Heart Rate Variability (HRV) serves as an objective correlate of distress and symptom burden in multiple sclerosis

Background

Autonomic nervous system (ANS) dysfunction is frequently seen in people living with multiple sclerosis (MS). Heart rate variability (HRV) is an easy and objective index for evaluating ANS functioning, and it has been previously used to explore the association between ANS and the experience of symptom burden in other chronic diseases. Given ANS functioning can be influenced by physical and psychological factors, this study investigated whether emotional distress and/or the presence of ANS dysfunction is associated with symptom severity in people living with MS.

Methods

Participants with MS and healthy controls (HC) with no history of cardiac conditions were recruited to self-collect HR data sampled from a chest strap HR monitor (PolarH10). Short-term HR signal was collected for five minutes, and time and frequency HRV analyses were performed and compared between groups. HRV values were then compared to self-reported distress (Kessler Psychological Distress Scale) and MS participants' self-reported measures of symptom burden (SymptoMScreen).

Results

A total of n = 23 adults with MS (51 ± 12 years, 65 % female, median Patient Determined Disease Steps [PDDS]: 3.0) and n = 23 HCs (43 ± 18 years, 40 % female) completed the study procedures. All participants were able to complete the chest strap placement and HR data capture independently. Participants with MS, compared to the HC participants, had a significantly lower parasympathetic activation as shown by lower values of the root mean square of successive differences between normal heartbeats (RMSSD: 21.86 ± 9.84 vs. 43.13 ± 20.98 ms, p = 0.002) and of high-frequency (HF) power band (HF-HRV: 32.69 ± 12.01 vs. 42.39 ± 7.96 nu, p = 0.016), indicating an overall lower HRV in the MS group. Among individuals with MS, HF-HRV was significantly correlated with the severity of self-reported MS symptoms (r = -0.548, p = 0.010). Participants with MS also reported higher levels of distress compared to HC participants (18.32 ± 6.05 vs. 15.00 ± 4.61, p = 0.050), and HRV correlated with the severity of distress in MS participants (r = -0.569, p = 0.007). A significant mediation effect was also observed, with emotional distress fully mediating the association between HRV and symptom burden.

Conclusions

These findings suggest the potential for ANS dysfunction, as measured by HRV (i.e., lower value of HF power), to be utilized as an objective marker of symptom burden in people living with MS. Moreover, it is apparent that the relationship between HRV and symptom burden is mediated by emotional distress.

Heart rate variability associated with grey matter volumes in striatal and limbic structures of the central autonomic network

Previous neuroimaging studies have highlighted the functional neural correlates of cardiac vagal activity, providing convergent evidence that the cardiac vagal function is controlled by a number of brain regions in the central autonomic network (CAN). However, it remains largely unknown whether the underlying anatomical basis of those identified regions are associated with individual difference in vagal function. To address the above issue, this study used a large sample of healthy subjects (n = 185) and voxel-based morphometry (VBM) analysis to verify brain morphometry associated with vagal control and the associations varied as a function of gender and age. Our results showed that high frequency component of heart rate variability (HF-HRV) was negatively correlated with grey matter volumes in the right putamen, caudate, amygdala, insula, superior temporal gyrus, temporal pole, and parahippocampal gyrus, demonstrating brain morphological variation in the right-sided striatal and limbic structures of the CAN associated with individual difference in cardiac vagal function. Additionally, gender and age effects on the relationship between cardiac vagal control and brain morphometry were not significant in the current dataset. These findings underscore the importance of striatal and limbic structures in parasympathetic control, and shed light on the underlying anatomical substrates of cardiac vagal activity.

Heart rate variability changes and emotion regulation abilities in short- and long-term abstinent alcoholic individuals

INTRODUCTION

Difficulties in identifying and regulating emotion are recognized as major factors of relapse in alcohol use disorders (AUD). This study aimed to evaluate the differences of emotion regulation processes in AUD patients with short-term (STA, less than one month) and long-term abstinence (LTA, at least six months) by recording the high frequency of Heart Rate Variability (HF-HRV) in response to emotional and neutral stimuli.

METHOD

Emotional induction constituted the presentation of highly emotional and neutral pictures (IAPS data base) presenting human interactions. HF-HRV was recorded before (at rest), during (pictures) and after emotional induction (recovery).

RESULTS

The results showed higher phasic HF-HRV in the STA group in comparison to the LTA and C groups for negative, positive and neutral stimuli. In the LTA group, we observed a normalization of HRV, in response to emotional stimuli. However, for negative valence stimuli in the recovery period, LTA participants are no more different from STA group. A main positive correlation was observed for both patient groups between craving scores and increased HF-HRV during and after the emotion induction.

CONCLUSION

The data support the hypothesis of emotion regulation impairment after STA but also show a partial improvement with prolonged abstinence. This impairment in patients may correspond to the maintenance of negative feedback that accentuates the difficulties in the emotional physiological process and limits the ability to engage in or maintain other processes. HF-HRV is a good indicator of emotion regulation processes related to the intensity of the craving even after long-term abstinence.

Attachment and emotion regulation in middle childhood: changes in affect and vagal tone during a social stress task

In middle childhood, more securely attached children show better emotion regulation when assessed as general tendencies (e.g. coping style), but studies looking at emotion in response to specific stressors have revealed mixed results. This study examined how attachment security, avoidance, and ambivalence - assessed with a story stem task (99 children, 9-11 years old) - relate to dynamic indices of affective and autonomic responses (baseline, reactivity, recovery). Reports of positive and negative affect, and high-frequency heart rate variability (HF-HRV), were assessed during a social stressor task. Securely attached children did not show reactivity effects, although they did show greater recovery of positive affect after the task ended. Avoidant children showed both less reactivity and recovery of negative affect, suggesting a dampened emotional response. Ambivalent children showed more reactivity and more recovery of negative affect. Autonomic response changes were only evident for ambivalent children, who showed less suppression of HF-HRV variability under stress.

Guanfacine alters the effect of stress and smoking on heart rate variability in regular daily smokers

BACKGROUND

We had previously demonstrated that guanfacine, an α2a-adrenergic agonist, attenuated the effect of stress on smoking-lapse behavior in regular daily smokers. Heart rate variability (HRV), a measure of vagal activity, may be a potential mechanism underlying the relationship between stress, smoking, and relapse.

METHODS

We examined whether guanfacine (0 mg/day vs. 3 mg/day; n = 26) altered changes in high-frequency heart rate variability (HF-HRV) following stress and ad-lib smoking using a validated laboratory analogue of smoking-lapse behavior. All participants completed a parent study evaluating the effects of guanfacine on stress-precipitated smoking. Each subject completed two laboratory sessions assessing the effects of guanfacine on HF-HRV following stress imagery (vs. neutral imagery; order counterbalanced) and smoking.

RESULTS

Results demonstrated that guanfacine did not increase tonic levels of HF-HRV relative to placebo. Following the stress versus neutral imagery manipulation (prior to ad-lib smoking), there were no significant changes in HF-HRV in the placebo group. In contrast, guanfacine increased phasic HF-HRV following stress imagery and decreased HF-HRV following neutral imagery. Ad libitum smoking following both the stress and neutral conditions decreased HF-HRV in the placebo group across both imagery conditions. In contrast, guanfacine attenuated stress- and smoking-related decreases in phasic HF-HRV relative to the neutral imagery condition.

CONCLUSIONS

This is the first demonstration that a noradrenergic target altered dynamic changes in HF-HRV in response to stress and smoking, suggesting that guanfacine alters HF-HRV response to stress. Findings support current theories which suggest that phasic changes in HRV are an important marker of the stress response.

Time-varying correlations between delta EEG power and heart rate variability in midlife women: the SWAN Sleep Study

No studies have evaluated the dynamic, time-varying relationship between delta electroencephalographic (EEG) sleep and high frequency heart rate variability (HF-HRV) in women. Delta EEG and HF-HRV were measured during sleep in 197 midlife women (M(age)  = 52.1, SD = 2.2). Delta EEG-HF-HRV correlations in nonrapid eye movement (NREM) sleep were modeled as whole-night averages and as continuous functions of time. The whole-night delta EEG-HF-HRV correlation was positive. The strongest correlations were observed during the first NREM sleep period preceding and following peak delta power. Time-varying correlations between delta EEG-HF-HRV were stronger in participants with sleep-disordered breathing and self-reported insomnia compared to healthy controls. The dynamic interplay between sleep and autonomic activity can be modeled across the night to examine within- and between-participant differences including individuals with and without sleep disorders.