Heart Rate Variability (HRV) and Posttraumatic Stress Disorder (PTSD): A Pilot Study

Altered resting-state functional connectivity of basolateral and centromedial amygdala complexes in posttraumatic stress disorder

The amygdala is a major structure that orchestrates defensive reactions to environmental threats and is implicated in hypervigilance and symptoms of heightened arousal in posttraumatic stress disorder (PTSD). The basolateral and centromedial amygdala (CMA) complexes are functionally heterogeneous, with distinct roles in learning and expressing fear behaviors. PTSD differences in amygdala-complex function and functional connectivity with cortical and subcortical structures remain unclear. Recent military veterans with PTSD (n=20) and matched trauma-exposed controls (n=22) underwent a resting-state fMRI scan to measure task-free synchronous blood-oxygen level dependent activity. Whole-brain voxel-wise functional connectivity of basolateral and CMA seeds was compared between groups. The PTSD group had stronger functional connectivity of the basolateral amygdala (BLA) complex with the pregenual anterior cingulate cortex (ACC), dorsomedial prefrontal cortex, and dorsal ACC than the trauma-exposed control group (p<0.05; corrected). The trauma-exposed control group had stronger functional connectivity of the BLA complex with the left inferior frontal gyrus than the PTSD group (p<0.05; corrected). The CMA complex lacked connectivity differences between groups. We found PTSD modulates BLA complex connectivity with prefrontal cortical targets implicated in cognitive control of emotional information, which are central to explanations of core PTSD symptoms. PTSD differences in resting-state connectivity of BLA complex could be biasing processes in target regions that support behaviors central to prevailing laboratory models of PTSD such as associative fear learning. Further research is needed to investigate how differences in functional connectivity of amygdala complexes affect target regions that govern behavior, cognition, and affect in PTSD.

Comparative Study of Heart Rate Variability in Patients with Schizophrenia, Bipolar Disorder, Post-traumatic Stress Disorder, or Major Depressive Disorder

Objective

Heart rate variability (HRV) changes as a function of psychiatric illness. This study aimed to evaluate HRV among patients with various psychiatric disorders.

Methods

The present study recruited patients with schizophrenia (n=35), bipolar disorder (n=41), post-traumatic stress disorder (PTSD; n=34), or major depressive disorder (n=34) as well as healthy controls (n=27). The time-domain analysis (the standard deviation of all RR intervals [SDNN] and the square root of the mean squared differences of successive normal sinus intervals [RMSSD]), the frequency-domain analysis (very low frequency, low frequency [LF], high frequency [HF], and total power [TP]), and a non-linear complexity measure the approximate entropy were computed.

Results

SDNN and HF were significantly reduced in patients with schizophrenia compared with healthy controls. SDNN, RMSSD, TP, LF, and HF were significantly reduced in bipolar patients compared with healthy controls. HF was significantly reduced in PTSD patients compared with healthy controls.

Conclusion

Our findings indicate that HRV is not sufficiently powerful to discriminate among various psychiatric illnesses. However, our results suggest that HRV, particularly HF, could be used as a tool for discriminating between psychiatric patients and healthy controls.

A possible mechanism for PTSD symptoms in patients with traumatic brain injury: central autonomic network disruption

Patients with traumatic brain injuries (TBI) often develop post traumatic stress disorder (PTSD). This syndrome, defined and diagnosed by psychological and behavioral features, is associated with symptoms such as anxiety and anger with an increase of arousal and vigilance, as well as flashbacks and nightmares. Many of these features and symptoms observed in PTSD may be in part the result of altered autonomic nervous system (ANS) activity in response to psychological and physical challenges. Brain imaging has documented that TBI often induces white matter damage to pathways associated with the anterior limb of the internal capsule and uncinate fasciculus. Since these white matter structures link neocortical networks with subcortical and limbic structures that regulate autonomic control centers, injury to these pathways may induce a loss of inhibitory control of the ANS. In this review, the autonomic features associated with PTSD are discussed in the context of traumatic brain injury. We posit that TBI induced damage to networks that regulate the ANS increase vulnerability to PTSD. The means by which the vulnerability can be measured and tested are also discussed.

The Promise of Heart Rate Variability Biofeedback: Evidence-Based Applications

Heart rate variability biofeedback has enjoyed increased popularity in recent years. In this review, empirical evidence from multiple sources is presented from the point of view of possible mechanisms of effect. While more research is clearly needed, the data thus far are certainly promising.

Heart Rate Variability and Posttraumatic Stress Disorder

The psychophysiology of posttraumatic stress disorder (PTSD) points towards autonomic dysregulation—specifically, elevated sympathetic response and attenuated parasympathetic response. In view of this, heart rate variability (HRV) biofeedback has been applied and tested as a treatment for PTSD. Review of existing published research suggests that HRV biofeedback seems promising as a treatment for PTSD, both in significantly alleviating the symptoms and in improving cognition for those suffering from PTSD. Drop-out rate is low, and inexpensive and portable HRV biofeedback devices such as the Stress Eraser make it a viable alternative to traditional treatment such as prolonged exposure therapy (PET), cognitive behavior therapy (CBT) and cognitive processing therapy (CPT). More recent research has also shown that combining HRV biofeedback with CBT, PET, and Acceptance and Commitment Therapy (ACT) improved the efficacy of these therapies in treating PTSD. More larger-scale and rigorous controlled trials are needed to confirm these outcomes.

They know their trauma by heart: an assessment of psychophysiological failure to recover in PTSD

BACKGROUND

Posttraumatic stress disorder (PTSD) develops following exposure to atraumatic event and is characterized by persistent intense reactivity to trauma related cues. Equally important, but less studied, is the failure to restore physiological homeostasis after these excessive reactions. This study investigates psychophysiological markers of sustained cardiac activity after exposure to reminders of traumatic event in PTSD patients.

METHODS

Participants passively listened to neutral and personal traumatic event while electrocardiogram was continuously recorded. Heart rate (HR) and heart rate variability (HRV) were analyzed in 19 PTSD patients and 16 trauma-exposed controls.

RESULTS

Both PTSD patients and trauma exposed controls exhibited a significant increase in HR to the exposure of their personal trauma. PTSD patients sustained the increase of HR while controls recovered to basal levels. In PTSD patients, sustained HR was positively associated with re-experiencing symptoms. The PTSD group also showed a reduced HRV (a measure of parasympathetic influence on the heart) during personal trauma exposure and lack of recovery.

LIMITATIONS

The sample size was small and PTSD patients were under medication.

CONCLUSIONS

Our findings provide an experimental account of the failure of PTSD patients to exhibit physiological recovery after exposure to trauma-related stimuli. PTSD patients exhibited a sustained tachycardia with attenuation of HRV that persisted even after cessation of the stressor. Re-experiencing symptoms facilitated engagement in the trauma cues, suggesting that, in their daily-life, patients most likely present repeated episodes of sustained over-reactivity, which may underpin the emotional dysregulation characteristic of PTSD.

Peak high-frequency HRV and peak alpha frequency higher in PTSD

Posttraumatic stress disorder (PTSD) is difficult to treat and current PTSD treatments are not effective for all people. Despite limited evidence for its efficacy, some clinicians have implemented biofeedback for PTSD treatment. As a first step in constructing an effective biofeedback treatment program, we assessed respiration, electroencephalography (EEG) and heart rate variability (HRV) as potential biofeedback parameters for a future clinical trial. This cross-sectional study included 86 veterans; 59 with and 27 without PTSD. Data were collected on EEG measures, HRV, and respiration rate during an attentive resting state. Measures were analyzed to assess sensitivity to PTSD status and the relationship to PTSD symptoms. Peak alpha frequency was higher in the PTSD group (F(1,84) = 6.14, p = 0.01). Peak high-frequency HRV was lower in the PTSD group (F(2,78) = 26.5, p < 0.00005) when adjusting for respiration rate. All other EEG and HRV measures and respiration were not different between groups. Peak high-frequency HRV and peak alpha frequency are sensitive to PTSD status and may be potential biofeedback parameters for future PTSD clinical trials.

Heart rate variability and its neural correlates during emotional face processing in social anxiety disorder

The monitoring and regulation of one's own physiological reactions and cardioregulatory abnormalities are central to the aetiology and maintenance of social anxiety disorder (SAD). We therefore explored the neural correspondences of these heart rate alterations. 21 patients with SAD and 21 matched healthy controls (HCs) underwent 3T-fMRI scanning. Simultaneously, high-frequency heart rate variability (HF-HRV) was acquired during a short-term resting period and an implicit emotional face-matching task. Compared to HCs, patients with SAD reported increased self-focused attention while being less accurate in estimating their heartbeats. Physiologically, they showed less HF-HRV at rest and during task. Across groups, HF-HRV at rest correlated positively with activation in visual face-processing areas. The right caudate nucleus showed an interaction of group and cardioregulation: Activation in this region was positively correlated in patients with SAD but negatively in HCs. We conclude that cardioregulation is altered in SAD on the subjective, physiological, and brain level.

Physiological stress responses predict sexual functioning and satisfaction differently in women who have and have not been sexually abused in childhood

Physiological responses to sexual stimuli may contribute to the increased rate of sexual problems seen in women with childhood sexual abuse (CSA) histories. We compared two physiological stress responses as predictors of sexual function and satisfaction, sympathetic nervous system (SNS) activation and cortisol in women with (CSA, N = 136) and without CSA histories (NSA, N = 102). In CSA survivors, cortisol response to sexual stimuli did not significantly predict sexual functioning; however, in NSA women, cortisol increases were associated with poorer sexual functioning, and decreases with higher functioning. For women with CSA histories, lower SNS activity was associated with poorer sexual functioning. For CSA survivors with low lifetime trauma, lower SNS activity was associated with higher sexual satisfaction; for women with high lifetime trauma, the reverse was true. Decreased SNS activity during sexual stimuli predicted higher sexual functioning in NSA women with low lifetime exposure to traumatic events, but lower sexual functioning in those with high exposure. Differences between women with and without CSA histories in the association between cortisol and SNS response and sexual functioning and satisfaction suggests that CSA causes disruptions in both short and long-term stress responses to sexual stimuli that perpetuate into adulthood.

Decreased cardiac vagal control in drug-naïve patients with posttraumatic stress disorder

OBJECTIVE

Decreased cardiac vagal control (CVC) has been proposed in posttraumatic stress disorder (PTSD), but the results are mixed. Analyses with larger sample sizes and better methodology are needed.

METHODS

Thirty-two drug-naïve survivors with current PTSD, 32 survivors without PTSD and 192 matched controls were recruited for a case-control analysis. We used the PTSD checklist-civilian version (PCL-C) to assess posttraumatic symptoms severity. Cardiac autonomic function was evaluated by measuring heart rate variability (HRV) parameters. Frequency-domain indices of HRV were obtained. The obtained results were evaluated in association with personality traits assessed by the Tridimensional Personality Questionnaire (TPQ).

RESULTS

PTSD patients exhibited decreased LF-HRV and HF-HRV as compared to survivors without PTSD and to matched controls. The PTSD symptoms severity was associated with reduced mean RR intervals, Var-HRV, LF-HRV and HF-HRV. The harm avoidance score (which has been suggested to be associated with serotonergic activity) was negatively correlated with Var-HRV, LF-HRV and HF-HRV.

CONCLUSION

These data suggest that PTSD is accompanied by decreased CVC, highlighting the importance of assessing HRV in PTSD patients. In view of the increased risk for cardiovascular diseases in these vulnerable individuals, one might consider the treatment to restore their autonomic function while reducing PTSD symptoms.

Diminished vagal activity and blunted diurnal variation of heart rate dynamics in posttraumatic stress disorder

Affected autonomic heart regulation is implicated in the pathophysiology of cardiovascular diseases and is associated with posttraumatic stress disorder (PTSD). However, although sympathetic hyperactivation has been repeatedly shown in PTSD, research has neglected parasympathetic function. The objective of this study is the long-term assessment of heart rate (HR) dynamics and its diurnal changes as an index of autonomic imbalance in PTSD. Since tonic parasympathetic activity underlies long-range correlation of heartbeat interval fluctuations in the healthy state, we included nonlinear (unifractal) analysis as an important and sensitive readout to assess functional alterations. We conducted electrocardiogram recordings over a 24-h period in 15 deployed male subjects with moderate to high levels of combat exposure (PTSD: n = 7; combat controls: n = 8) in the supine position. HR dynamics were assessed in two 5-h sub-epochs in the time and frequency domains, and by nonlinear analysis based on detrended fluctuation analysis. Psychiatric symptoms were assessed using structured interviews, including the Clinician Administered PTSD Scale. Subjects with PTSD showed significantly higher baseline HR, higher LF/HF ratio in the frequency domain, blunted differences between day and night-time measures, as well as a higher scaling coefficient αfast during the day, indicating diminished tonic parasympathetic activity. Diminished diurnal differences and blunted tonic parasympathetic activity altering HR dynamics suggest central neuroautonomic dysregulation that could represent a possible link to increased cardiovascular disease in PTSD.

Use of paced respiration to alleviate intractable hiccups (Singultus): a case report

Heart rate variability (HRV) biofeedback is an emerging treatment for many health conditions involving dysregulation of the autonomic nervous system including hypertension, gastric pain, anxiety, and depression. Hiccups are frequently considered an annoyance. However, when intractable (lasting over 1 month), they can become debilitating, with some patients resorting to invasive treatments that often involve the phrenic nerve. Theoretically, HRV biofeedback should also provide a means to stimulate the phrenic nerve and could be an alternative option. We report the successful treatment of a 5 year-long case of intractable hiccups with one session of HRV biofeedback training. These results suggest that biofeedback may be a useful, non-invasive means of relieving intractable hiccups. No clear causality can be inferred from a single case, and further study is needed to determine if this finding has wider applicability.

Preliminary findings of the relationship of lower heart rate variability with military sexual trauma and presumed posttraumatic stress disorder

Decreased heart rate variability (HRV) occurs with physical and psychological disorders and is a predictor of cardiac and all-cause mortality. This study was the first of which we are aware to examine and report the relationship between military sexual trauma (MST) and HRV measures. In a historical cohort study of female veterans with (n = 27) and without (n = 99) MST who received Holter and electrocardiogram evaluation at a Veteran Affairs medical center during 2007-2010, we examined the relationship between MST and the standard deviation of all R-R intervals (SDNN) and the square root of the mean of the sum of the squares of differences between adjacent R-R intervals (RMSSD). Female veterans with MST were younger, p = .002, frequently had a probable posttraumatic stress disorder diagnosis, 80% versus 15%, p = < .0001, and had lower SDNN, p = .0001, and RMSSD, p = .001, than those without MST. The SDNN and RMSSD of a 25-year-old female veteran with MST were comparable to that of female veterans aged 69 to 81 years without MST. Further research is needed to evaluate relationships between MST and HRV measures.

Breathing practices for treatment of psychiatric and stress-related medical conditions

Neurophysiological studies may explain how breathing techniques normalize stress response, emotion regulation, and autonomic and neuroendocrine system function. Breath practices have been shown to reduce symptoms of stress, anxiety, insomnia, post-traumatic stress disorder, mass disasters, depression, and attention deficit disorder. Technology-assisted breathing interventions facilitate therapeutic breathing by using either static cues such as a breath pacer or real-time feedback based on physiological parameters such as heart rate variability. The empirical literature indicates that technology-assisted breathing can be beneficial in mental health treatment, though it may not be appropriate for all individuals. Initial in-person training and evaluation can improve results.

Matter over mind: a randomised-controlled trial of single-session biofeedback training on performance anxiety and heart rate variability in musicians

BACKGROUND

Musical performance is a skilled activity performed under intense pressure, thus is often a profound source of anxiety. In other contexts, anxiety and its concomitant symptoms of sympathetic nervous system arousal have been successfully ameliorated with HRV biofeedback (HRV BF), a technique involving slow breathing which augments autonomic and emotional regulatory capacity.

OBJECTIVE

This randomised-controlled study explored the impact of a single 30-minute session of HRV BF on anxiety in response to a highly stressful music performance.

METHODS

A total of 46 trained musicians participated in this study and were randomly allocated to a slow breathing with or without biofeedback or no-treatment control group. A 3 Group×2 Time mixed experimental design was employed to compare the effect of group before and after intervention on performance anxiety (STAI-S) and frequency domain measures of HRV.

RESULTS

Slow breathing groups (n=30) showed significantly greater improvements in high frequency (HF) and LF/HF ratio measures of HRV relative to control (n=15) during 5 minute recordings of performance anticipation following the intervention (effect size: η(2) =0.122 and η(2) =0.116, respectively). The addition of biofeedback to a slow breathing protocol did not produce differential results. While intervention groups did not exhibit an overall reduction in self-reported anxiety, participants with high baseline anxiety who received the intervention (n=15) displayed greater reductions in self-reported state anxiety relative to those in the control condition (n=7) (r=0.379).

CONCLUSIONS

These findings indicate that a single session of slow breathing, regardless of biofeedback, is sufficient for controlling physiological arousal in anticipation of psychosocial stress associated with music performance and that slow breathing is particularly helpful for musicians with high levels of anxiety. Future research is needed to further examine the effects of HRV BF as a low-cost, non-pharmacological treatment for music performance anxiety.

Heart rate variability in the subsyndromal depressive phase of bipolar disorder

AIMS

To compare the heart rate variability of bipolar patients in the subsyndromal depressive phase with healthy controls and to evaluate the relationship between severity of subsyndromal depressive symptoms and heart rate variability.

METHODS

Thirty-three bipolar patients in the subsyndromal depressive phase and 59 healthy controls were enrolled. A patient was considered to be in a subsyndromal depressive phase when the Montgomery-Åsberg depression rating scale score was ≤10 and the Clinical Global Impression-Severity scale (CGI-S) was ≤3 for the previous 1 month. After approximately 10 min of supine rest, all participants underwent resting electrocardiograms for 5 min in the supine position using limb leads. Different parameters of heart rate variability were analyzed in the time and frequency domains.

RESULTS

Bipolar patients had significantly lower standard deviation of all RR intervals (SDNN), proportion of adjacent NN intervals that differ by >50 ms (pNN50), log total power (log TP) and very low frequency power (VLF) compared to healthy controls. There were significant negative correlations between CGI-S score and some heart rate variability parameters, including heart rate variability index, SDNN, root mean square successive difference (RMSSD), pNN50, log TP, VLF, low frequency power (LF) and high frequency power (HF).

CONCLUSION

Patients with bipolar disorder in the subsyndromal depressive state have reduced heart rate variability relative to healthy controls, and reduction of heart rate variability appears to be correlated with severity of symptoms in bipolar patients.

Post-traumatic stress disorder and migraine: epidemiology, sex differences, and potential mechanisms

Migraine is a common, often disabling disorder associated with a significant personal and societal burden. The presence of post-traumatic stress disorder (PTSD) may increase this disability substantially. Migraine and PTSD are both up to 3 times more common in women than in men. The divergence in prevalence rates of migraine and PTSD that occurs between the sexes after puberty suggests that gonadal hormones play an important role. In addition, the preponderance of PTSD in women may be related to their higher rates of interpersonal trauma, the most common cause of PTSD. However, recent data suggest that although the odds of PTSD are increased in both women and men with episodic migraine, this association is stronger in men than women. In this paper, we examine the epidemiology of PTSD and migraine, with an emphasis on the known sex differences. We then discuss the neurobiological changes associated with PTSD, the current hypotheses for the mechanisms relating PTSD and migraine, and the treatment implications of these findings.