Are affective disorders associated with alterations of heart rate variability?

Link between Yoga and Heart Rate Variability: Can Yoga Enhance the Cardiac Resonance

Cardiac resonance is a complicated phenomenon involving the coordinated oscillations of numerous circulatory system components, such as electrical activity, contraction and relaxation, and blood flow. It is critical for the normal functioning of the heart and for maintaining blood flow throughout the body. Cardiac resonance is defined as a series of tiny waves produced by the heartbeat and overlaid on flow data and airway pressures. A variety of technologies, including cardiac magnetic resonance (CMR) imaging, can be used to identify these waves. CMR is a strong noninvasive method for seeing and quantifying heart anatomy and function in great detail. CMR can be used to assess cardiac resonance in both healthy and heart disease patients. A regular and coordinated pattern of oscillations characterizes cardiac resonance in healthy persons. In patients with heart illness, however, cardiac resonance can be interrupted, resulting in diminished cardiac function and decreased blood flow. The intricate role of cardiac resonance in cardiac health and disease is continuously being studied by researchers. However, it is obvious that cardiac resonance is an exciting area of research that has the potential to change the way to identify and treat heart illness. Yoga is a mind-body practice that has been demonstrated to have numerous cardiovascular health advantages, such as improved heart function, reduced inflammation, and lower blood pressure. Yoga is hypothesized to promote cardiac resonance by encouraging coordinated oscillations of numerous cardiovascular system components. Various researches have shown buoyant results such as yoga can be helpful in improving heart rate variability, cardiac resonance and reducing arterial stiffness. Stress can disrupt cardiac resonance and increase the risk of heart disease. More research is needed to completely understand the mechanisms that impact cardiac resonance and the long-term advantages of yoga for heart health.

Heart Rate Variability: A Measure of Cardiovascular Health and Possible Therapeutic Target in Dysautonomic Mental and Neurological Disorders

Mental illness such as depression and anxiety as well as cerebrovascular disease are linked to impairment of neurocardiac function mediated by changes to the autonomic nervous system with increased sympathetic and decreased parasympathetic activity. Autonomic neurocardiac function can be evaluated by computing heart rate variability (HRV). Over the past decades, research has demonstrated the diagnostic value of HRV as independent predictor of cardiovascular mortality and as disease marker in progressive autonomic nervous system disorders such as Parkinson’s disease. Here we summarize our studies on HRV and its therapeutic modulation in the context of psychopharmacology as well as psychiatric and neurological disorders to honor the life of Professor Evgeny Vaschillo, the true pioneer of HRV research who sadly passed away on November 21st, 2020.

Effects of Missing Data on Heart Rate Variability Metrics

Heart rate variability (HRV) has been studied for decades in clinical environments. Currently, the exponential growth of wearable devices in health monitoring is leading to new challenges that need to be solved. These devices have relatively poor signal quality and are affected by numerous motion artifacts, with data loss being the main stumbling block for their use in HRV analysis. In the present paper, it is shown how data loss affects HRV metrics in the time domain and frequency domain and Poincaré plots. A gap-filling method is proposed and compared to other existing approaches to alleviate these effects, both with simulated (16 subjects) and real (20 subjects) missing data. Two different data loss scenarios have been simulated: (i) scattered missing beats, related to a low signal to noise ratio; and (ii) bursts of missing beats, with the most common due to motion artifacts. In addition, a real database of photoplethysmography-derived pulse detection series provided by Apple Watch during a protocol including relax and stress stages is analyzed. The best correction method and maximum acceptable missing beats are given. Results suggest that correction without gap filling is the best option for the standard deviation of the normal-to-normal intervals (SDNN), root mean square of successive differences (RMSSD) and Poincaré plot metrics in datasets with bursts of missing beats predominance (p<0.05), whereas they benefit from gap-filling approaches in the case of scattered missing beats (p<0.05). Gap-filling approaches are also the best for frequency-domain metrics (p<0.05). The findings of this work are useful for the design of robust HRV applications depending on missing data tolerance and the desired HRV metrics.

The Effect of Music on Preoperative Anxiety in an Operating Room: a Single-Blind Randomized Controlled Trial

OBJECTIVE

This study aimed to determine the effect of music as an intervention on relieving preoperative anxiety in patients with dental fear in an outpatient operating room (OR) before intravenous sedation (IVS).

METHODS

Sixty adult patients with dental fear undergoing dental surgery under IVS were divided into 2 groups (music and nonmusic). The music group listened to music in the waiting room until immediately before the initiation of IVS whereas the nonmusic group did not. Patient anxiety was objectively measured using heart rate variability (HRV) analysis to assess the low-frequency/high-frequency ratio as an indication of sympathetic or parasympathetic nervous system activity. Subjective preoperative anxiety was evaluated with a visual analog scale (VAS).

RESULTS

Heart rate variability analysis failed to demonstrate any significant difference between the 2 groups from baseline to start of IVS. There were also no significant differences between the 2 groups regarding changes in VAS scores.

CONCLUSION

Music intervention was not found to reduce preoperative anxiety in patients with dental fear before IVS in the dental outpatient OR as determined by HRV analysis or VAS scores.

The psychophysiological correlates of cognitive dissonance

This preregistered study uses a combination of physiological measures to explore both the activation and reduction components of cognitive dissonance theory. More precisely, we use skin conductance to identify dissonance arousal, a short-term affective response to counter-attitudinal stimuli, and then use heart rate variability to measure dissonance reduction, which reflects longer-term patterns of emotional regulation and information processing. Our preliminary tests find weak evidence of dissonance arousal and no evidence of dissonance reduction using this physiological approach. We consequently reconsider (albeit optimistically) the use of physiology in future work on cognitive dissonance. We also discuss the implications of our findings for selective exposure and motivated reasoning.

Children with developmental dyslexia show elevated parasympathetic nervous system activity at rest and greater cardiac deceleration during an empathy task

Reading difficulties are the hallmark feature of dyslexia, but less is known about other areas of functioning. Previously, we found children with dyslexia exhibited heightened emotional reactivity, which correlated with better social skills. Whether emotional differences in dyslexia extend to the parasympathetic nervous system-an autonomic branch critical for attention, social engagement, and empathy-is unknown. Here, we measured autonomic nervous system activity in 24 children with dyslexia and 24 children without dyslexia, aged 7 - 12, at rest and during a film-based empathy task. At rest, children with dyslexia had higher respiratory sinus arrhythmia (RSA) than those without dyslexia. Cardiac deceleration during the empathy task was greater in dyslexia and correlated with higher resting RSA across the sample. Children with dyslexia produced more facial expressions of concentration during film-viewing, suggesting greater engagement. These results suggest elevated resting parasympathetic activity and accentuated autonomic and behavioral responding to others' emotions in dyslexia.

Interactive effects of childhood maltreatment and tonic respiratory sinus arrhythmia on young adults' depressive symptoms

The goal of the current study was to investigate the moderating effect of tonic respiratory sinus arrhythmia (RSA) in the relation between childhood maltreatment and depression symptoms among young adults. A total of 98 participants (70 women) aged 17-22 years completed questionnaires on childhood maltreatment and depressive symptoms. RSA data were obtained during a resting condition in the laboratory. Results indicated that childhood maltreatment interacted with tonic RSA to predict depressive symptoms, even after controlling for age and body mass index (BMI) of each participant. Specifically, higher levels of childhood maltreatment were associated with higher levels of depressive symptoms, but only among young adults who exhibited lower tonic RSA. The results indicated that the association between childhood maltreatment and depressive symptoms depends on young adults' physiological functioning/flexibility. Findings suggest that consideration of external environmental factors in combination with internal physiological factors is critical to understand young adults' mental health.

An Integrative Model for the Effectiveness of Biofeedback Interventions for Anxiety Regulation: Viewpoint

Biofeedback has shown to be a promising tool for the treatment of anxiety; however, several theoretical as well as practical limitations have prevented widespread adaptation until now. With current technological advances and the increasing interest in the use of self-monitoring technology to improve mental health, we argue that this is an ideal time to launch a new wave of biofeedback training. In this viewpoint paper, we reflect on the current state of biofeedback training, including the more traditional techniques and mechanisms that have been thought to explain the effectiveness of biofeedback such as the integration of operant learning and meditation techniques, and the changes in interoceptive awareness and physiology. Subsequently, we propose an integrative model that includes a set of cognitive appraisals as potential determinants of adaptive trajectories within biofeedback training such as growth mindset, self-efficacy, locus of control, and threat-challenge appraisals. Finally, we present a set of detailed guidelines based on the integration of our model with the mechanics and mechanisms offered by emerging interactive technology to encourage a new phase of research and implementation using biofeedback. There is a great deal of promise for future biofeedback interventions that harness the power of wearables and video games, and that adopt a user-centered approach to help people regulate their anxiety in a way that feels engaging, personal, and meaningful.

Cardiovascular reactivity to acute stress associated with sickness absence among Japanese men and women: A prospective study

OBJECTIVE

We aimed to investigate associations between cardiovascular reactivity to acute stress and sickness absence among Japanese male and female workers, in a prospective study.

METHODS

Among healthy employed Japanese workers who underwent mental health checks between 2006 and 2009, data of 111 participants were analyzed. Changes in blood pressure, pulse rate, peripheral blood flow (PBF), and heart rate variability (HRV) (high frequency [HF] and low frequency [LF]) were calculated using differences between the two tasks, mirror drawing stress [MDS] and a maze task, and the postperiod value. Sickness absence through March 2010 was followed up by mail survey (average follow-up 2.3 years). Logistic regression analysis was used, adjusting for lifestyle factors.

RESULTS

Among 12 participants who took sickness absences, eight were owing to mental problems. Changes in the LF during the MDS and maze tasks and LF-to-HF ratio during the MDS task were positively associated with all sickness absences (odds ratio [OR], 95% confidence interval [CI]: 2.09, 1.03-4.22; 2.04, 1.09-3.82; and 3.10, 1.46-6.58, respectively). Changes in PBF during the MDS task were also associated with increased risk of sickness absence (OR, 95% CI: 2.53, 1.10-5.81).

CONCLUSION

Cardiovascular reactivity to acute stress should be considered at workers' health checks.

Spectral Analysis of Heart Rate Variability: Time Window Matters

Spectral analysis of heart rate variability (HRV) is a valuable tool for the assessment of cardiovascular autonomic function. Fast Fourier transform and autoregressive based spectral analysis are two most commonly used approaches for HRV analysis, while new techniques such as trigonometric regressive spectral (TRS) and wavelet transform have been developed. Short-term (on ECG of several minutes) and long-term (typically on ECG of 1–24 h) HRV analyses have different advantages and disadvantages. This article reviews the characteristics of spectral HRV studies using different lengths of time windows. Short-term HRV analysis is a convenient method for the estimation of autonomic status, and can track dynamic changes of cardiac autonomic function within minutes. Long-term HRV analysis is a stable tool for assessing autonomic function, describe the autonomic function change over hours or even longer time spans, and can reliably predict prognosis. The choice of appropriate time window is essential for research of autonomic function using spectral HRV analysis.

The moderating effect of heart rate variability on the relationship between alpha asymmetry and depressive symptoms

Electroencephalographic (EEG) research has suggested relatively reduced brain activity in the left frontal and right posterior region trait-markers of depression. However, inconsistent results have been reported. Based on previous studies reporting the heart rate variability (HRV) as an index of emotional regulation, this study makes a novel investigation of the role of heart rate variability (HRV) as a moderator in the relationship between frontal and parietal alpha asymmetry and depression. Resting EEG (eyes open) was recorded in 38 patients with MDD and 34 healthy subjects. Frontal and parietal alpha asymmetries were calculated at total (8–12 Hz), high (10–12 Hz), and low (8–10 Hz) alpha frequency bands. Three vagally mediated HRV (vmHRV) components (LF, HF, and the LF/HF ratio) were calculated in the frequency domain. Relatively greater right parietal alpha activity significantly predicted the severity of depression only when HF was low (or the LF/HF ratio was high) at low alpha frequency band. The interaction effect of parietal alpha asymmetry and vmHRV remained significant after including anxiety score as a covariate. No moderation effect of vmHRV was found for frontal sites and other frequency bands, as well as healthy subjects. These findings suggest that vmHRV moderates the association between parietal alpha asymmetry at low frequency band and depression for MDD patients. We suggest that the interaction between parietal alpha asymmetry and vmHRV may be a biomarker of MDD.

Reduced heart rate variability in a treatment-seeking early psychosis sample

Reduced cardiac autonomic function is associated with increased risk of cardiovascular disease (CVD), with heart rate variability (HRV) providing an accessible index of cardiac autonomic function. HRV may provide a candidate physiological mechanism linking reduced cardiac autonomic function to increased risk for CVD in schizophrenia illness. This study examines whether HRV is also reduced in a community sample of treatment-seeking participants experiencing early psychosis (n = 48) compared to healthy volunteers (n = 48) and social anxiety control groups (n = 48) matched by gender and age. HRV was assessed during a five-minute interbeat interval recording at rest. Participants also completed self-report psychiatric symptom measures. Early psychosis participants showed significant reductions in HRV compared to social anxiety and healthy control groups. Reductions in HRV were also observed in early psychosis participants taking anticholinergic medications compared to both control groups taking cardio-benign medications or who were non-medicated. Lastly, whether or not early psychosis participants were taking anticholinergic medications was not associated with reductions in HRV. Findings provide preliminary evidence that early psychosis is associated with reduced HRV. This study supports further research with larger sample sizes to precisely determine the influence of anticholinergic drugs on HRV in early psychosis populations.

Cardiac and behavioral effects of social isolation and experimental manipulation of autonomic balance

Improved understanding of how depression and social isolation interact to increase cardiac morbidity and mortality will improve public health. This experiment evaluated the effect of pharmacological autonomic blockade on cardiac and behavioral reactivity following social isolation in prairie voles. Experiment 1 validated the dose and time course of pharmacological autonomic antagonism of peripheral β-adrenergic (atenolol) and muscarinic cholinergic receptors (atropine methyl nitrate), and Experiment 2 used a novel protocol to investigate behavioral responses in the tail suspension test during pharmacological autonomic blockade as a function of social isolation (vs. paired control). Prairie voles isolated for 4 weeks (vs. paired) displayed significantly elevated heart rate and reduced heart rate variability. Autonomic receptor antagonism by atenolol led to exaggerated reductions in heart rate and standard deviation of normal-to-normal intervals, and lower amplitude of respiratory sinus arrhythmia in the isolated group (vs. paired). Administration of atropine led to an attenuated increase in heart rate in the isolated group (vs. paired), and similar near-zero levels of respiratory sinus arrhythmia amplitude in both groups. During the tail suspension test, isolated animals (vs. paired) displayed significantly greater immobility. In paired animals, atenolol administration did not influence immobility; atropine administration increased the duration of immobility (vs. vehicle). In isolated animals, atenolol administration increased the duration of immobility; atropine did not influence immobility duration (vs. vehicle). The current study contributes to our understanding of differential effects of social isolation and autonomic imbalance on cardiac and behavioral reactivity.

Psychopathology, everyday behaviors, and autonomic activity in daily life: An ambulatory impedance cardiography study of depression, anxiety, and hypomanic traits

Discrepancies regarding the link between autonomic nervous system (ANS) activity and psychopathology may be due in part to inconsistent measurement of non-psychological factors, including eating, drinking, activity, posture, and interacting with others. Rather than sources of noise, behaviors like being active and being with others may be the behavioral pathways that connect psychopathology symptoms to autonomic activity. The present study examined whether behaviors mediate the association of depression, anxiety, and hypomanic traits with ANS by using experience sampling methodology and ambulatory impedance cardiography. Participants (n = 49) completed measures of affect and one day of experience sampling and ambulatory impedance cardiography. The association of hypomanic traits with heart rate variability and heart rate was mediated by physical activity, and social activity mediated the association of depressive symptoms and respiration. These results highlight the importance of considering the pathways between psychopathology and ANS and the mediating role that everyday behaviors play.

Heartbeat Complexity Modulation in Bipolar Disorder during Daytime and Nighttime

This study reports on the complexity modulation of heartbeat dynamics in patients affected by bipolar disorder. In particular, a multiscale entropy analysis was applied to the R-R interval series, that were derived from electrocardiographic (ECG) signals for a group of nineteen subjects comprised of eight patients and eleven healthy control subjects. They were monitored using a textile-based sensorized t-shirt during the day and overnight for a total of 47 diurnal and 27 nocturnal recordings. Patients showed three different mood states: depression, hypomania and euthymia. Results show a clear loss of complexity during depressive and hypomanic states as compared to euthymic and healthy control states. In addition, we observed that a more significant complexity modulation among healthy and pathological mood states occurs during the night. These findings suggest that bipolar disorder is associated with an enhanced sleep-related dysregulation of the Autonomic Nervous System (ANS) activity, and that heartbeat complex dynamics may serve as a viable marker of pathological conditions in mental health.

Depression recognition according to heart rate variability using Bayesian Networks

BACKGROUND

Doctors mainly use scale tests and subjective judgment in the clinical diagnosis of depression. Researches have demonstrated that depression is associated with the dysfunction of the autonomic nervous system (ANS), where its modulation can be evaluated by heart rate variability (HRV). Depression patients have lower HRV than healthy subjects. Therefore, HRV may be used to distinguish depression patients from healthy people.

METHODS

HRV signals were collected from 76 female subjects composed of 38 depression patients and 38 healthy people. Time domain, frequency domain, and non-linear features were extracted from the HRV signals of these subjects, who were subjected to the Ewing test as an ANS stimulus. Then, these multiple features were input into Bayesian networks, served as a classifier, to distinguish depression patients from healthy people. Hence, accuracy, sensitivity, and specificity were calculated to evaluate the performance of the classifier.

RESULTS

Recognition results indicate 86.4% accuracy, 89.5% sensitivity, and 84.2% specificity. The individuals subjected to the Ewing test showed better recognition results than those at individual test states (resting state, deep breathing state, Valsalva state, and standing state) of the Ewing test. The root mean square of successive differences (RMSSD) of the HRV exhibits a significant relevance with recognition.

CONCLUSION

Bayesian networks can be applied to the recognition of depression patients from healthy people and the recognition results demonstrate the significant association between depression and HRV. The Ewing test is a good ANS stimulus for acquiring the difference of HRV between depression patients and healthy people to recognize depression. The RMSSD of the HRV is important in recognition and may be a significant index in distinguishing depression patients from healthy people.

Differences of sympathetic and parasympathetic modulation in major depression

Inconsistent results have been reported with respect to cardiac autonomic function in major depression. The aim of our study was to investigate autonomic function in various branches of the autonomic nervous system in order to better understand parasympathetic and sympathetic modulation in the disease. We investigated 29 unmedicated patients suffering from major depression (MD) in comparison to matched control subjects (gender, age, BMI). The autonomic assessment at rest included values of heart rate variability (HRV), blood pressure variability (BPV), baroreflex sensitivity (BRS), respiration, skin conductance (SC) as well as the calculation of pupillary diameter and the unrest index (PUI). Results were compared by means of a multivariate analysis of variance. In a classification analysis, we identified suitable parameters for patient - control separation. Finally, to analyze interrelations of pupillometric parameters and autonomic indices, we estimated Pearson correlation coefficients and fitted a linear regression model. Apart from a significantly increased heart rate (75±12 vs. 65±6min^-1, p<0.001) and decreased BRS (14±13 vs. 20±15ms/mmHg, p<0.05), we observed a lack of significant differences in HRV and BPV analysis between patients and controls. However, pupillary diameter (left: 4.3±0.9 vs. 3.8±0.6, p<0.01; right: 4.3±0.9 vs. 3.7±0.6mm, p<0.01) and PUI (left: 14.8±6.0 vs. 10.7±4.5mm/min, p<0.01; right: 14.1±5.5 vs. 10.7±4.8mm/min, p<0.01), as well as the level (left: 7.3±6.2 vs. 4.3±4.4 μS, p<0.05) and fluctuations of skin conductance (left: 4.2±4.1 vs. 2.5±3.6, p<0.05; right: 4.2±4.4 vs. 2.6±3.2, p<0.05) were significantly different. The classification accuracy was 88.5% with high specificity (e=92.9%) and sensitivity (s=83.3%) including heart rate, PUI and skin conductance. HRV indices correlated to PUI in controls but not in patients. Our data add evidence to the current debate on autonomic function in major depression. We suggest that diverse results are mainly caused by methodological shortcomings, in particular by the application of HRV assessment only, which misses changes of sympathetic modulation. The application of broader analyzing tools will clarify the pattern of autonomic function in depression and ultimately its role in cardiac morbidity and mortality.

Alcohol Use Disorder Moderates the Effect of Age on Heart Rate Variability in Veterans With Posttraumatic Stress Disorder

Research on heart rate variability (HRV) in posttraumatic stress disorder (PTSD) and comorbid alcohol use disorder (AUD) is limited despite its use as a biomarker of both disorders. This study examined whether AUD comorbidity contributes an additive effect on HRV for veterans with PTSD. HRV was assessed in 70 male Operation Enduring Freedom/Operation Iraqi Freedom veterans with PTSD, including 32 with co-occurring AUD. Mean HRV values for both groups were below the mean for healthy adults, but additive effects of PTSD and AUD on HRV were not observed. Consistent with prior studies, hierarchical regressions showed that HRV decreased with age in the PTSD-only group. However, HRV increased slightly with age among veterans with both PTSD and AUD. This interaction remained significant after controlling for common HRV covariates. These findings support HRV as a biomarker of PTSD and extend research by demonstrating the complex relationship between PTSD and HRV in the context of co-occurring AUD.

Prevalence of late potentials on signal-averaged ECG in patients with psychiatric disorders

BACKGROUND

Sudden cardiac death (SCD) occurs three times more often in psychiatric patients than in the general population. QRS fragmentation (QRSfr) and signal-averaged electrocardiography (SAECG) are simple, inexpensive, readily available tools for detecting the presence of abnormal depolarization and late potentials (LPs) in these patients, a result of either the underlying disease or treatment.

METHODS

Frequency of LP detection by SAECG and QRSfr was studied in 52 psychiatric patients and compared with 30 healthy (without known structural heart disease or occurrence of ventricular arrhythmia) controls. Patients were then prospectively followed up and incidence of SCD was recorded.

RESULTS

LP prevalence was significantly higher in patients than in controls (16/52-31% vs 2/30-7%, p=0.012), while QRSfr was similar between these two groups (p=0.09). Of the LP presence criteria, the root mean square value at terminal 40msec of the QRS (RMS40) was significantly lower in patients (32μV, SD=19μV, vs 46μV, SD=32μV, p=0.015). Among patients, no differences were noted between the LP positive and negative groups regarding age, sex, number of medications, class of antipsychotics and defined daily doses. Mean follow-up was 46months (SD=11) and during it 3 patients suffered SCD. Although 2 SCD victims had both LPs and QRSfr concurrently present, neither of them, nor their simultaneous presence could definitely account for the events.

CONCLUSIONS

LP prevalence in psychiatric patients was significantly higher than in controls. SAECG performance was feasible in all cases and constitutes a readily available tool for assessing myocardial electrophysiological alterations in this patient group.

Music before Dental Surgery Suppresses Sympathetic Activity Derived from Preoperative Anxiety: A Randomized Controlled Trial

The aim of this study was to estimate the relieving effect of music intervention on preoperative anxiety by using heart rate variability (HRV) analysis. In this randomized controlled trial, 86 adult patients were scheduled to undergo impacted tooth extraction under intravenous sedation and local anesthesia and were classified as either fearful or nonfearful based on a questionnaire. Thereafter, the patients were subdivided into 2 groups: those who listened to music from the time that they arrived at the outpatient clinic until immediately before entering the operating room and those who did not listen to music. The effect of music intervention was evaluated by assessing 1) the low-frequency/high-frequency ratio of HRV, in which positive changes indicate increased sympathetic nervous activity, and 2) the coefficient of component variance for high frequency, in which positive changes indicate increased parasympathetic nervous activity, assessed by means of HRV analysis. Subjective preoperative anxiety was evaluated on a visual analog scale. For fearful patients, the mean magnitude of low-frequency/high frequency changes from baseline among those who listened to music was significantly lower as compared with those who did not listen to music (in the private room: -1.45 ± 1.88 vs. 1.05 ± 1.88, P = 0.0096, 95% confidence interval of effect size = -4.52 to -0.48, Cohen's d = -0.75; in the operating waiting room: -2.18 ± 2.39 vs. -0.10 ± 3.37, P = 0.011, 95% confidence interval of effect size = -3.94 to -0.22, Cohen's d = -0.71, respectively). Visual analog scale scores were also significantly different. Coefficient of component variance for high frequency and heart rate did not differ significantly between the 2 groups. From the perspective of autonomic nervous activity, music intervention is useful for relieving anxiety in patients with dental fear before they enter a dental outpatient operating room. Music intervention may relieve anxiety by reducing sympathetic nervous activity, while parasympathetic nervous activity is not involved (UMIN000016882). Knowledge Transfer Statement: The results of this study revealed that music intervention is useful for clinicians when planning preoperative anxiety management of patients with dental fear who undergo impacted tooth extraction under intravenous sedation and local anesthesia. As a bridging intervention, music intervention enables stress management to continue uninterrupted from the patient's arrival at the dental outpatient clinic to intravenous sedation until completion of the dental surgery. With consideration of cost-effectiveness, absence of adverse physical effects, immediate effect, safety in terms of not using drugs, and lack of concerns about recovery, this information could lead to more appropriate decisions regarding anxiety management in dentistry.

The Role of Brain Structure and Function in the Association Between Inflammation and Depressive Symptoms: A Systematic Review

OBJECTIVE

Major depressive disorder and related symptoms have been shown to be associated with inflammation, and this association is likely to be mediated through changes in brain structure and function. This article provides a systematic review of studies that have used brain imaging techniques to identify neural mechanisms linking inflammation and depressive symptoms.

METHODS

A systematic search of online databases identified 26 studies that fulfilled the inclusion and exclusion criteria.

RESULTS

In general, increased peripheral inflammation was associated with differences in function in several subcortical regions, as well as medial and ventral prefrontal regions-both at rest (7 studies) and during exposure to emotional stimuli (14 studies). Also, increased activation in some of these regions was associated with depression (18 studies). Too few studies have measured neuroinflammation markers (three) or brain structure (three), so generalizations about these mechanisms cannot yet be made.

CONCLUSIONS

This review supports the view that peripheral inflammation is an etiological process that may influence depression via effects on brain function. Several methodological inconsistencies in the extant literature need to be addressed, most notably a lack of formal mediational testing in longitudinal designs and inconsistencies across imaging methods and inflammation induction and measurement techniques. Further work is also required to establish the mechanisms by which basal inflammation levels influence brain function and depressive symptoms in both healthy and clinical samples.

Positive Psychotherapy to Improve Autonomic Function and Mood in ICD Patients (PAM-ICD): Rationale and Design of an RCT Currently Underway

BACKGROUND

Improving mental and physical health of patients with implantable cardioverter defibrillators (ICD) is critical because this group is at high risk for ventricular arrhythmias and sudden death and depressed or anxious cardiovascular disease (CVD) patients appear to be at even higher risk for mortality compared to nondepressed or nonanxious CVD patients. Further, autonomic dysfunction is present in these patients, and negative emotions and arrhythmias form a downward spiral further worsening mood, well-being, and cardiovascular health. Much research demonstrates that positive emotion is related to health benefits, improved physiology, and increased survival.

METHODS AND RESULTS

This is a two-arm randomized controlled trial aiming to recruit 60 adult ICD patients comparing 12 individually delivered, weekly sessions of: (1) a positive emotion-focused cognitive-behavioral therapy (Quality of Life Therapy [QOLT]), and (2) Heart Healthy Education. Autonomic functioning, heart rhythm indices, and psychosocial health are measured at baseline, 3 months, and 9 months. The first goal is feasibility and acceptability, with the primary outcome being arrhythmic event frequency data.

CONCLUSION

This study is designed to test whether QOLT produces changes in mood, quality of life/well-being, autonomic function, and arrhythmic and ICD therapy event rates. This feasibility trial is a foundational step for the next trial of QOLT to help determine whether a 3-month QOLT trial can reduce arrhythmias occurrences among ICD patients, and examine a mechanism of autonomic functioning. This study may help to develop and implement new medical or psychological therapies for ICD patients.

Role of peripheral vascular resistance for the association between major depression and cardiovascular disease

Major depression and cardiovascular diseases are 2 of the most prevalent health problems in Western society, and an association between them is generally accepted. Although the specific mechanism behind this comorbidity remains to be elucidated, it is clear that it has a complex multifactorial character including a number of neuronal, humoral, immune, and circulatory pathways. Depression-associated cardiovascular abnormalities associate with cardiac dysfunctions and with changes in peripheral resistance. Although cardiac dysfunction in association with depression has been studied in detail, little attention was given to structural and functional changes in resistance arteries responsible for blood pressure control and tissue perfusion. This review discusses recent achievements in studies of depression-associated abnormalities in resistance arteries in humans and animal experimental models. The changes in arterial structure, contractile and relaxing functions associated with depression symptoms are discussed, and the role of these abnormalities for the pathology of major depression and cardiovascular diseases are suggested.

Stress of Kindergarten teachers: How we tried to detect and to reduce it by using a small and wearable ECG and acceleration measuring device?

In 2014 school year, four female teachers of Nazareth Kindergarten decided to resign (DRT) due to workplace stress caused by human relationships between themselves. Our preliminary interview investigation revealed there was a stressor (STR), a certain elder female teacher and her less polite words and attitude. Using small and wearable ECG and acceleration measuring device, we measured 24 hour's autonomic nervous system's activity (ASNA) and sleep behavior of the STR and surrounding teachers, and tried to evaluate their stress objectively and to understand the reason of STR's less polite behaviors. For comparison, we also measured female Mind-Body Medicine (MBM) patients suffering adjustment disorder and clinical depression.

The variable heart: High frequency and very low frequency correlates of depressive symptoms in children and adolescents

BACKGROUND

Work examining the link between lower heart rate variability (HRV) and depression in children and adolescents is lacking, especially in light of the physiological changes that occur during pubertal development.

METHOD

We investigated the association between spectral measures of resting HRV and depressive symptoms among 127 children and adolescents, ages 10-17. Using spectral analysis, we evaluated (1) the association between relative high frequency (HF) HRV and depressive symptoms; (2) the predictive power of relative HF HRV for depressive symptoms in the context of relative low frequency (LF) and relative very low frequency (VLF) HRV; and (3) the relationship between relative HF, LF, and VLF band activity, age and pubertal maturation.

RESULTS

Consistent with previous work, results revealed that relative HF HRV was negatively associated with self-reported depressive symptoms. As well, relative VLF HRV was positively associated with depressive symptoms. Regression analyses revealed that relative HF HRV and relative VLF HRV significantly predicted self-report depressive symptoms while controlling for age, sex and pubertal maturation, with relative VLF HRV emerging as the strongest indicator of depressive symptoms. Developmental findings also emerged. Age and pubertal maturation were negatively associated with relative HF HRV and positively correlated with relative VLF HRV.

CONCLUSIONS

Results provide support for the relationship between HRV and depression and suggest that both HF and VLF HRV are relevant to depression symptom severity. Findings also reinforce the importance of considering pubertal development when investigating HRV-depression associations in children and adolescents.

LIMITATIONS

Influences on cardiac control including physical activity levels and exercise patterns could be controlled in future work. Our data speak to a depressive symptom dimension and relative spectral power HRV. Thus, we cannot make strong claims about relative spectral power HRV and clinical depression.

Examining biological vulnerability in environmental context: Parenting moderates effects of low resting respiratory sinus arrhythmia on adolescent depressive symptoms

Polyvagal theory suggests that parasympathetic regulation of cardiac function, indexed by resting respiratory sinus arrhythmia (RSA), may be a marker of emotion regulatory capacity and associated with youth psychopathology. Contemporary models of psychopathology suggest that the effects of biological vulnerability may be moderated by developmental context. The aim of the present study was to examine whether parenting, particularly parental responses to youth's negative emotions, moderated the effects of resting RSA on depressive symptoms among early adolescents. We examined resting RSA, depressive symptoms, and parental responses to youth negative emotions among 120 adolescents aged 11-14 years (M = 12.86, SD = .85; 52.5% female). Resting RSA and lack of supportive parenting interacted to predict youth depressive symptoms, such that low resting RSA predicted more depressive symptoms only in the context of low levels of supportive parental responses to youth's negative emotions. By contrast, high resting RSA buffered the effects of low supportive parenting on youth depressive symptoms. These findings highlight the importance of understanding joint contributions of biological vulnerability and developmental context on youth depression outcomes.

Heart rate variability as a potential indicator of positive valence system disturbance: A proof of concept investigation

One promising avenue toward a better understanding of the pathophysiology of positive emotional disturbances is to examine high-frequency heart rate variability (HRV-HF), which has been implicated as a potential physiological index of disturbances in positive emotional functioning. To date, only a few psychopathology relevant studies have systematically quantified HRV-HF profiles using more ecologically valid methods in everyday life. Using an experience-sampling approach, the present study examined both mean levels and intra-individual variability of HRV-HF - as well as comparison measures of cardiovascular arousal, sympathetic activity, and gross somatic movement - in everyday life, using ambulatory psychophysiological measurement across a six-day consecutive period among a spectrum of community adult participants with varying degrees of positive valence system disturbance, including adults with bipolar I disorder (BD; n=21), major depressive disorder (MDD; n=17), and healthy non-psychiatric controls (CTL; n=28). Groups did not differ in mean HRV-HF, but greater HRV-HF instability (i.e., intra-individual variation in HRV-HF) was found in the BD compared to both MDD and CTL groups. Subsequent analyses suggested that group differences in HRV-HF variability were largely accounted for by variations in clinician-rated manic symptoms. However, no association was found between HRV-HF variability and dimensional measures of positive affectivity. This work provides evidence consistent with a quadratic relationship between HRV-HF and positive emotional disturbance and represents a valuable step toward developing a more ecologically valid model of positive valence system disturbances and their underlying psychophysiological mechanisms within an RDoC framework.

The Association between Neuroticism and Heart Rate Variability Is Not Fully Explained by Cardiovascular Disease and Depression

Neuroticism is associated with cardiovascular disease, autonomic reactivity, and depression. Here we address the extent to which neuroticism accounts for the excess heart disease risk associated with depression and test whether cardiac autonomic tone plays a role as mediator. Subjects were derived from a nationally representative sample (n = 1,255: mean age 54.5, SD = 11.5). Higher neuroticism was associated with reduced heart rate variability equally under rest and stress. The baseline structural equation model revealed significant paths from neuroticism to heart rate variability, cardiovascular disease and depression, and between depression and cardiovascular disease, controlling for age, sex, height, weight, and BMI. Dropping both the neuroticism to heart rate variability, and neuroticism to heart disease paths significantly reduced the model fit (p < .001 in each case). We conclude that neuroticism has independent associations with both autonomic reactivity and cardiovascular disease, over and above its associations with depression and other related variables.

Somatic, but not cognitive-affective, symptoms are associated with reduced heart rate variability in individuals with dysphoria

Background: Somatic, but not cognitive–affective, symptoms of depression have been associated with reduced heart rate variability (HRV), and with poor prognosis in cardiovascular patients. However, factors concomitant with cardiovascular diseases may confound the relationship between somatic symptoms of depression and reduced HRV. Therefore, this study examined whether reduced HRV was differentially associated with cognitive–affective and somatic symptoms of depression in medically healthy individuals with and without dysphoria.

Methods: Self-reported cognitive–affective and somatic symptoms as measured with the Beck Depression Inventory-II questionnaire and time and frequency domain parameters of HRV were collected in 62 medically healthy individuals, of whom 25 with and 37 without dysphoria.

Results: Somatic, but not cognitive–affective, symptoms of depression were inversely associated with SD of NN intervals (β = -0.476, p < 0.05), number of interval differences of successive NN intervals greater than 50 ms (NN50; β = -0.498, p < 0.03), and HRV total power (β = -0.494, p < 0.04) in the group with dysphoria, after controlling for sex, anxiety, and lifestyle factors. Cognitive–affective and somatic symptoms were not related to any of the HRV parameters in the group without dysphoria (all ps > 0.24).

Conclusion: By showing that the relationship between somatic depressive symptoms and reduced HRV extends to medically healthy individuals with dysphoria, the present findings suggest that this association is independent of factors concomitant with cardiovascular diseases. The present study also suggests that individuals with somatic rather than cognitive–affective subsets of depressive symptoms may be at greater risk for developing cardiovascular diseases.

Utilizing heartbeat evoked potentials to identify cardiac regulation of vagal afferents during emotion and resonant breathing

The importance of the bi-directional communication between the heart and brain has been known for over 100 years (Lane et al. in NeuroImage 44:213-222, 2009a, Psychosom Med 2:117-134, 2009b) and plays an important role in many of the prominent theories of psychophysiology today. Utilizing heartbeat evoked potentials (HEPs), we sought to determine whether heart rate variability (HRV) was related to the strength of the connection between the heart and brain. We also hypothesized that differing emotion states would result in differing amplitudes of HEPs. Participants were induced into emotional states with an autobiographical script of their happiest and saddest memory. HEPs were also recorded during diaphragmatic breathing at six breaths per minute. The evoked potentials during the emotional conditions, especially negative emotion were most attenuated. We believe that the signal from the heart to the brain may be filtered by central limbic structures affecting the level of the signal at the cortex. It also appears that HRV affects the strength of HEPs, especially during resonant breathing. Significant neurocardiac gender differences were also present across all conditions. The results of this study support the theory and speculation of many authors who believe vagal afferents play a role in brain function.

Heart rate variability and treatment outcome in major depression: a pilot study

Variations in heart rate variability (HRV) have been associated with major depressive disorder (MDD), but the relationship of baseline HRV to treatment outcome in MDD is unclear. We conducted a pilot study to examine associations between resting baseline HRV and MDD treatment outcome. We retrospectively tested several parameters of HRV in an MDD treatment study with escitalopram (ESC, N=26) to generate a model of how baseline HRV related to treatment outcome, and cross-validated the model in a separate trial of MDD treatment with Iyengar yoga (IY, N=16). Lower relative power of very low frequency (rVLF) HRV at baseline predicted improvement in depressive symptoms when adjusted for age and gender (R2>.43 and p<0.05 for both trials). Although vagal parasympathetic measures were correlated with antidepressant treatment outcome, their predictive power was not significant after adjusting for age and gender. In conclusion, baseline resting rVLF was associated with depression treatment outcome in two independent MDD treatment studies. These results should be interpreted with caution due to limited sample size, but a strength of this study is its validation of the rVLF predictor in an independent sample. rVLF merits prospective confirmation as a candidate biomarker.

Adolescent girls with emotional disorders have a lower end-tidal CO2 and increased respiratory rate compared with healthy controls

Hyperventilation has been linked to emotional distress in adults. This study investigates end-tidal carbon dioxide (ETCO₂), respiratory rate (RR), and heart rate variability (HRV) in adolescent girls with emotional disorders and healthy controls. ETCO₂, RR, HRV, and ratings of emotional symptom severity were collected in adolescent female psychiatric patients with emotional disorders (n = 63) and healthy controls (n = 62). ETCO₂ and RR differed significantly between patients and controls. ETCO₂, HR, and HRV were significant independent predictors of group status, that is, clinical or healthy, while RR was not. ETCO₂ and RR were significantly related to emotional symptom severity and to HRV in the total group. ETCO₂ and RR were not affected by use of selective serotonin reuptake inhibitors. It is concluded that emotional dysregulation is related to hyperventilation in adolescent girls. Respiratory-based treatments may be relevant to investigate in future research.

Self-Regulatory Deficits Associated with Unpracticed Mindfulness Strategies for Coping with Acute Pain

Training in mindfulness is a well-supported therapeutic strategy for pain conditions, though short-term mindfulness training for acute pain is not always effective. To explore the possibility that initial attempts at mindfulness in people without previous training may drain self-regulatory resources, the current study used a student sample (N=63) to test the hypothesis that brief instruction in mindfulness would lead to reduced pain tolerance on a cold pressor task (CPT), compared to more familiar strategies for coping with acute pain. We also investigated whether high heart rate variability (HRV), a physiological indicator of self-regulatory capacity, would predict pain tolerance. Higher HRV predicted greater pain tolerance only in the control group, suggesting that applying unfamiliar mindfulness strategies while attempting to tolerate pain more rapidly sapped self-regulatory strength.

The effect of anxiety on heart rate variability, depression, and sleep in chronic obstructive pulmonary disease

OBJECTIVES

The current study investigates heart rate variability (HRV) responses to a psychosocial stressor in chronic obstructive pulmonary disease (COPD) patients, and the potential role of anxiety as a confounding factor in this relationship. Additionally, this study also investigates the influence of anxiety on sleep and depressive symptoms among COPD patients.

METHODS

The study utilized a 2 (disease status)×2 (anxiety group) factorial design examining HRV associated with anxiety symptoms and COPD during a standardized acute social stress task. Participants (mean age 59.1±11.2 years; 50% female) completed pulmonary function testing, HRV monitoring, and self-report questionnaires assessing psychological factors. 30 COPD patients were age- and gender-matched with 30 healthy controls.

RESULTS

HRV response to a psychosocial stressor among participants with higher anxiety (both COPD and healthy) reflected autonomic dysregulation in both time and frequency domains that was not evident among non-anxious participants. COPD participants with higher anxiety reported greater symptoms of depression and poorer sleep quality than did COPD participants with low anxiety.

CONCLUSIONS

Anxiety is associated with dysregulated HRV response to a psychosocial stressor, but the negative influence of anxiety and COPD on autonomic function did not appear to be additive. Comorbid anxiety in patients with COPD is associated with increased behavioral and psychological symptoms of distress.

Does respiratory sinus arrhythmia (RSA) predict anxiety reduction during cognitive behavioral therapy (CBT) for social anxiety disorder (SAD)?

Modifying dysfunctional emotion regulation is an important goal in psychological treatments for social anxiety disorder (SAD). Antecedent-focused strategies learned in cognitive behavioral therapy (CBT), such as cognitive reappraisal, have proven more effective in reducing social anxiety than response-focused strategies, such as expressive suppression. Still, not all patients with SAD respond well to CBT. Medications and physiological factors may also influence the clinical response. The purpose of the present study was to examine the role that these factors play in determining treatment response following CBT for SAD. Using multilevel modeling, we examined associations across four separate laboratory visits between change in self-reported anxiety and indices of reappraisal, suppression, medication status, and resting respiratory sinus arrhythmia (RSA), a proxy measure of self-regulatory capacity, in 23 socially anxious adults during a 12-week program of CBT. Most participants were ultimately classified as responders to CBT (n=15), but in some, anxiety levels remained unchanged (n=8). Medication use explained substantial variance related to individual differences in anxiety among participants. When modeled separately, reappraisal, suppression, and RSA each accounted for significant variance related to anxiety. However, the best-fitting model included reappraisal and RSA. Moreover, RSA reactivity (change in RSA levels over time) was more important for predicting anxiety reduction than were baseline levels of RSA. These findings suggest that reappraisal and parasympathetic responsiveness may be important in reducing anxiety in adults with SAD who respond well to CBT.

Heart rate variability in patients with fully remitted major depressive disorder

OBJECTIVE

Cardiac autonomic dysregulation has been reported in major depressive disorder (MDD), but scarce studies investigated that in fully remitted MDD.

METHODS

To examine cardiac autonomic function in remitted MDD, 470 unmedicated individuals with a diagnosis of MDD earlier in life and 462 healthy volunteers, aged 18-65 years, were recruited for a case-control analysis. 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.

RESULTS

In patients with remitted MDD, no differences in RR intervals and all frequency-domain indices of HRV could be detected as compared with controls. Stratified analyses by the presence of a history of suicide ideation (the SI+ vs. the SI-subgroup) revealed decreased cardiac vagal control in the SI+ subgroup. The correlation analysis revealed an inverse relation between HRV levels and the harm avoidance score (which has been suggested to be associated with serotonergic activity), mainly attributable to the robust association in the SI+ subgroup.

CONCLUSION

Our study shows that cardiac autonomic dysregulation is not shown in remitted MDD patients as a whole but is limited to the subgroup of remitted MDD patients with a history of suicidal ideation. In view of the higher risk for cardiac complications in these vulnerable individuals, one might consider the treatment to restore their autonomic function.

Depressive symptoms and autonomic nervous system dysfunction in an elderly population-based study: the PROOF study

BACKGROUND

To assess the relationship between depressive symptoms, evaluated through self-reported history as well as current depressive symptoms, and impaired autonomic nervous system activity, evaluated by long-term heart rate variability and baroreflex sensitivity among elderly community residents, aged 65 years.

METHODS

Subjects from the Proof cohort Study were evaluated for depressive symptoms and self-reported history of depression at inclusion. Autonomic nervous system activity was assessed through 24-h heart rate variability and baroreflex sensitivity. Cross-sectional analyses were performed to study the relationship between the different status of depression and autonomic nervous system activity.

RESULTS

Among the 1011 Proof study participants, 823 subjects were included in the analyses. Current depressive symptoms were present among 67 subjects; history of depression was reported by 228 subjects. Psychoactive drugs were used by 59 subjects. Low frequency (p=0.02), very low frequency (p<0.01) and Low/High frequency ratio (p<0.001) were lower among subjects with depressive symptoms and history of depression, independently of antidepressant treatment. The association remained significant for Low/High frequency ratio after adjustment for gender and physical activity (p=0.004).

CONCLUSION

Current depressive symptoms may be linked to autonomic nervous system lower performances. A possible long-term effect of depressive symptoms at middle-age may influence later-life autonomic nervous system activity. Our results highlight the importance of taking into account the depressive symptoms in the cardiovascular risk, even in the elderly.

Effects of serum calcium and magnesium on heart rate variability in adult women

The present study was designed to evaluate the association of serum calcium (Ca) and magnesium (Mg) levels with heart rate variability (HRV). One hundred and sixteen adult women were recruited in this cross-sectional study. Serum Ca and Mg levels were measured, and HRV in each time and frequency domain was recorded for 5 min. Mean heart rate and standard deviation of the normal to normal interval (SDNN) and root mean square of differences of successive RR interval (RMSSD) in time domain and total power (TP), low-frequency power (LF), high-frequency power (HF), and LF/HF ratio in frequency domain were compared according to the tertiles of serum Ca and Mg levels and Ca/Mg ratio. The associations between serum Ca and Mg levels and Ca/Mg ratio with HRV were evaluated using regression analyses. Mean heart rate tended to increase from the lowest to the highest tertile of Ca levels (p = 0.081), whereas it decreased significantly with higher Mg levels (p = 0.026). Increasing SDNN value was observed from the lowest to the highest tertile of Mg levels (p = 0.009). SDNN value decreased significantly from the lowest to the highest tertile of Ca/Mg ratio (p = 0.030). Participants in the lowest tertile of Ca/Mg ratio had significantly higher TP and LF values compared to those in the middle and highest tertiles (p < 0.05). Decreasing SDNN, TP, and LF values were significantly associated with higher Ca/Mg ratios (p < 0.05). Associations of serum Mg level and Ca/Mg ratio with HRV could be one of the mechanisms involved in cardiovascular diseases.

Mind and heart: heart rate variability in major depressive disorder and coronary heart disease - a review and recommendations

OBJECTIVE

There is a reciprocal association between major depressive disorder (MDD) and coronary heart disease (CHD). These conditions are linked by a causal network of mechanisms. This causal network should be quantitatively studied and it is hypothesised that the investigation of vagal function represents a promising starting point. Heart rate variability (HRV) has been used to investigate cardiac vagal control in the context of MDD and CHD. This review aims to examine the relationship of HRV to both MDD and CHD in the context of vagal function and to make recommendations for clinical practice and research.

METHODS

The search terms 'heart rate variability', 'depression' and 'heart disease' were entered into an electronic multiple database search engine. Abstracts were screened for their relevance and articles were individually selected and collated.

RESULTS

Decreased HRV is found in both MDD and CHD. Both diseases are theorized to disrupt autonomic control feedback loops on the heart and are linked to vagal function. Existing theories link vagal function to both mood and emotion as well as cardiac function. However, several factors can potentially confound HRV measures and would thus impact on a complete understanding of vagal mechanisms in the link between MDD and CHD.

CONCLUSIONS

The quantitative investigation of vagal function using HRV represents a reasonable starting point in the study of the relationship between MDD and CHD. Many psychotropic and cardiac medications have effects on HRV, which may have clinical importance. Future studies of HRV in MDD and CHD should consider antidepressant medication, as well as anxiety, as potential confounders.

How accurate is pulse rate variability as an estimate of heart rate variability? A review on studies comparing photoplethysmographic technology with an electrocardiogram

BACKGROUND

The usefulness of heart rate variability (HRV) as a clinical research and diagnostic tool has been verified in numerous studies. The gold standard technique comprises analyzing time series of RR intervals from an electrocardiographic signal. However, some authors have used pulse cycle intervals instead of RR intervals, as they can be determined from a pulse wave (e.g. a photoplethysmographic) signal. This option is often called pulse rate variability (PRV), and utilizing it could expand the serviceability of pulse oximeters or simplify ambulatory monitoring of HRV.

METHODS

We review studies investigating the accuracy of PRV as an estimate of HRV, regardless of the underlying technology (photoplethysmography, continuous blood pressure monitoring or Finapresi, impedance plethysmography).

RESULTS/CONCLUSIONS

Results speak in favor of sufficient accuracy when subjects are at rest, although many studies suggest that short-term variability is somewhat overestimated by PRV, which reflects coupling effects between respiration and the cardiovascular system. Physical activity and some mental stressors seem to impair the agreement of PRV and HRV, often to an inacceptable extent. Findings regarding the position of the sensor or the detection algorithm are not conclusive. Generally, quantitative conclusions are impeded by the fact that results of different studies are mostly incommensurable due to diverse experimental settings and/or methods of analysis.

Cardio-respiratory coupling in untreated patients with major depression

BACKGROUND

Depressive disorders are known to be associated with higher risks of cardiovascular diseases. Several studies have reported an imbalance within the autonomic nervous system (ANS) as one putative cause. Previous investigations showed decreased cardio-respiratory coupling in depressive patients that were treated with nortriptyline. We aimed to compare parameters of heart rate variability and cardio-respiratory coupling between unmedicated patients suffering from major depressive disorder (MDD) and healthy controls in order to further understand autonomic dysfunction in the disease.

METHODS

We investigated eighteen unmedicated patients with major depressive disorder and eighteen matched healthy controls. Electrocardiogram and respiratory signals were obtained during a twenty minute resting period. Time- and frequency based parameters of HRV, respiratory sinus arrhythmia (RSA), approximate entropy of heart rate (ApEn(RR)) and respiratory rate (ApEn(Resp)) were calculated. Additionally, cross-ApEn between RR-intervals and respiration time series was determined, reflecting coupling of both signals.

RESULTS

Patients showed an increased heart rate and LF/HF-ratio. Respiratory sinus arrhythmia (RSA) and ApEn(RR) were reduced in patients in comparison to controls. Breathing rate, ApEn(Resp) and cross-ApEn did not differ between the two groups.

DISCUSSION

Increased heart rate, increased LF/HF-ratio, reduced RSA and reduced ApEn(RR) indicate a decrease of cardiac vagal modulation in depressive patients. No difference of cardio-respiratory coupling was observed. Respiratory parameters and cross-ApEn did not differ between both groups, and thus we conclude that diminished vagal modulation is mainly limited to cardiac modulation.

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.

Predicting maternal sensitivity: The roles of postnatal depressive symptoms and parasympathetic dysregulation

Previous research has established that maternal depression is a risk factor for a variety of negative developmental outcomes among infants and children. Although low levels of maternal sensitivity have been hypothesized to explain this risk, the biological mechanisms underlying the association between maternal depressive symptoms and low levels of maternal sensitivity have been largely underexplored. This study examined the roles of postnatal depressive symptoms and parasympathetic nervous system functioning as predictors of low levels of maternal sensitivity, during a stressful mother-infant interaction-the reunion phase of the Still-Face Paradigm. Depressive symptoms and traitlike predispositions toward parasympathetic dysregulation, as indexed by low resting levels of respiratory sinus arrhythmia, were associated independently with less sensitive parenting. Discussion considers that during stressful mother-infant interactions, both mothers with depressive symptoms and mothers predisposed to parasympathetic dysregulation may have fewer emotional, physiological, and psychological resources with which to respond sensitively to their infants' cues.