system, particularly parasympathetic activity, also coincide with slow wave sleep and are understood to represent bodily homeostasis. However, it is unclear if autonomic indicators effectively predict next-day sleepiness. Here, we investigated whether slow oscillatory (SO) power and cardiac autonomic activity during a night of sleep can predict next day subjective sleepiness. Methods 88 young (aged 18-35), healthy participants spent the night in a University sleep lab. Before and after sleep, participants completed the Karolinska Sleepiness Scale (KSS) to measure subjective sleepiness. Each participant slept with polysomnography, including electroencephalography and electrocardiography. From these measures, we assessed slow oscillation power (0.5-1Hz) and high frequency heart rate variability (HRV; 0.15-0.45 Hz) --an indicator of parasympathetic, vagally-mediated cardiac tone-- during the first quartile of slow wave sleep. Paired T-tests compared the differences in KSS scores pre- and post-sleep. Pearson’s correlations assessed bivariate associations between slow oscillatory power, high frequency HRV, and KSS scores. Mixed linear models assessed the ability of SO power and high frequency HRV to predict next day subjective sleepiness. Results No significant differences were found in KSS ratings pre- (M±SD = 4.23±1.92) and post-sleep (4.38±1.80). No bivariate correlations were present between pre-sleep KSS, SO, or high frequency HRV. A significant correlation between KSS-post sleep and SO power emerged (r=0.286, p=0.001). In Model 1, we found that SO power was a predictor of subjective sleepiness (p<0.001; AIC: 777.469). In Model 2, we included high frequency HRV and reduced the AIC to 515.588. Both slow oscillatory power (p<0.001) and high frequency HRV (p<0.001) were significant predictors of KSS after sleep in Model 2. Conclusion We found evidence that both central and autonomic indicators of sleep predict psychological measures of sleepiness. Using autonomic indicators to characterize physiological sleepiness, compared to in-lab polysomnography, may be a more generalizable and cost-effective approach. Support (If Any)

0149 Reliability of Heart Rate Variability during Stable and Disrupted Polysomnographic Sleep

Abstract Introduction Heart rate variability (HRV) is a common metric to estimate autonomic activity during sleep. Frequency-domain HRV is quantified as low (LF) and high (HF) frequency, whereas HRV time-domain indices include root mean square of successive R-R interval differences (RMSSD), and percentage of successive R-R intervals differing by more than 50ms (pNN50). Despite high HRV use during sleep, it is unknown whether sleep disturbance changes overall reliability of frequency- and time-domain HRV. The purpose of this present study was to determine whether HRV was reliable across arousal-free and arousal-containing periods of sleep. Methods Twenty-seven participants (11 male, 16 female, 26±1 years, 27±1 kg/m2) were given an 8-hour sleep opportunity, equipped with continuous two-lead electrocardiography (ECG) and overnight polysomnography (PSG). The ECG recordings were analyzed via fast-Fourier transformation for frequency-domain HRV in a custom software as LF (0.04-0.15 Hz) and HF (0.15-0.4 Hz) HRV. Time-domain HRV was quantified as RMSSD and pNN50. Two separate stable sleep periods (range, 5-10min) absent of arousals were recorded, along with two separate disrupted periods of sleep with at least one arousal were selected in stage II sleep (N2), slow wave sleep (SWS), and rapid eye movement (REM) sleep. LF and HF HRV was log10 transformed due to non-normal distribution. Statistical analysis included intraclass correlations (ICC) of HRV across the four stable and disrupted periods of sleep, with separate ICC analyses across sleep stages (α = 0.05). Results Time-domain measures (RRI, RMSSD, pNN50) were reliable across arousal-free and arousal-containing sleep cycles, for all three stages (ICC>0.9, p<0.05). HF HRV exhibited similar reliability patterns across N2 sleep (ICC=0.960, p<0.001), SWS (ICC=0.955, p<0.001), and REM sleep (ICC=0.924, p<0.001). LF HRV was reliable in two stages of stable and disrupted sleep in N2 (ICC=0.903, p<0.001), REM (ICC=0.907, p<0.001) sleep, and trending in SWS (ICC=0.616, p=0.089) sleep. Conclusion Time- and frequency-domain HRV were reliable between stable sleep with and without cortical arousals, with the exception of LF HRV during SWS. Taken together, HRV may provide a reliable, indirect index of autonomic activity across stable and disrupted sleep. Support (If Any) Support: Support is provided by the National Institutes of Health (AA-024892; U54GM115371; P20GM103474).

0111 Effects of Sleep on Working Memory

Abstract Introduction Improvements in working memory (WM) are associated with increased vagal autonomic activity during sleep. Sex hormones, which fluctuate across a menstrual cycle, influence sleep, autonomic activity, and cognitive performance. Given this complex interaction, we examined whether the relation between WM improvement and autonomic activity across a night of sleep was modulated by menstrual phase. Methods Twenty-five healthy female participants with natural, regular menstrual cycles (age = 28.14 ± 4.41 years) were enrolled. We employed a within-subject design to investigate the role of menstrual phase on autonomic activity and sleep-dependent working memory improvement. All participants completed two in-lab visits, with one visit during their low hormones phase (LH: 0 to +2 days from the start of menses) and one visit during their high hormone phase (HH: +1 to +4 days from the start of ovulation). We measured WM with the Operation-Span Task at 9PM and 8AM. Participants’ overnight sleep was monitored with EEG and ECG. We measured parasympathetic activity using the high-frequency heart rate variability (hfHRV) and the root-mean-square of successive differences between normal heartbeats (RMSSD). We used linear-mixed effect models and Pearson’s r. Results No differences in WM were found between menstrual phases (all ps > .223). Interestingly, however, HRV during NREM positively correlated with WM improvement in LH (hfHRV: r = .329, p = .093; RMSSD: r = .327, p = .096), but not during HH (hfHRV: r = -.197, p = .355; RMSSD: r = -.179, p = .402). The differences between correlations were significant (hfHRV: p = .038; RMSSD: p = .045). Conclusion Prior meta-analysis revealed greater vagal autonomic activity during LH (menses), compared with other phases. Though we didn’t replicate this finding, we did show a significantly stronger relation between vagal autonomic activity and overnight WM improvement during this low hormone phase. Our results suggest that menstrual phase shifts the reliance of sleep-dependent WM improvement to vagal autonomic mechanisms. Support (If Any) UCI MIND/WAM 02-2020

Evaluation of Heart Rate Variability and Application of Heart Rate Variability Biofeedback: Toward Further Research on Slow-Paced Abdominal Breathing in Zen Meditation.

This review summarizes my own involvement in heart rate variability (HRV) and HRV biofeedback studies, as a tribute to the late Dr. Evgeny Vaschillo. I first review psychophysiological studies on behavioral stress and relaxation performed in my laboratory using an assessment of cardiac parasympathetic activity. Although magnitude of high-frequency (HF) component of HRV corresponding respiratory sinus arrhythmia (RSA) is widely used as an index of cardiac parasympathetic function, a respiratory confound during stress or relaxation may have interfered with the proper assessment of the HF HRV. An enhanced method under frequency-controlled respiration at 0.25Hz provided a reliable assessment of cardiac parasympathetic activity. I then review findings from HRV biofeedback research in my laboratory. Based on the hypothesis that RSA measured as an HF component of HRV represents cardiorespiratory resting function, it was demonstrated that HRV biofeedback before sleep enhanced the magnitude of HF HRV during sleep, a cardiorespiratory resting function. Moreover, by focusing on the spectral peak of the low-frequency (LF) component of HRV, paced breathing at the LF-peak frequency was shown to increase baroreflex sensitivity. Finally, I describe the potential of slow-paced abdominal breathing (i.e., Tanden breathing) performed in Zen meditation. The concept of Tanden breathing as described in a regimen from early modern Japan is introduced, and recent research findings on slow-paced abdominal breathing are summarized. Future research directions of slow-paced abdominal breathing are also discussed.

An event-based analysis of maternal physiological reactivity following aversive child behaviors.

Research investigating the association between parents' physiological reactivity and their ability to self-regulate in parenting contexts typically examines the average physiological response across the duration of a dyadic task, conflating reactivity across a multitude of parent and child behaviors. The present study utilized a moving-window analytical technique to generate a continuous, second × second time series of mothers' high-frequency heart rate variability (HF-HRV) to conduct an event-based analysis of maternal reactivity in the 10s following an aversive child event. Analyses examined whether maternal reactivity related to parenting behaviors similarly among maltreating (n=48) and non-maltreating (n=29) mother-preschooler dyads. Results indicate that maternal behavior was not associated with average HF-HRV reactivity, but mothers who demonstrated an increase in HF-HRV immediately following a negative child event were more likely to engage in behaviors to return the dyad to a positive state. Findings were specific to incidents of negative child behavior, and results were not moderated by maltreatment status. These results highlight the value of using an event-based design to isolate reactivity in response to targeted events to understand how physiological reactivity supports parenting.

Reliability of heart rate variability during stable and disrupted polysomnographic sleep.

Heart rate variability (HRV) is commonly used within sleep and cardiovascular research, yet HRV reliability across various sleep stages remains equivocal. The present study examined the reliability of frequency- and time-domain HRV within stage-2 (N2), slow-wave (SWS), and rapid-eye-movement (REM) sleep during both stable and disrupted sleep. We hypothesized that high-frequency (HF) HRV would be reliable in all three sleep stages, low-frequency (LF) HRV would be reliable during N2 and SWS, and that disrupted sleep via spontaneous cortical arousals would decrease HRV reliability. Twenty-seven participants (11 men, 16 women, 26 ± 1 yr) were equipped with laboratory polysomnography for 1 night. Both frequency- and time-domain HRV were analyzed in two 5- to 10-min blocks during multiple stable and disrupted sleep cycles across N2, SWS, and REM sleep. HF HRV was highly correlated across stable N2 (r = 0.839, P < 0.001), SWS (r = 0.765, P < 0.001), and REM (r = 0.881, P < 0.001). LF HRV was moderate-to-highly correlated during stable cycles of N2 sleep (r = 0.694, P < 0.001), SWS, (r = 0.765, P < 0.001), and REM (r = 0.699, P < 0.001) sleep. When stable sleep was compared with disrupted sleep, both time- and frequency-domain HRV were reliable (α > 0.90, P < 0.05) in N2, SWS, and REM, except for LF HRV during SWS (α = 0.62, P = 0.089). In conclusion, time- and frequency-domain HRV demonstrated reliability across stable N2, SWS, and REM sleep, and remained reliable during disrupted sleep. These findings support the use of HRV during sleep as a tool for assessing cardiovascular health and risk stratification.NEW & NOTEWORTHY Heart rate variability (HRV) is a commonly employed indirect estimate of cardiac autonomic activity during sleep with limited reliability studies. Nocturnal frequency-domain HRV was reliable across differing stable sleep cycles of stage-2 (N2), slow-wave (SWS), and rapid-eye-movement (REM) sleep. Moreover, frequency- and time-domain HRV were reliable during stable and disturbed sleep, except SWS low-frequency HRV. Our finding supports nocturnal HRV as a potential tool for cardiovascular risk stratification.

Reliability of Heart Rate Variability during Polysomnographic Sleep

Spectral analysis of heart rate variability (HRV) is often used as a noninvasive index of cardiac sympathetic and/or parasympathetic activity during sleep. During controlled wake recordings, the low frequency (LF) component of HRV can be unreliable within experimental sessions and against other direct sympathetic measurements. In contrast, the high frequency (HF) component of HRV has higher reported reproducibility within controlled wake sessions. It remains unknown if the frequency component of HRV is reliable across sleep cycles within individuals during stable sleep. The purpose of the present study was to determine HRV reliability during stable stage II (N2) sleep, slow wave sleep (SWS) and rapid eye movement (REM) sleep. We hypothesized that both LF and HF components of HRV would be less reliable during REM sleep than during SWS and N2 sleep. Twenty‐seven participants (11 male, 16 female, 26±1 years, 27±1 kg/m2) were enrolled in the present study. Overnight polysomnography (PSG; NATUS, Middleton, WI) and continuous two‐lead electrocardiography (ECG) were recorded during an 8‐hour sleep opportunity. The nocturnal ECG recordings were imported into a custom software (WinCPRS, Absolute Aliens, Finland) for analysis of HRV via fast‐Fourier transformation function. Autonomic cardiac activity was quantified as LF (0.04‐0.15 Hz) and HF (0.15‐0.4 Hz) HRV. Two separate stable periods of sleep (range, 5‐10 min) absent of cortical arousal were selected from each sleep stage for comparison. Raw LF and HF HRV underwent logarithmic transformation due to non‐normal distribution. Statistical analysis included bivariate correlation of HRV across differing sleep stage cycles (α = 0.05). LF HRV was significantly correlated across two independent sleep cycles in N2 (r=0.694, p&lt;0.001, n=26), SWS (r=0.765, p&lt;0.001, n=25), and REM sleep (r=0.699, p&lt;0.001, n=20). Similarly, HF HRV was reliable across two independent sleep cycles in N2 sleep (r=0.839, p&lt;0.001, n=26), SWS (r=0.765, p&lt;0.001, n=25), and REM sleep (r=0.881 p&lt;0.001, n=21). Taken together, both LF and HF HRV measures were reliable across stable N2, SWS, and REM sleep. Our results support the reliability of frequency domain analysis of HRV during key PSG sleep stages within a single night, but further research across nights is warranted.

The height and LnLF power cover the most of sex differences during orthostasis

The sex differences in autonomic regulation of cardiovascular and respiratory system, as one of the key physiological mechanisms of disease, till now remain underexplored. We hypothesized that cardiovascular and respiratory systems share the same autonomic mechanisms, represented by heart rate variability (HRV) indexes, opposing the effect of orthostasis, which are partially different between sexes.The 147 participants, 78 men and 69 women were recruited from the student population of local University for the research study. The low and high frequency heart rate variability (LF and HF HRV) was computed from ECG recording in the sitting position for 5 minutes of resting and slow breathing (6 breaths per minute) stages. The sitting position was used according to requirement of spirometry system. The tidal volume (TV) and respiratory rate (RR) were recorded for one minute at the end of each stage. Systolic and diastolic blood pressure (SBP and DBP) were measured with automatic digital sphygmomanometer (OMRON EVOLV, Japan). Two‐way repeated measures MANOVA and MANCOVA (SPSS 22) were used to test for effects of orthostasis and sex on HR, SBP, DBP, HRV variables, TV, RR, and MV. Multiple stepwise regression analysis was used to determine predictors of cardiovascular and respiratory variables. Written informed consent was obtained from each participant.In the current study we found significant main effects of orthostasis on HR, DBP, LnLF, LnHF (P&lt;0.001 for each), and significant main effects of sex on HR, SBP, LnLF, TV, and MV (for HR P=0.004, for LnLF P=0.006, for the rest P&lt;0.001). Follow the significant sex by orthostasis interaction we found that RR increased only for men upon standing but not for women.Multiple stepwise linear regression analysis revealed that when adjusting for potentially confounding variables, the change of cardiovagal‐mediated LnHF power (Figure 1A) was an independent predictor of HR and RR response to orthostasis (Table 1, Models 1 and 2). Women was an independent predictor of dRR, while Women by dLnLF interaction determined dHR, showing that LnLF, indicating according to our hypothesis, baroreflex‐mediated sympathoinhibition, contribute to HR response in women (Fig. 1B).The BMI by LnLF power interaction was a negative predictor of resting RR (Table 1, Model 3). It is suggested that baroreflex‐mediated sympathoinhibition contribute to respiratory central pattern generator particularly in people with increased BMI. The same interaction was a positive predictor of TV (Table 1, Model 4) indicating that increased time of respiratory cycle accompines greater TV.The comparisons of the similar models with and without dummy variables indicating “Women”, revealed that the dummy variable replaced “Height” or “LnLF”, suggesting that differences in both independent variables relate to mechanisms controlling cardiorespiratory system specific to female gender.In conclusion, cardiovagal‐mediated LnHF HRV power controls both HR and RR and determines their response to orthostasis. The differences in height and LnLF power cover the most of the sex difference in mechanisms controlling cardiovascular and respiratory variables and their response to orthostasis.

The Cardiorespiratory Coupling as a Background for Blood Pressure Decrease

The role of cardiorespiratory coupling cannot be overemphasized. Cardiorespiratory coupling has many potential benefits in maintaining homeostasis. One of manifestation of cardiorespiratory coupling is respiratory sinus arrhythmia observed at respiratory rate 6 breaths/ minute. Multiple factors, including mechanical coupling, are responsible for the fluctuation of HR and BP. However, the fine mechanisms of the autonomic, cardiovascular, and respiratory interactions till now remains unclear.A total of 156 international students were recruited from the V.N. Karazin Kharkiv National University. The sitting position was taken as a baseline according to requirements of the spirometry system. The ECG was continuously recorded at the rest and during slow breathing at 6 breaths/minute. The respiratory rate (RR) and tidal volume (TV) were recorded at the end of each stage for one minute using SPIROCOM pc based systems (XAI‐Medica, Ukraine). Systolic and diastolic blood pressure (SBP and DBP) were recorded by means automatic digital sphygmomanometer (OMRON EVOLV, Japan). The low and high frequency heart rate variability (LF and HF HRV) power were computed with CardioLab CS by fast Fourier transforming. The repeated measures MANOVA with Bonferroni correction (SPSS 22) was used to test for effects of slow breathing on HR, SBP, DBP, LnLF, LnHF, tidal volume (TV), minute ventilation (MV), and RR variables. Predictors of HR, SBP, DBP, TV, MV., and RR to slow breathing were determined using stepwise multiple linear regression analysis. Written informed consent was obtained from each participant.In the current study the slowing respiratory rate to 6 breaths/min increased HR (P&lt;0.001) (not shown), decreased SBP (P&lt;0.001), decreased DBP (P=0.003), increased LnLF (P&lt;0001), increased TV (P&lt;0.001), and decreased RR (not shown, Р&lt;0.001). The stepwise multiple linear regression analysis revealed that at rest HR and RR were negatively associated with LnHF power (Table 1, P&lt;0.001 for both), while at slow breathing stage the HR was negatively associated with both LnHF and LnLF power (Table 2, P&lt;0.001 and P=0.004, respectively). If the HF power is widely used as an index of cardiovagal activity, interpretation of the LF power is more controversal. We proceeded from our hypothesis that LF HRV power is a measure of baroreflex‐mediated sympathoinhibition. At rest both SBP and DBP were positively associated with LnLF by LnHF interaction, while at slow breathing stage they were negatively associated only with LnLF power. The resting TV and MV were positively associated with LnLF power, also, the MV with LnHF by height and BMI interaction. But at slow breathing stage only the height and BMI were independent variables remaining in these models (Table 2, Models 4 and 5).Taken together, these findings indicate that the same autonomic variables control respiratory function in parallel with cardiovascular system.

Impact of Gonadectomy on Sex‐Selective Dysregulation of Cardiovascular Function Resulting From In UteroExposure to Dexamethasone

Prenatal insults leading to increased fetal glucocorticoid exposure can sex‐selectively impact cardiovascular function in adulthood. In support of this, we have shown that when pregnant rat dams are treated with the glucocorticoid, dexamethasone (DEX), for the last 4 days of gestation, female‐specific changes resulting in enhanced pressor and heart rate (HR) responses to stress occur in adult offspring. Moreover, we demonstrated that females exposed to DEX in uteroshow altered autonomic function compared to vehicle‐exposed females. This is characterized by a reduced high frequency (HF) power component of heart rate variability (HRV) in DEX‐exposed rats, suggesting a lower reliance on parasympathetic drive. The present study evaluated the degree to which the sex‐specific changes in autonomically‐driven cardiovascular responses are due to activational effects of gonadal steroid hormones. Pregnant dams were administered DEX (0.4mg/kg per day, s.c.) or vehicle on gestation days 18‐21. This resulted in a significant reduction in birthweight in DEX‐exposed males and females. At 8 weeks, rats underwent a gonadectomy (GDX) or sham surgery, or remained intact, and at 10 weeks rats were instrumented with radiotelemetric transmitters for direct recording of arterial pressure, HR, and HRV in conscious, freely moving male and female rats. At 11‐12 weeks rats were placed in a restraint tube for 20 minutes, followed by a 3‐hour recovery period, to assess whether GDX alters the sex‐specific stress responses in DEX‐exposed offspring. Restraint‐stress testing was performed on diestrus in intact and sham females, and absence of cycling in GDX females was confirmed via cytological analysis. We demonstrate that intact females, but not males, that were exposed to DEX in utero exhibit an exaggerated pressor response to restraint, as compared to vehicle‐exposed females. We found that GDX did not alter stress‐responsive MAP in males regardless of prenatal treatment, suggesting testosterone does not play a role in acute cardiovascular stress responses in adult rats. In vehicle‐exposed females, when compared to intact, both sham and GDX surgery resulted in an exaggerated pressor response to restraint. However, in females that were prenatally exposed to DEX, there was no difference in the pressor response to restraint between intact, sham, and GDX rats. This suggests that the exaggerated pressor response observed in DEX females compared to males is not due to activational effects of estradiol. GDX was shown to have opposing effects on HRV in males and females, with no influence of prior DEX. In females, GDX resulted in a tendency toward reduced HF (p=0.065) and low frequency (LF, p=0.074) power component of HRV, whereas males showed a significant increase in HF (p=0.044) and a tendency toward increased LF (0.051). Taken together, activational effects of gonadal steroids appear to impact HRV, but not acute cardiovascular responses to stress. It may be that gonadal steroids act at an organizational level to mediate the sex difference observed in rats exposed to DEX in utero. Future studies to identify the mechanisms by which prenatal dexamethasone produce long‐term changes in cardiovascular function will be important for better understanding the sex‐specific consequences of prenatal programming over the lifespan.

Five-Year PTSD Symptom Remission in Two Patients Following Treatment With Rivastigmine.

The beneficial effect of rivastigmine, an acetylcholinesterase inhibitor (AChEi), which increases levels of acetylcholine (ACh), was first reported in 2013. This paper replicates those findings and reports sustained symptom remission. The high-frequency (HF) component of heart rate variability (HRV) is a measure of cholinergic withdrawal and was measured using a Zephyr Bioharness HR monitor, pre- and post-commencement of treatment. Data analysis was performed using Kubios HRV software. PTSD symptom severity was assessed using the Post-Traumatic Checklist-Civilian (PCL-C). Low HF HRV was observed in both patients before rivastigmine treatment and reductions in PCL-C scores paralleled increases in HF HRV values. Follow-up revealed low HF HRV values in both patients despite PCL-C scores indicating remission. Sympathetic nervous system hyperactivity was observed in one patient, just before a suicide attempt. Following rivastigmine treatment, the patient had no further suicidal ideation or attempts. Another patient reported worsening of her PTSD symptoms in the peri-menstrual period, which was abolished by rivastigmine. She also experienced symptom relapse following prolonged infections. Low HF HRV has been reported in PTSD patients, but findings have been inconsistent. Cholinergic withdrawal could explain the disturbances in sleep, learning, and memory seen in PTSD patients. The relapse of symptoms following prolonged infection implicates the immune system as a possible initiator of the disorder. ACh and estrogen have anti-inflammatory properties, supporting a possible role of inflammation in initiating PTSD. The effect of rivastigmine treatment should be tested in properly controlled clinical trials.

Parasympathetic cardiac control during attentional focus and worry in major depressive disorder

Worry, which refers to uncontrollable chains of thoughts and images with negative affective load, is a transdiagnostic symptom of various mental disorders including major depressive disorder (MDD). Current theories relate excessive worry to deficient top-down control of automatically occurring perseverative thinking. This study investigated parasympathetic cardiac control in MDD in the context of worry and cognitive control. Heart rate variability (HRV) was recorded, in the high frequency (HF) and low frequency (LF) bands, in 36 MDD patients and 36 healthy controls while they performed a breathing focus task. The task included two phases during which participants' ability to concentrate on their breathing was assessed before and after an instructed worry phase. In addition to higher self-reported worry, MDD patients exhibited lower HF and LF HRV at rest, and lower LF HRV during the task than controls. MDD was also associated with impaired breathing concentration ability, more negative and neutral thought intrusions, more negative mood during breathing focus and increased stress during instructed worry. In the total sample, LF HRV correlated negatively with self-reported worry and negative thought intrusions, and positively with mood ratings. The reduction of HRV confirms the notion of low parasympathetic cardiac control in MDD. Moreover, low HRV represents a correlate of blunted prefrontal activity and impaired cognitive control that characterize the disorder. Impaired cognitive control may exacerbate worry, which is in turn involved in the genesis of aversive emotional states and maintenance of MDD.

The cardiac autonomic response to acute psychological stress in type 2 diabetes.

Impaired cardiac autonomic control is common among people with type 2 diabetes. The autonomic nervous system and its regulatory influence on the cardiovascular system also play a key role in the physiological response to psychosocial stressors. It is unclear whether the disease-related impairment of cardiac autonomic control in people with type 2 diabetes affects the stress response. The aim of this study was therefore to examine the cardiac autonomic and the psychological stress response of people with type 2 diabetes compared to healthy control participants. We used the trier social stress test to induce stress in n = 51 participants with type 2 diabetes and n = 47 healthy controls. We assessed heart rate (HR) and heart rate variability (HRV) using six ECG samples before, during and after the stress test. We measured participants' psychological stress response using visual analogue scales. Longitudinal multilevel models showed an attenuated HR increase in response to the stress test combined with a slower HR recovery after the stress test, in people with type 2 diabetes. This pattern was accompanied by significantly lower low frequency HRV but no differences in high frequency HRV between the groups. Additionally, people with type 2 diabetes showed an increased level of self-reported psychological tension 45 minutes after the stress test. The impairment of the autonomic nervous system found in people with type 2 diabetes is reflected in the HR response to stress-but not in the HRV response-and partially mirrored in the psychological stress response. Our results underline the importance of considering the interplay of psychosocial stress and disease-related changes in the physiological stress response system in research and treatment of type 2 diabetes.

Effects of cardiovascular arousal on emotional experience.

Studies of arousal and emotion show that generalized physiological arousal can enhance emotional experience for a range of different emotions. Other research shows that different emotions may be associated with specific patterns of physiological reactivity. Together these findings suggest that while nonspecific autonomic activation can be sufficient in the generation of emotion, specific patterns of reactivity may appear once the emotion is established. This study aimed to test this hypothesis by examining the effects of generalized arousal on emotional experience, as well as the physiological responses associated with positive and negative emotions. One hundred and nine participants either sat or stood during the viewing of positive and negative film clips while emotion ratings and cardiorespiratory measures were taken. Those who stood during the videos reported greater levels of emotion than those who sat, indicating that generalized arousal due to standing heightened emotional experience. In addition, participants exhibited greater high-frequency heart rate variability and lower respiration rate during the negative video than the positive video, indicating that physiological reactivity differed between the positive and negative emotions. These results suggest that while patterns of physiological reactivity may be specific to individual emotions, nonspecific arousal is sufficient to enhance diverse emotions.

Emotional distress and pain catastrophizing predict cue-elicited opioid craving among chronic pain patients on long-term opioid therapy

BackgroundIndividuals who use illicit substances exhibit cue-elicited craving and autonomic cue-reactivity when exposed to cues associated with past drug use. However, little is known about this phenomenon among chronic pain patients on long-term opioid therapy (LTOT). Negative cognitive-emotional reactivity in general (e.g., distress) and cognitive-emotional reactivity specific to pain (e.g., pain catastrophizing) might drive cue-reactivity independent of pain severity. Here we examined emotional distress and pain catastrophizing as predictors of cue-reactivity among a sample of chronic pain patients receiving LTOT. We also tested whether associations between distress, catastrophizing, and cue-reactivity differed as a function of opioid misuse status. Materials and methodsPatients receiving LTOT (N = 243) were classified as exhibiting aberrant behavior consistent with opioid misuse (MISUSE+, n = 145) or as using opioids as prescribed (MISUSE-, n = 97). Participants completed assessments of pain catastrophizing and emotional distress and then participated in an opioid cue-reactivity task one week later. Cue-elicited opioid craving and autonomic cue-reactivity were measured with craving ratings and high-frequency heart rate variability (HRV), respectively. ResultsDistress and catastrophizing predicted cue-elicited craving and HRV, whereas pain severity did not. Misuser status moderated the relationship between emotional distress and self-reported craving, such that higher levels of distress predicted craving among the MISUSE+ group, but not among the MISUSE- group. No moderating effects were found for catastrophizing. ConclusionsFindings suggest that although opioids are prescribed for analgesia, the exacerbating influence of negative cognitive-emotional reactivity, both in general and specific to pain, on cue-elicited opioid craving extends beyond the effects of pain severity alone.

A pilot study investigating the relationship between heart rate variability and blood pressure in young adults at risk for cardiovascular disease

BackgroundCardiovascular disease is one of the leading causes of death globally with hypertension being a primary cause of premature death from this disease process. Individuals with a family history of cardiovascular disease and hypertension are at a greater risk for developing the same sequela. Autonomic cardiac control is important in the level of cardiac function. One intervention that is effective in improving cardiovascular function is heart rate variability biofeedback training. The purpose of our study was to determine the effectiveness of heart rate biofeedback training on HRV and blood pressure in individuals with a family history of cardiovascular disease.MethodsThirty-four participants (76.5% female, 22.7 ± 4.3 years) completed a baseline assessment and training using an established short-term HRV protocol followed by two weeks of at-home paced breathing employing a smartphone application. The participants were then reassessed in a biofeedback clinic.ResultsThe participants physiological measures showed a significant increase in means between pre and post intervention of SDNN (t (32) = 2.177, p =.037) and TP, (t (32) = 2.327 p = .026). Correlation noted a medium effect on diastolic blood pressure and high frequency heart rate variability, F, r = .41, n =33, p < .05. A multiple regression with all predictor variables in the model found no significance with diastolic and systolic blood pressure.ConclusionsThe findings from this pilot study demonstrated that a two-week paced breathing intervention may assist in reducing heart rate and diastolic blood pressure while improving heart rate variability.

Early life stress and autonomic response to acute mental stress in individuals with coronary heart disease.

Early life stress (ELS) has been associated with an increased risk of cardiovascular disease. We examined whether ELS was associated with autonomic function and stress reactivity among individuals with coronary heart disease (CHD). We included patients with stable CHD from two parallel studies, the Mental Stress Ischemia Prognosis Study (MIPS) and the Myocardial Infarction and Mental Stress Study 2 (MIMS2), and assessed ELS using the Early Trauma Inventory-Self-Report-Short Form. Participants underwent a laboratory-based mental stress task while undergoing ambulatory electrocardiographic monitoring. We used multivariate linear regression models to estimate the associations between ELS and heart rate variability (HRV; low frequency [LF], high frequency [HF], and LF and HF [LH] ratio). The analytic sample included 405 MIPS and 284 MIMS2 participants. Most participants endorsed at least one experience of ELS (92.2%). Although we did not observe associations between ELS and HRV outcomes in the overall sample, ELS was associated with lower LH ratio HRV during recovery in the posttraumatic stress disorder (PTSD) subgroup, ELS x PTSD interaction, p=.041. In the MIMS2 subgroup, ELS was associated with lower resting period LF HRV, =-0.16 ln ms2 ; 95% CI [-0.31, -0.02]. Exposure to physical trauma was associated with decreased HF HRV overall reactivity only among participants with high to moderate depressive symptoms, =-0.52 ln ms2 vs. =0.01 ln ms2 , p=.013. Overall, heterogeneous associations between ELS and HRV emerged, suggesting the need for additional research regarding longer-term ambulatory HRV.

Enhancing cognitive restructuring with concurrent fMRI-guided neurostimulation for emotional dysregulation–A randomized controlled trial

BackgroundTransdiagnostic clinical emotional dysregulation is a key component of many mental health disorders and offers an avenue to address multiple disorders with one transdiagnostic treatment. In the current study, we pilot an intervention that combines a one-time teaching and practice of cognitive restructuring (CR) with repetitive transcranial magnetic stimulation (rTMS), targeted based on functional magnetic resonance imaging (fMRI). MethodsThirty-seven clinical adults who self-reported high emotional dysregulation were enrolled in this randomized, double-blind, placebo-controlled trial. fMRI was collected as participants were reminded of lifetime stressors and asked to downregulate their distress using CR tactics. fMRI BOLD data were analyzed to identify the cluster of voxels within the left dorsolateral prefrontal cortex (dlPFC) with the highest activation when participants attempted to downregulate, versus passively remember, distressing memories. Participants underwent active or sham rTMS (10 Hz) over the left dlPFC target while practicing CR following emotional induction using recent autobiographical stressors. ResultsReceiving active versus sham rTMS led to significantly higher high frequency heart rate variability during regulation, lower regulation duration during the intervention, and higher likelihood to use CR during the week following the intervention. There were no differences between conditions when administering neurostimulation alone without the CR skill and compared to sham. Participants in the sham versus active condition experienced less distress the week after the intervention. There were no differences between conditions at the one-month follow up. ConclusionThis study demonstrated that combining active rTMS with emotion regulation training for one session significantly enhances emotion regulation and augments the impact of training for as long as a week. These findings are a promising step towards a combined intervention for transdiagnostic emotion dysregulation.

Beyond mindfulness: Arousal-driven modulation of attentional control during arousal-based practices.

Here we report meditative techniques, which modulate attentional control by arousal-driven influences and not by monitoring continuous thought processes as during mindfulness-related practices. We focus on Vajrayana (Tantric Buddhism) practices, during which a sequence of generation (self-visualization as a deity - Yidam) or completion with sign (inner heat -Tummo) stages necessarily precedes non-dual awareness (NDA) Tantric Mahamudra. We compared the electrocardiographic and electroencephalographic correlates of Mahamudra performed after rest (non-Tantric Mahamudra) with Mahamudra performed after Yidam (Tantric Mahamudra) in 16 highly experienced Vajrayana practitioners, 10 of whom also performed Tummo. Both Yidam and Tummo developed the state of PNS withdrawal (arousal) and phasic alertness, as reflected by HF HRV decreases and Alpha2 power increases, later neurophysiologically employed in Tantric Mahamudra. The latter led to the unique state of high cortical excitability, “non-selective” focused attention, and significantly reduced attentional control, quantified by power reductions in all frequency bands, except Theta. In contrast, similar to mindfulness-related practices, non-Tantric Mahamudra was performed in a state of PNS dominance (relaxation), tonic alertness, and active monitoring, as suggested by Alpha1 power increases and less pronounced decreases in other frequency bands. A neurobiological model of meditation is proposed, differentiating arousal-based and mindfulness-related practices.

Heart rate variability, serum cortisol levels and temperament in a sample of workers exposed to occupational stress: a preliminary report

ABSTRACT Work-related stress is an emerging risk for psychiatric occupational disorders including Adjustment Disorders (AD). The aim of this study was to investigate in workers exposed to occupational stress suffering from AD about putative indices of stress and mental health resilience such as serum cortisol (seC) levels, Heart Rate Variability (HRV) and affective temperaments. We consecutively recruited 15 male and 15 female AD patients between workers evaluated for occupational stress at an Italian Occupational Medicine Unit. SeC levels were measured by specific immunoassay. HRV indices were recorded using Task Force® Monitor system (CNSystems, Graz, Austria). Specific questionnaires were used to measure perceived and occupational stress, psychopathological symptoms and temperament. Women presented higher levels of occupational stress, higher High-Frequency HRV (HF-HRV) and lower Low-Frequency HRV (LF-HRV) than men. SeC levels were positively correlated with LF-HRV values and negatively with HF-HRV values. The LF/HF ratio resulted to be inversely correlated with the score of Harm Avoidance temperament dimension and directly with the score of Reward Dependence temperament dimension. In conclusion, in AD patients exposed to occupational stress high seC levels and reward dependence appear to be associated with a pattern of HRV reflecting less mental health resilience.