Anxiety reduces baroreflex cardiac control in older adults with major depression

Higher Cardiovagal Baroreflex Sensitivity Predicts Increased Pain Outcomes After Cardiothoracic Surgery

Excessive postoperative pain can lead to extended hospitalization and increased expenses, but factors that predict its severity are still unclear. Baroreceptor function could influence postoperative pain by modulating nociceptive processing and vagal-mediated anti-inflammatory reflexes. To investigate this relationship, we conducted a study with 55 patients undergoing minimally invasive cardiothoracic surgery to evaluate whether cardiovagal baroreflex sensitivity (BRS) can predict postoperative pain. We assessed the spontaneous cardiovagal BRS under resting pain-free conditions before surgery. We estimated postoperative pain outcomes with the Pain, Enjoyment, and General Activity scale and pressure pain thresholds on the first (POD1) and second (POD2) postoperative days and persistent pain 3 and 6 months after hospital discharge. We also measured circulating levels of relevant inflammatory biomarkers (C-reactive protein, albumin, cytokines) at baseline, POD1, and POD2 to assess the contribution of inflammation to the relationship between BRS and postoperative pain. Our mixed-effects model analysis showed a significant main effect of preoperative BRS on postoperative pain (P = .013). Linear regression analysis revealed a significant positive association between preoperative BRS and postoperative pain on POD2, even after adjusting for demographic, surgical, analgesic treatment, and psychological factors. Moreover, preoperative BRS was linked to pain interfering with general activity and enjoyment but not with other pain parameters (pain intensity and pressure pain thresholds). Preoperative BRS had modest associations with postoperative C-reactive protein and IL-10 levels, but they did not mediate its relationship with postoperative pain. These findings indicate that preoperative BRS can independently predict postoperative pain, which could serve as a modifiable criterion for optimizing postoperative pain management. PERSPECTIVE: This article shows that preoperative BRS predicts postoperative pain outcomes independently of the inflammatory response and pain sensitivity to noxious pressure stimulation. These results provide valuable insights into the role of baroreceptors in pain and suggest a helpful tool for improving postoperative pain management.

A Study of Brain Function Characteristics of Service Members at High Risk for Accidents in the Military

Military accidents are often associated with stress and depressive psychological conditions among soldiers, and they often fail to adapt to military life. Therefore, this study analyzes whether there are differences in EEG and pulse wave indices between general soldiers and three groups of soldiers who have not adapted to military life and are at risk of accidents. Data collection was carried out using a questionnaire and a device that can measure EEG and pulse waves, and data analysis was performed using SPSS. The results showed that the concentration level and brain activity indices were higher in the general soldiers and the soldiers in the first stage of accident risk. The body stress index was higher for each stage of accident risk, and the physical vitality index was higher for general soldiers. Therefore, it can be seen that soldiers who have not adapted to military life and are at risk of accidents have somewhat lower concentration and brain activity than general soldiers, and have symptoms of stress and lethargy. The results of this study will contribute to reducing human accidents through EEG and pulse wave measurements not only in the military but also in occupations with a high risk of accidents such as construction.

Impact of antidepressant use on the autonomic nervous system: A meta-analysis and systematic review

Changes in cardiac autonomic nervous system (ANS) regulation observed in psychiatric disorders may be mitigated by antidepressants. We meta-analyzed and systematically reviewed studies examining antidepressants' effects on ANS outcomes, including heart rate variability (HRV). We conducted a PRISMA/MOOSE-compliant search of PubMed and Scopus until March 28th, 2022. We included randomized placebo-controlled trials (RCTs) and pre-post studies, regardless of diagnosis. We pooled results in random-effects meta-analyses, pooling homogeneous study designs and outcomes. We conducted sensitivity analyses and assessed quality of included studies. Thirty studies could be meta-analyzed. Selective serotonin reuptake inhibitors (SSRIs) were significantly associated with a reduction in the square root of the mean-squared difference between successive R-R intervals (RMSSD) (SMD= -0.48) and skin conductance response (SMD= -0.55) in RCTs and with a significant increase in RMSSD in pre-post studies (SMD=0.27). In pre-post studies, tricyclic antidepressants (TCAs) were associated with a significant decrease in several HRV outcomes while agomelatine was associated with a significant increase in high frequency power (SMD= 0.14). In conclusion, SSRIs reduce skin conductance response but have no or inconclusive effects on other ANS outcomes, depending on study design. TCAs reduce markers of parasympathetic function while agomelatine might have the opposite effect. Studies are needed to investigate the impact of SSRIs on the recovery of cardiac ANS regulation after acute myocardial infarction, and the effects of newer antidepressants.

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.

Baroreflex sensitivity derived from the Valsalva manoeuvre: A physiological protective factor for anxiety induced by breathing CO2-enriched air

This study aimed to determine the capacity of baroreflex sensitivity, derived from the Valsalva manoeuvre (BRS_v), to predict state anxiety induced by a biological stressor (CO₂ inhalation). Healthy adults (n = 50) breathed 7.5 % CO₂-enriched air for 8 min, preceded and followed by breathing medical air for 5 min. State anxiety was evaluated with a visual analogue scale. Anxiety sensitivity (Anxiety Sensitivity Index-3; ASI-3) and trait anxiety (Trait form of the State-Trait Anxiety Inventory; STAI_T) served as cognitive-affective predictors. BRS_v was adopted as a physiological predictor. Multiple regression analysis revealed that BRS_v predicted lower anxiety during CO₂ exposure, and attenuated the effect of ASI-3 in increasing anxiety. No significant effects were found for STAI_T. This is the first study to identify baroreflex sensitivity as a strong protective physiological factor for anxiety beyond the effect of anxiety sensitivity.

The impact of self-reported levels of anxiety on respiratory sinus arrhythmia levels in adults who stutter

PURPOSE

This study investigated whether subjective levels of anxiety predict respiratory sinus arrythmia (RSA) levels in adults who stutter (AWS) compared to (ANS) during baseline and social stress situations.

METHODS

Participants were eight AWS and 10 ANS who performed a modified version of the Trier Social Stress Test (TSST-M). For this, participants were required to prepare and deliver a 5-minute speech and perform a nonword reading task in front of what was perceived as a group of professionals trained in public speaking. Measures of respiratory sinus arrhythmia (RSA) were calculated for baseline and TSST-M conditions. Participants also completed the State-Trait Anxiety Inventory (STAI), both the trait (STAI-T) and state (STAI-S) portion, which served as subjective anxiety ratings. Univariate analyses of variances (UNIANOVA) were used to assess the effects of the STAI-T and STAI-S anxiety on respiratory sinus arrhythmia (RSA) levels at pre-stress and TSST-M conditions. RSA, an index of parasympathetic nervous system activity, is considered to be a measure of emotional regulation. The strength of the effects of STAI-T and STAI-S on RSA levels was evaluated with the unstandardized coefficients for each group separately.

RESULTS

Results showed a significant difference between groups for the effects of STAI-T on RSA values for the pre-stress nonword reading task. No other significant differences were found between groups for the pre-stress or TSST-M conditions. Slope estimates showed that STAI-T was a significant predictor of RSA values for pre-stress speaking conditions for the AWS but not ANS. No significant fixed effects or interaction effects were found for the STAI-S and RSA levels in the AWS or ANS. Nor were there significant effects of STAI-T on RSA levels in the AWS or ANS for TSST-M conditions. Descriptive analysis revealed the effects found in the AWS during pre-stress conditions were attributed to a subgroup of AWS who reported low self-reports of anxiety (i.e. STAI-T) and high levels of emotional regulation (i.e. RSA) across social stress conditions.

DISCUSSION

Low self-reported STAI-T scores simultaneous with high RSA levels in some AWS may reflect a self-regulatory strategy adapted in response to chronic, daily stress associated with stuttering.

The cardiac, vasomotor, and myocardial branches of the baroreflex in fibromyalgia: Associations with pain, affective impairments, sleep problems, and fatigue

This study investigated the cardiac, vasomotor, and myocardial branches of the baroreflex in fibromyalgia using the spontaneous sequence method. Systolic blood pressure (SBP), interbeat interval (IBI), stroke volume (SV), pre-ejection period (PEP), and total peripheral resistance (TPR) were continuously recorded in 40 fibromyalgia patients and 30 healthy individuals during a cold pressor test and a mental arithmetic task. Sequences of covariation between SBP and IBI (cardiac branch), SV and PEP (myocardial branch), and TPR (vasomotor branch) were identified. Baroreflex sensitivity (BRS) was represented by the slope of the regression line between values in the sequences; baroreflex effectiveness (BEI) was indexed by the proportion of progressive SBP changes that elicited reflex responses. Patients exhibited lower BRS in the three branches, lower BEI in the cardiac and vasomotor branches, and reduced reactivity in cardiac BRS and BEI, SBP, IBI, SV, and PEP. Moreover, BRS and BEI were inversely related to clinical pain, cold pressor pain, depression, trait anxiety, sleep problems, and fatigue. Reduced function of the three baroreflex branches implies diminished resources for autonomic inotropic, chronotropic, and vascular regulation in fibromyalgia. Blunted stress reactivity indicates a limited capacity for autonomic cardiovascular adjustment to situational requirements. The associations of BRS and BEI with pain perception may reflect the antinociceptive effects arising from baroreceptor afferents, where reduced baroreflex function may contribute to the hyperalgesia characterizing fibromyalgia. The associations with affective impairments, sleep problems, and fatigue suggest that baroreflex dysfunctions are also involved in the secondary symptoms of the disorder.

Higher Anxiety Is Associated with Lower Cardiovascular Autonomic Function in Female Twins

Anxiety symptoms co-occur with cardiovascular health problems, with increasing evidence suggesting the role of autonomic dysfunction. Yet, there is limited behavior genetic research on underlying mechanisms. In this twin study, we investigated the phenotypic, genetic and environmental associations between a latent anxiety factor and three cardiovascular autonomic function factors: interbeat interval (IBI, time between heart beats), heart rate variability (HRV, overall fluctuation of heart-beat intervals) and baroreflex sensitivity (BRS, efficiency in regulating blood pressure [BP]). Multivariate twin models were fit using data of female twins (N = 250) of the Twin Interdisciplinary Neuroticism Study (TWINS). A significant negative association was identified between latent anxiety and BRS factors (r = -.24, 95% CI [-.40, -.07]). Findings suggest that this relationship was mostly explained by correlated shared environmental influences, and there was no evidence for pleiotropic genetic or unique environmental effects. We also identified negative relationships between anxiety symptoms and HRV (r = -.17, 95% CI [-.34, .00]) and IBI factors (r = -.13, 95% CI [-.29, .04]), though these associations did not reach statistical significance. Findings implicate that higher anxiety scores are associated with decreased efficiency in short-term BP regulation, providing support for autonomic dysfunction with anxiety symptomatology. The baroreflex system may be a key mechanism underlying the anxiety-cardiovascular health relationship.

Heart Rate Variability for the Prediction of Treatment Response in Major Depressive Disorder

Major depressive disorder (MDD) is one of the disabling diseases in the world-wide, and known to increase cardiac morbidity and mortality. Therefore, previous studies related heart rate variability (HRV) have been conducted to evaluate and diagnose MDD, and to predict treatment outcomes in patient with MDD. We reviewed extensively on the previous peer-reviewed publications associated with this issue, using Pub-Med. In this review article, we introduce the basic concept of HRV and HRV measures, and present several important findings associated with diagnosis and treatment prediction in MDD with using HRV parameters. Furthermore, we discuss the possible underlying mechanism of this phenomenon, and suggest several considerations for the future research.

Heart rate variability as a biomarker of anxious depression response to antidepressant medication

BACKGROUND

There is a need to identify biomarkers of treatment outcomes for major depressive disorder (MDD) that can be disseminated. We investigated the predictive utility of pretreatment heart rate variability (HRV) for outcomes of antidepressant medication in MDD, with pretreatment anxious depression as a hypothesized moderator of HRV effects.

METHODS

A large, randomized, multicenter practical trial (International Study to Predict Optimized Treatment in Depression) in patients with current nonpsychotic MDD (N = 1,008; 722 completers) had three arms: escitalopram, sertraline, and venlafaxine-extended release. At pretreatment, patients were defined as having anxious (N = 309) versus nonanxious (N = 413) depression and their resting high-frequency HRV (root mean square of successive differences) was assessed. Patients' usual treating clinicians managed medication. At 8 weeks, primary outcomes were clinician-rated depressive symptom response and remission; secondary outcomes were self-reported response and remission.

RESULTS

Pretreatment HRV predicted antidepressant outcomes as a function of anxious versus nonanxious depression. In anxious depression, patients with higher HRV had better outcomes, whereas patients with lower HRV had poorer outcomes. In nonanxious depression, patients with lower HRV had better outcomes, whereas patients with higher HRV had poorer outcomes. Some simple effects were not significant. Results did not differ by treatment arm and remained significant when controlling for important covariates.

CONCLUSIONS

These findings inform a precision medicine approach in which clinical and biological assessments may be integrated to facilitate treatment outcome prediction. Knowing about HRV may help determine which patients with anxious depression could benefit from antidepressants and which patients may require a different treatment approach.

Evaluation of an Integrated System of Wearable Physiological Sensors for Stress Monitoring in Working Environments by Using Biological Markers

OBJECTIVE

The objectives of this paper are to develop and test the ability of a wearable physiological sensors system, based on ECG, EDA, and EEG, to capture human stress and to assess whether the detected changes in physiological signals correlate with changes in salivary cortisol level, which is a reliable, objective biomarker of stress.

METHODS

15 healthy participants, eight males and seven females, mean age 40.8 ± 9.5 years, wore a set of three commercial sensors to record physiological signals during the Maastricht Acute Stress Test, an experimental protocol known to elicit robust physical and mental stress in humans. Salivary samples were collected throughout the different phases of the test. Statistical analysis was performed using a support vector machine (SVM) classification algorithm. A correlation analysis between extracted physiological features and salivary cortisol levels was also performed.

RESULTS

15 features extracted from heart rate variability, electrodermal, and electroencephalography signals showed a high degree of significance in disentangling stress from a relaxed state. The classification algorithm, based on significant features, provided satisfactory outcomes with 86% accuracy. Furthermore, correlation analysis showed that the observed changes in physiological features were consistent with the trend of salivary cortisol levels (R² = 0.714).

CONCLUSION

The tested set of wearable sensors was able to successfully capture human stress and quantify stress level.

SIGNIFICANCE

The results of this pilot study may be useful in designing portable and remote control systems, such as medical devices used to turn on interventions and prevent stress consequences.

Pharmaceutically treated anxiety but not depression prior to cancer diagnosis predicts the onset of cardiovascular disease among breast cancer survivors

PURPOSE

To examine the associations between pharmaceutically treated anxiety and depression present in the year prior to breast cancer diagnosis and the risk of incident cardiovascular disease (CVD), while controlling for traditional cardiovascular risk factors and clinical characteristics in a population-based observational study.

METHODS

Adult 1-year breast cancer survivors (n = 7227), diagnosed between 01-01-1999 and 12-31-2010, with no history of CVD, were selected from the Netherlands Cancer Registry. Drug dispensing data were derived from the PHARMO Database Network and used as proxy for CVD, anxiety, and depression. By multivariable Cox regression analysis, we examined the risk associated with pharmaceutically treated anxiety and depression for developing CVD after cancer diagnosis, adjusting for age, pharmaceutically treated hypertension, hypercholesterolemia, and diabetes mellitus in the year prior to cancer diagnosis, tumor stage, and cancer treatment.

RESULTS

During the 13-year follow-up period, 193 (3%) breast cancer survivors developed CVD. Women pharmaceutically treated for anxiety in the year prior to their cancer diagnosis had a 48% increased hazard for CVD [HR = 1.48; 95% CI 1.05-1.08] after full adjustment. This association was restricted to breast cancer survivors who were 65 years or younger. Depression was not associated with CVD risk [HR = 0.89; 95% CI 0.52-1.53]. Older age [HR = 1.06; 95% CI 1.05-1.08], hypertension [HR = 1.80; 95% CI 1.32-2.46], and hypercholesterolemia [HR = 1.63; 95% CI 1.15-2.33] were associated with an increased hazard for incident CVD, whereas hormone therapy [HR = 0.59; 95% CI 0.42-0.83] was protective.

CONCLUSIONS

Anxiety present in the year prior to breast cancer diagnosis increases the risk of incident CVD in 1-year breast cancer survivors, after adjustment for depression, traditional cardiovascular risk factors, and clinical characteristics.

Affective impairment in chronic low blood pressure

OBJECTIVE

Physical complaints such as faintness, dizziness, cold limbs and headaches have been well-established in chronic low blood pressure (hypotension). This study investigated the occurrence of adverse emotional states and the symptoms of depression in this condition. As autonomic dysregulation, particularly diminished sympathetic tone, is believed to be involved in the etiology of hypotension, the impact of different facets of autonomic cardiovascular control on mood and depressive symptoms was also explored.

METHODS

Forty individuals with chronic hypotension and forty normotensive control persons were presented with the Mood Scale and Beck Depression Inventory. Stroke volume, cardiac output, pre-ejection period, Heather index and aortic peak blood flow velocity were recorded under resting conditions as indices of beta-adrenergic inotropic drive. Respiratory sinus arrhythmia and baroreflex sensitivity were additionally obtained.

RESULTS

Hypotensive individuals scored markedly higher on both questionnaire scales than controls, indicating an adversely affected emotional state and more severe depressive symptoms. In the entire sample, cardiac output, Heather index, and aortic peak blood flow velocity correlated negatively with the questionnaire scores; according to regression analysis, the Heather index explained the largest proportion of test score variance.

CONCLUSION

Although hypotension does not constitute a serious medical condition, the findings of an adverse affective state and increased burden with depressive symptoms corroborate the view that it can have a considerable impact on wellbeing and quality of life. The correlations of the beta-adrenergic indices with the questionnaire scales indicate that cardiac sympathetic regulation plays a key role in the psychophysiological mediation of hypotension-related mood impairment.

Cardiovascular co-morbidity in cancer patients: the role of psychological distress

Due to aging of the population and cardiotoxic cancer treatment, there is an increasing group of patients with cancer and co-morbid cardiovascular disease (CVD). In order to find a balance between the risk of undertreating the malignancy on the one hand and inducing CVD on the other hand, CVD risk stratification at the time of cancer diagnosis and knowledge on the pathway for developing incident CVD in cancer patients is vital. In this paper, we propose an adapted multiple-hit hypothesis for developing CVD in cancer patients describing that patients with cancer are exposed to a series of sequential or concurrent events that together make them more vulnerable to reduced cardiovascular reserves, development of incident CVD and ultimately death. We highlight the possible impact of psychological distress secondary to a cancer diagnosis and/or treatment, which in turn may increase the risk of incident CVD in patients diagnosed with cancer. Furthermore, we discuss potential behavioral and pathophysiological mechanisms underlying the link between psychological distress and the pathophysiology of incident CVD. In addition, key unanswered questions for future research are posed. In the future, researching the adapted multiple-hit hypothesis for developing CVD among cancer patients will hopefully advance the care of cancer patients by finding some of the missing pieces of the puzzle. To do so, we need to focus on minimizing cardiovascular risk and promoting cardiovascular health in cancer patients by addressing the knowledge gaps formulated in this paper.

The Relationships Between Parasympathetic Function and Pain Perception: The Role of Anxiety

BACKGROUND

Previous studies have identified relationships between autonomic function and pain perception. Anxiety was found to influence both autonomic and pain responses. We examined the effect of anxiety level on parasympathetic function and pain perception as well as on the relationships between these 2 systems.

METHODS

Thirty healthy females were divided into high- and low-anxiety groups according to their trait anxiety levels. Parasympathetic function was obtained using heart rate variability, deep breathing, and Valsalva ratios. Pain perception parameters of heat pain thresholds, pain rating of supra-thresholds stimulus, mechanical temporal summation, and conditioned pain modulation response were examined.

RESULTS

The low-anxiety and high-anxiety groups exhibited no significant differences in the parasympathetic function and pain perception parameters. Assessment of the associations revealed that in the high-anxiety group, higher mean ratings of the tonic heat pain stimulus were significantly correlated with higher rMSSD (r² = 0.358, P = 0.019), but this was not found for the low-anxiety group (P = 0.282). In addition, in the high-anxiety group, efficient conditioned pain modulation response was correlated with higher deep breathing ratio (r² = 0.363, P = 0.023); however, in the low-anxiety group, the correlation did not reach significance (P = 0.109).

CONCLUSIONS

This study demonstrates the role of anxiety level on the relationships between parasympathetic function and pain perception. We suggest that a situation of high anxiety leads to higher norepinephrine levels that can influence both parasympathetic function and pain perception, thus explaining the significant relationships found between these 2 systems only in subjects with high anxiety.

Integrating affective and cognitive correlates of heart rate variability: A structural equation modeling approach

High frequency heart rate variability (HRV) is a measure of neurocardiac communication thought to reflect predominantly parasympathetic cardiac regulation. Low HRV has been associated empirically with clinical and subclinical levels of anxiety and depression and, more recently, high levels of HRV have been associated with better performance on some measures of executive functioning (EF). These findings have offered support for theories proposing HRV as an index measure of a broad, self-regulatory capacity underlying aspects of emotion regulation and executive control. This study sought to test that proposition by using a structural equation modeling approach to examine the relationships of HRV to negative affect (NA) and EF in a large sample of U.S. adults ages 30s-80s. HRV was modeled as a predictor of an NA factor (self-reported trait anxiety and depression symptoms) and an EF factor (performance on three neuropsychological tests tapping facets of executive abilities). Alternative models also were tested to determine the utility of HRV for predicting NA and EF, with and without statistical control of demographic and health-related covariates. In the initial structural model, HRV showed a significant positive relationship to EF and a nonsignificant relationship to NA. In a covariate-adjusted model, HRV's associations with both constructs were nonsignificant. Age emerged as the only significant predictor of NA and EF in the final model, showing inverse relationships to both. Findings may reflect population and methodological differences from prior research; they also suggest refinements to the interpretations of earlier findings and theoretical claims regarding HRV.

Examining the relation between respiratory sinus arrhythmia and depressive symptoms in emerging adults: A longitudinal study

Major depressive disorder (MDD) is a debilitating and prevalent disorder associated with lower quality of life and substantial economic burden. Recently, there has been strong interest in respiratory sinus arrhythmia (RSA) as a biological predictor of later depression. Theoretical work suggests that higher resting RSA indexes physiological flexibility and better emotion regulation whereas lower RSA may mark vulnerability for psychopathology. However, empirical findings have varied. This study examined whether lower resting RSA predicted later depressive symptoms in a sample of healthy young adults across one year (n=185). Results indicate that year one (Y1) resting RSA predicted Y2 depressive symptoms. This finding remained significant when accounting for the stability of RSA and depressive symptoms across both time points and when including trait anxiety, body mass index, and medication use in statistical models. Findings provide further support for RSA as a promising biological marker for understanding and predicting depressive symptoms.

Depressive symptomatology and respiratory sinus arrhythmia in a non-clinical sample of middle-aged African Americans

Decreased heart rate variability and depression are both independent risk factors for cardiac mortality in clinical and non-clinical samples. The purpose of the current study is to examine the hypothesis that severity of depressive symptomatology is inversely associated with respiratory sinus arrhythmia (RSA) in a non-clinical sample of African Americans. The sample included 77 African Americans with a mean age of 48.4 (SD = 11.7). Participants completed the Beck Depression Inventory-II (BDI-II) and a 5-min resting baseline measurement of RSA was collected. The BDI-II total score was positively associated with RSA (β = .334, p = .008). Given the unexpected direction of the association, we separated the BDI-II into cognitive and somatic affective subscales to identify which construct was driving the relationship. The somatic affective, was related to RSA (β = .328, p = .010), but not the cognitive subscale. Given this unexpected positive result, future research should further examine the nature of the relationship between depressive symptomatology and RSA in African Americans, as the relationship may vary based on levels of depressive symptomatology.

Investigating the Effect of Mindfulness Training on Heart Rate Variability in Mental Health Outpatients: A Pilot Study

Depression is associated with increased cardiac morbidity and mortality in people with and without cardiac risk factors, and this relationship is, in part, mediated by heart rate variability (HRV). Increased heart rate and reduced HRV are common in depressed patients, which may explain their higher cardiac risk. This pilot study investigated whether mindfulness-based cognitive therapy (MBCT) promoted objective changes in (1) HRV, and (2) depressive symptoms and quality of life, in mental health outpatients. Twenty-seven adults meeting criteria for DSM-IV Axis I disorders completed an 8-week MBCT program. Data were collected on three occasions, 8 weeks apart; twice before and once after MBCT. Participants completed the Short Form-36 and the Center for Epidemiological Studies Depression Scale (CES-D) at each test period. Heart rate and HRV were measured during electrocardiographic monitoring before and after a cognitive stressor. At baseline, 78% of participants met criteria for depression (CES-D ≥16). Multivariate analyses revealed a significant treatment effect for SF-36 physical summary score and depression (as a dichotomous variable), but not for HRV. This pilot study highlights the immediate psychological and health benefits of MBCT. Low power may have influenced the lack of a finding of an association between HRV and MBCT. However, the feasibility of the study design has been established, and supports the need for larger and longer-term studies of the potential physiological benefits of MBCT for cardiac health.

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.

Yoga as a complementary treatment of depression: effects of traits and moods on treatment outcome

Preliminary findings support the potential of yoga as a complementary treatment of depressed patients who are taking anti-depressant medications but who are only in partial remission. The purpose of this article is to present further data on the intervention, focusing on individual differences in psychological, emotional and biological processes affecting treatment outcome. Twenty-seven women and 10 men were enrolled in the study, of whom 17 completed the intervention and pre- and post-intervention assessment data. The intervention consisted of 20 classes led by senior Iyengar yoga teachers, in three courses of 20 yoga classes each. All participants were diagnosed with unipolar major depression in partial remission. Psychological and biological characteristics were assessed pre- and post-intervention, and participants rated their mood states before and after each class. Significant reductions were shown for depression, anger, anxiety, neurotic symptoms and low frequency heart rate variability in the 17 completers. Eleven out of these completers achieved remission levels post-intervention. Participants who remitted differed from the non-remitters at intake on several traits and on physiological measures indicative of a greater capacity for emotional regulation. Moods improved from before to after the yoga classes. Yoga appears to be a promising intervention for depression; it is cost-effective and easy to implement. It produces many beneficial emotional, psychological and biological effects, as supported by observations in this study. The physiological methods are especially useful as they provide objective markers of the processes and effectiveness of treatment. These observations may help guide further clinical application of yoga in depression and other mental health disorders, and future research on the processes and mechanisms.

Anxiety, depression and autonomic nervous system dysfunction in hypertension

OBJECTIVES

This study examined the relationship between autonomic nervous system dysfunction, anxiety and depression in untreated hypertension.

PATIENTS AND METHODS

86 newly diagnosed hypertensive patients and 98 healthy volunteers were included in the study. The psychological parameters were assessed with Spielberger State-Trait Anxiety Inventory and Beck Depression Inventory by a skilled psychologist. Autonomic parameters were examined during tilt table examination (10min lying position, 10min passive tilt). Heart rate variability (HRV) was calculated by autoregressive methods. Baroreflex sensitivity (BRS) was calculated by non-invasive sequence method from the recorded beat to beat blood pressure values and RR intervals.

RESULTS

Significantly higher state (42.6±9.3 vs. 39.6±10.7 p=0.05) and trait (40.1±8.9 vs. 35.1±8.6, p<0.0001) anxiety scores were found in the hypertension group. There was no statistically significant difference in the depression level. LF-RRI (Low Frequency-RR interval) of HRV in passive tilt (377.3±430.6 vs. 494.1±547, p=0.049) and mean BRS slope (11.4±5.5 vs. 13.2±6.4, p=0.07) in lying position were lower in hypertensives. Trait anxiety score correlates significantly with sympatho/vagal balance (LF/HF-RRI) in passive tilt position (Spearman R=-0.286, p=0.01).

CONCLUSIONS

Anxiety could play a more important role than depression in the development of hypertension. Altered autonomic control of the heart could be one of the pathophysiological links between hypertension and psychological factors.

Heart Rate Variability, Homeostasis, and Brain Function

Measures of heart rate variability (HRV) are major indices of the sympathovagal balance in cardiovascular research. These measures are thought to reflect complex patterns of brain activation as well and HRV is now emerging as a descriptor thought to provide information on the nervous system organization of homeostatic responses in accordance with the situational requirements. Current models of integration equate HRV to the affective states as parallel outputs of the central autonomic network, with HRV reflecting its organization of affective, physiological, “cognitive,” and behavioral elements into a homeostatic response. Clinical application is in the study of patients with psychiatric disorders, traumatic brain injury, impaired emotion-specific processing, personality, and communication disorders. HRV responses to highly emotional sensory inputs have been identified in subjects in vegetative state and in healthy or brain injured subjects processing complex sensory stimuli. In this respect, HRV measurements can provide additional information on the brain functional setup in the severely brain damaged and would provide researchers with a suitable approach in the absence of conscious behavior or whenever complex experimental conditions and data collection are impracticable, as it is the case, for example, in intensive care units.

Chair massage for treating anxiety in patients withdrawing from psychoactive drugs

CONTEXT

Therapeutic massage has been proven to be an effective, nonpharmacologic, alternative for managing state and trait anxiety in a variety of clinical situations. However, no controlled study has investigated this effect in an addiction treatment setting.

AIM

The aim of this study was to investigate the effectiveness of chair massage for reducing anxiety in persons participating in an inpatient withdrawal management program for psychoactive drugs.

DESIGN

The design was a randomized, controlled clinical trial conducted from June 2008 to January 2009.

SUBJECTS

Eighty-two (82) adult patients received inpatient treatment for psychoactive drug withdrawal (alcohol, cocaine, and opiates).

SETTING

This study was conducted at the Withdrawal Management Services at the Capital District Health Authority, Halifax, Nova Scotia.

INTERVENTIONS

Subjects were randomly assigned to receive chair massage (n = 40) or a relaxation control condition (n = 42). Treatments were offered for 3 consecutive days. Standard counseling and pharmacologic management were also offered concurrently to patients in all conditions.

MEASUREMENTS

The primary outcome measure was anxiety assessed using the Spielberger State-Trait Anxiety Inventory (STAI). State and trait anxiety scores were determined immediately prior to and following each treatment intervention.

RESULTS

Analysis of STAI scores showed a significant reduction in state and trait anxiety for both interventions (p < 0.001). The magnitude in the reduction in state (p = 0.001) and trait (p = 0.045) anxiety was significantly greater in the chair massage group where the effect on state anxiety was sustained, at least in part, for 24 hours.

CONCLUSIONS

Within the clinical context of this study, chair massage was more effective that relaxation control in reducing anxiety. Further investigation of chair massage as a potential nonpharmacologic adjunct in the management of withdrawal related anxiety is warranted.

Depressive symptoms, trait aggression, and cardiovascular reactivity to a laboratory stressor

BACKGROUND

Depression and anger/aggression-related traits are thought to promote coronary disease, at least in part, through their associations with stress-related cardiovascular processes. It is unclear whether the effects of these factors on cardiovascular reactivity (CVR) are redundant, additive, or synergistic.

PURPOSE

The main goal of this study was to examine the independent and interactive effects of depressive symptoms and anger/aggression-related traits in promoting CVR.

METHODS

Participants were 63 healthy females who completed the Beck Depression Inventory and Buss-Perry Aggression Questionnaire and performed a stressful speaking task. Systolic and diastolic blood pressure (SBP and DBP) and heart rate were recorded.

RESULTS

Significant interaction effects indicated that depressive symptoms were positively associated with SBP and DBP reactivity among women high in verbal aggression but not among those low in verbal aggression.

CONCLUSIONS

Depressive symptoms and verbal aggression may interact to promote exaggerated blood pressure responses to stressors, a possible marker for mechanisms that contribute to heart disease.

Impact of depression and antidepressant treatment on heart rate variability: a review and meta-analysis

BACKGROUND

Depression is associated with an increase in the likelihood of cardiac events; however, studies investigating the relationship between depression and heart rate variability (HRV) have generally focused on patients with cardiovascular disease (CVD). The objective of the current report is to examine with meta-analysis the impact of depression and antidepressant treatment on HRV in depressed patients without CVD.

METHODS

Studies comparing 1) HRV in patients with major depressive disorder and healthy control subjects and 2) the HRV of patients with major depressive disorder before and after treatment were considered for meta-analysis.

RESULTS

Meta-analyses were based on 18 articles that met inclusion criteria, comprising a total of 673 depressed participants and 407 healthy comparison participants. Participants with depression had lower HRV (time frequency: Hedges' g = -.301, p < .001; high frequency: Hedges' g = -.293, p < .001; nonlinear: Hedges' g = -1.955, p = .05; Valsalva ratio: Hedges' g = -.712, p < .001) than healthy control subjects, and depression severity was negatively correlated with HRV (r = -.354, p < .001). Tricyclic medication decreased HRV, although serotonin reuptake inhibitors, mirtazapine, and nefazodone had no significant impact on HRV despite patient response to treatment.

CONCLUSIONS

Depression without CVD is associated with reduced HRV, which decreases with increasing depression severity, most apparent with nonlinear measures of HRV. Critically, a variety of antidepressant treatments do not resolve these decreases despite resolution of symptoms, highlighting that antidepressant medications might not have HRV-mediated cardioprotective effects and the need to identify individuals at risk among patients in remission.

Heart rate variability (HRV) in adolescent females with anxiety disorders and major depressive disorder

Aim:

The aim of this study was to investigate heart rate variability (HRV) in a clinical sample of female adolescents with anxiety disorders (AD) and/or major depressive disorder (MDD) compared with healthy controls and to assess the effect of selective serotonin reuptake inhibitors (SSRI) on HRV.

Methods:

Heart rate variability was measured in adolescent female psychiatric patients with AD and/or MDD (n = 69), mean age 16.8 years (range: 14.5–18.4), from 13 out-patient clinics and in healthy controls (n = 65), mean age 16.5 years (range: 15.9–17.7). HRV was registered in the sitting position during 4 min with no interventions.

Results:

Logarithmically transformed high frequency HRV (HF), low frequency HRV (LF) and standard deviation of inter beat intervals (SDNN) were lower in the clinical sample compared with the controls (Cohen’s d for HF = 0.57, LF = 0.55, SDNN = 0.60). This was not explained by body mass index, blood pressure or physical activity. Medication with SSRI explained 15.5% of the total variance of HF, 3.0% of LF and 6.5% of SDNN.

Conclusions:

Adolescent female psychiatric patients with AD and/or MDD show reduced HRV compared with healthy controls. Medication with SSRI explained a part of this difference.

Effect of lecturing to 200 students on heart rate variability and alpha-amylase activity

The aim of this study was to examine cardiovascular [heart rate variability (HRV)] and autonomic nervous system activation (by evaluating salivary alpha-amylase activity) that occur in professors both to, and after, the delivery of a lecture to 200 students and to determine whether gender is an influencing factor upon response. Fifty-two participants (26 women and 26 men) collected eight unstimulated saliva samples on 2 days (one a working day on which the lecture was given, the other a non-work or rest day). They also completed the Trait version of the State-Trait Anxiety Inventory (STAI) to assess their dispositional anxiety on the rest day and the State section of the STAI 15 min before and 10 min after their lecture, repeated at the same hour on the control (rest) day. The Perceived Stress Scale (PSS) was also recorded 15 min before the lecture. Continuous RR intervals were recorded before and after the lecture and the following HRV parameters were calculated: total spectral power (P (TOT)); the spectral power of the low frequency component (P (LF)); the high frequency component (P (HF)); and the ratio LF/HF. A reduction (P < 0.05) in the HF and HFnu component of HRV and an increase in the LH/HF ratio (P < 0.05) were observed at the end of the lecture. AA activity measured on the teaching day was significantly higher than that noted on the resting day. Lecturing resulted in a significant increase in the secretion of the stress marker alpha-amylase. Men and women did not differ in trait and state anxiety and no gender differences for HRV or AA activity were found.

Preadolescents' somatic and cognitive-affective depressive symptoms are differentially related to cardiac autonomic function and cortisol: the TRAILS study

OBJECTIVE

To examine in a nonclinical sample of preadolescents the possibility that somatic and cognitive-affective depressive symptoms are differentially related with the autonomic nervous system (ANS) and the hypothalamic-pituitary-adrenal (HPA) axis. Depression is a well-known risk factor for cardiovascular disease and mortality. Dysregulation of the ANS and the HPA axis have been proposed as underlying mechanisms. Several studies suggest that only a subset of the depression symptoms account for associations with cardiovascular prognosis.

METHODS

Self-reported somatic and cognitive-affective depressive symptoms were examined in relationship to heart rate variability (HRV), spontaneous baroreflex sensitivity (BRS), and the cortisol awakening response (CAR) in 2049 preadolescents (mean age = 11.1 years; 50.7% = girls) from the Tracking Adolescents' Individual Lives Survey (TRAILS).

RESULTS

Physiological measurements were not associated with the overall measure of depressive symptoms. Somatic depressive symptoms were negatively related to HRV and BRS, and positively to the CAR; cognitive-affective depressive symptoms were positively related to HRV and BRS, and negatively to the CAR. Associations with the CAR pertained to boys only.

CONCLUSIONS

Somatic and cognitive-affective depressive symptoms differ in their association with both cardiac autonomic and HPA axis function in preadolescents. Particularly, somatic depression symptoms may mark cardiac risk.

Measuring task-related changes in heart rate variability

Small beat-to-beat differences in heart rate are the result of dynamic control of the cardiovascular system by the sympathetic and parasympathetic nervous systems. Heart rate variability (HRV) has been positively correlated with both mental and physical health. While many studies measure HRV under rest conditions, few have measured HRV during stressful situations. We describe an experimental protocol designed to measure baseline, task, and recovery values of HRV as a function of three different types of stressors. These stressors involve an attention task, a cold pressor test, and a videotaped speech presentation. We found a measurable change in heart rate in participants (n=10) during each task (all p's < 0.05). The relative increase or decrease from pre-task heart rate was predicted by task (one-way ANOVA, p= 0.0001). Spectral analysis of HRV during the attention task revealed consistently decreased measures of both high (68+/-7%, mean+/-S.E.) and low (62+/-13%) frequency HRV components as compared to baseline. HRV spectra for the cold pressor and speech tasks revealed no consistent patterns of increase or decrease from baseline measurements. We also found no correlation in reactivity measures between any of our tasks. These findings suggest that each of the tasks in our experimental design elicits a different type of stress response in an individual. Our experimental approach may prove useful to biobehavioral researchers searching for factors that determine individual differences in responses to stress in daily life.

Depression and anxiety as predictors of heart rate variability after myocardial infarction

BACKGROUND

Reduced heart rate variability (HRV) is a prognostic factor for cardiac mortality. Both depression and anxiety have been associated with increased risk for mortality in cardiac patients. Low HRV may act as an intermediary in this association. The present study examined to what extent depression and anxiety differently predict 24-h HRV indices recorded post-myocardial infarction (MI).

METHOD

Ninety-three patients were recruited during hospitalization for MI and assessed on self-reported symptoms of depression and anxiety. Two months post-MI, patients were assessed on clinical diagnoses of lifetime depressive and anxiety disorder. Adequate 24-h ambulatory electrocardiography data were obtained from 82 patients on average 78 days post-MI.

RESULTS

In unadjusted analyses, lifetime diagnoses of major depressive disorder was predictive of lower SDNN [standard deviation of all normal-to-normal (NN) intervals; beta=-0.26, p=0.022] and SDANN (standard deviation of all 5-min mean NN intervals; beta=0.25, p=0.023), and lifetime anxiety disorder of lower RMSSD (root mean square of successive differences; beta=-0.23, p=0.039). Depression and anxiety symptoms did not significantly predict HRV. After adjustment for age, sex, cardiac history and multi-vessel disease, lifetime depressive disorder was no longer predictive of HRV. Lifetime anxiety disorder predicted reduced high-frequency spectral power (beta=-0.22, p=0.039) and RMSSD (beta=-0.25, p=0.019), even after additional adjustment of anxiety symptoms.

CONCLUSIONS

Clinical anxiety, but not depression, negatively influenced parasympathetic modulation of heart rate in post-MI patients. These findings elucidate the physiological mechanisms underlying anxiety as a risk factor for adverse outcomes, but also raise questions about the potential role of HRV as an intermediary between depression and post-MI prognosis.

Integrating a portable biofeedback device into clinical practice for patients with anxiety disorders: results of a pilot study

This study examined the effectiveness of a portable Respiratory Sinus Arrhythmia (RSA) biofeedback device as an adjunct to CBT in persons with anxiety disorders and other disorders associated with autonomic dysfunction attending outpatient treatment. Participants were 24 individuals attending outpatient cognitive behavioral treatment for a range of anxiety disorders. Participants were assessed over a 3 week period. Outcomes included measures of anxiety (STAI-Y), sleep disturbances (PSQI), anger (STAEI), and subjective questions about the effectiveness of the device as a treatment adjunct. Significant reductions were found for anxiety and anger and for certain sleep variables (e.g. sleep latency). There was a significant dos-effect in that those who were more compliant had significantly greater reductions in most domains including sleep, anger and trait anxiety. Overall, participants found the device more helpful than other relaxation techniques such as mediation, yoga and unassisted breathing techniques but less helpful than exercise. The most frequently endorsed side effects were dizziness (15%) and sleepiness (55%). These preliminary results suggest that portable RSA biofeedback appears to be a promising treatment adjunct for disorders of autonomic arousal and is easily integrated into treatment. Results support the need for further investigation with more rigorous experimental designs.

Specific serotonin reuptake inhibition in major depressive disorder adversely affects novel markers of cardiac risk

There exists a growing body of evidence linking depression with cardiovascular events, although the mechanisms responsible remain unknown. We investigated the role of the autonomic nervous system and inflammation in the link between coronary heart disease and major depressive disorder (MDD), and examined the cardiac risk modification following pharmacological treatment of depression. We measured cardiac baroreflex function, heart rate variability, pulse pressure and high sensitivity C-reactive protein (hsCRP), all of which have an impact on cardiac risk, pre- and post-treatment in 25 patients with MDD, with no history of coronary heart disease, and in 15 healthy subjects. Treatment consisted of selective serotonin reuptake inhibitors for approximately 12 weeks. No significant differences were observed between untreated MDD patients and healthy subjects in blood pressure, heart rate, baroreflex sensitivity or heart rate variability. Pulse pressure and hsCRP, however, were significantly elevated in patients with MDD prior to treatment (p=0.023 and p=0.025, respectively). Moreover, while pharmacotherapy was effective in alleviating depression, surprisingly, each of cardiac baroreflex function, heart rate variability, pulse pressure and hsCRP was modified (p<0.05) in a manner likely to increase cardiac risk. In conclusion, this study demonstrated higher pulse pressure and hsCRP plasma levels in patients with MDD, which might contribute to increased cardiac risk. Following treatment vagal activity was reduced, as indicated by reductions in baroreflex sensitivity and heart rate variability, accompanied by increases in pulse pressure and plasma hsCRP levels. Mechanisms potentially responsible for generating cardiac risk in patients treated with selective serotonin reuptake inhibitors may need to be therapeutically targeted to reduce the incidence of coronary heart disease in this population.

An autonomic flexibility–neurovisceral integration model of anxiety and cardiac vagal tone

Research on heart rate variability (HRV), cardiac vagal tone, and their relationship to anxiety is reviewed in the context of the autonomic flexibility and neurovisceral integration models of adaptive functioning. These perspectives address the qualities of response flexibility and inhibition across multiple levels, incorporating central and autonomic nervous system mechanisms of environmental engagement, as well as principles derived from non-linear dynamics. These models predict reduced HRV and vagal tone in anxiety, and the literature has generally supported this prediction, with exceptions as are noted. State, trait, and clinical expressions of anxiety are considered, along with the clinical, methodological, and theoretical implications of this research. A portrayal of anxiety as a restricted response range across biological and behavioral realms of functioning is drawn from the literature on anxiety and HRV.

Baroreflex mechanisms in major depression

BACKGROUND

Recent studies have shown that depressive disorder is associated with impaired baroreceptor or baroreflex sensitivity, which is proposed to be a predisposing factor for sudden death in patients with manifest cardiac disease. These studies have not evaluated the afferent and efferent components of the cardiac baroreflex loop or other baroreflex mechanisms that regulate target processes (cardiac metabolism and blood pressure variability) related to the impairment. The objective of this study was to gain more insight into autonomic functioning in depressive disorder to more fully examine the potential basis for increased cardiac mortality.

METHODS

The subjects were 28 women and men with unipolar major depression who were taking antidepressant medications and who were in partial remission and free of cardiovascular or other serious disease, and 28 healthy control subjects matched for sex, age, and ethnicity. The two samples were compared for negative affective dispositions (anger expression, hostility, defensiveness, anxiety), spontaneous (closed-loop) baroreflex activity, heart rate, heart rate variability, systolic blood pressure, and heart rate-systolic blood pressure double product under resting conditions.

RESULTS

Depressed patients showed a general disposition to anger suppression coupled with higher hostility and anxiety, and lower defensiveness. The patients showed higher general sympathetic activity (high levels of blood pressure, low-frequency heart rate variability) and lower parasympathetic-related activity (high heart rate and reduced high frequency heart rate variability) with affected cardiac metabolism estimated by the double product. Depressed patients had lower baroreflex sensitivity related to a higher gain of the afferent component of the baroreflex without respective gain adjustment of its efferent component (reflex gain 'de-afferentation'). It was coupled with a compensatory higher number of effective baroreflex reactions (reflex gating 're-afferentation'). Antidepressant agents and depressed mood had additional independent effects on baroreflex sensitivity through the efferent component of the cardiac baroreflex loop.

CONCLUSIONS

The data indicate that different baroreflex components and mechanisms may be impaired in patients with depression and may contribute to their increased cardiac risk.

Respiratory sinus arrhythmia as a function of state anxiety in healthy individuals

Respiratory sinus arrhythmia (RSA) was examined in relation to state and trait anxiety in healthy individuals. Time-frequency analyses of HR-power spectrum in the high frequency region (0.12-0.40 Hz), related to RSA, were examined in 43 women and 39 men. Based on median split, the participants were divided into high and low state and trait anxiety groups. The main result showed that high state anxious individuals had higher RSA-magnitude (HF-power) than low state anxious individuals. The higher RSA-magnitude in the former group was interpreted as reflecting increased attention or vigilance together with motor and behavioural inhibition. No significant effects of trait anxiety or gender were found.

Cardiac vagal control in depression: a critical analysis

Rapidly developing research has found abnormal cardiac vagal control (CVC) in several physical and mental health conditions. CVC findings in depression are mixed, and the degree to which CVC is compromised in depression is unclear. A meta-analysis of 13 rigorous cross-sectional studies reveals that a diagnosis of depression exerts a small-to-medium effect size on CVC, and explains only about 2% of the overall variance in CVC. More robust data may emerge from alternative approaches to the depression-CVC relationship, such as the use of CVC to predict the course of the disorder. Despite the vigor of recent work on CVC and depression, overall findings are suggestive rather than conclusive. Methodological desiderata and priorities for future research are discussed, including the need to clarify the etiological significance of CVC.

Implementation and interpretation of respiratory sinus arrhythmia measures in psychosomatic medicine: practice against better evidence?

Respiratory sinus arrhythmia (RSA) or high-frequency heart rate variability has been widely used as a noninvasive measure of cardiac vagal tone. However, their dependency on both respiration rate and tidal volume is largely ignored. Only a minority of studies published in Psychosomatic Medicine in recent years has implemented precautions for controlling respiration rate in RSA measures, and tidal volume effects were only rarely addressed. We discuss methodologic issues related to respiratory control methods and present data that demonstrate that both respiration rate and tidal volume contribute substantially to the within-individual RSA variance under conditions of variable breathing, with tidal volume contributing up to one third beyond respiration rate. Finally, we outline a respiratory control method for the time-domain index of RSA and review research pertaining to its reliability, validity, and experimental application.

Dysfunctional baroreflex regulation of sympathetic nerve activity in remitted patients with panic disorder. A new methodological approach

BACKGROUND

Many researchers have studied the abnormalities of autonomic nervous system (ANS) such as decreased heart rate variability, which is a risk factor for sudden cardiac death, in patients with panic disorder (PD). However, no consistent abnormality has been uncovered to date. One of the reasons for this controversy may be due to the fact that most of these conventional studies have analyzed each physiological variable independent of other indices. We examined the ANS in PD patients using a new method which can more directly investigate the function of the baroreflex by examining the relation between the blood pressure (BP) and heart rate (HR).

METHODS

During rest and audiovisual stimulation (AS) as mental stress such as being exposed to video imaginary of experiences such as driving motor vehicles, cardiovascular parameters, HR and BP were consecutively measured in 13 remitted PD patients and twenty aged and gender-matched normal controls (NC). In this study, to assess the cardiovascular ANS function (baroreflex) in PD we used the power spectrum analysis as usual and the mean of lag time (tau) between the Mayer wave components, which was closely related to sympathetic nerve activity of vasomotor, of HR and BP variability as a new trial.

RESULTS

The PD patients and NC did not differ with regard to the power spectrum analysis of the heart rate. We found that tau in the PD group was significantly shorter than that in the NC both before and after AS, especially before.

CONCLUSIONS

These findings suggest that remitted PD patients may have a dysfunctional baroreflex regulation of sympathetic nerve activity.

Social support and religiosity as coping strategies for anxiety in hospitalized cardiac patients

BACKGROUND

Prospective studies have demonstrated that anxiety is associated with an increased risk of mortality and sudden cardiac death. There is therefore a need to understand what factors contribute to anxiety in patients with coronary heart disease (CHD).

PURPOSE

This study examined whether social support and religiosity are individually or jointly associated with lower anxiety in cardiac patients.

METHODS

Anxiety, perceived social support, and religiosity were assessed in 228 (71% male, 29% female) hospitalized CHD patients aged 62 +- 11 years.

RESULTS

Higher levels of social support were related to lower levels of state and trait anxiety (state anxiety, r = -.26, p < .01; trait anxiety, r = -.30, p < .01;). Religiosity was related to lower state anxiety (r = -.27, p < .01) but only modestly related to lower trait anxiety (trait anxiety, r = -.18, p < .01). The relationship between religiosity and trait anxiety was no longer significant after controlling for social support (p = .26).

CONCLUSIONS

These findings suggest that religiosity and social support provide a buffer against anxiety in CHD patients and that higher levels of social support may account for the relationship between religiosity and trait anxiety. These findings underscore the importance of social support and religiosity as buffers against distress, with possible implications for prognosis in a patient group where high levels of anxiety appear to confer increased risk of mortality.

Pseudocholinesterase activity increases and heart rate variability decreases with preoperative anxiety

BACKGROUND AND OBJECTIVE

The objective of this study was to determine the influence of preoperative anxiety on the activity of plasma cholinesterase and heart rate (HR) variability.

METHODS

A total of 50 subjects were studied, 25 male patients one day preoperatively and 25 male volunteers without surgical intervention as a control group. Blood samples were taken to determine plasma cholinesterase activity. HR variability was recorded for a period of 256 beat-to-beat intervals and analysed by frequency domain analysis into very low frequency (VLF: 0.02-0.04 Hz), low frequency (LF: 0.04-0.15 Hz) and high frequency (HF: 0.15-0.4 Hz). LF/HF ratio and total power over the 0.02-0.4 Hz range were calculated. Anxiety levels were assessed using the hospital anxiety and depression scale, the self-rating anxiety scale and a visual analogue scale.

RESULTS

The patient group had significantly higher anxiety scores. Plasma cholinesterase activity was significantly higher in patients vs. controls (6646 vs. 5324 units L(-1)). Total power, LF and HF were significantly lower in the patients (1489 vs. 2581 ms2; 656 vs. 1186 ms2; 491 vs. 964 ms2, respectively).

CONCLUSIONS

Preoperative anxiety increases plasma cholinesterase activity and decreases HR variability.

Linear and nonlinear measures of blood pressure variability: increased chaos of blood pressure time series in patients with panic disorder

Arterial blood pressure (BP) variability increases progressively with the development of hypertension and an increase in BP variability is associated with end organ damage and cardiovascular morbidity. On the other hand, a decrease in heart rate (HR) variability is associated with significant cardiovascular mortality. There is a strong association between cardiovascular mortality and anxiety. Several previous studies have shown decreased HR variability in patients with anxiety. In this study, we investigated beat-to-beat variability of systolic and diastolic BP (SBP and DBP) in normal controls and patients with panic disorder during normal breathing and controlled breathing at 12, and 20 breaths per minute using linear as well as nonlinear techniques. Finger BP signal was obtained noninvasively using Finapres. Standing SBPvi and DBP BPvi (log value of BP variance corrected for mean BP divided by HR variance corrected for mean HR) were significantly higher in patients compared to controls. Largest Lyapunov exponent (LLE) of SBP and DBP, a measure of chaos, was significantly higher in patients in supine as well as standing postures. The ratios of LLE (SBP/HR) and LLE (DBP/HR) were also significantly higher (P<.001) in patients compared to controls. These findings further suggest dissociation between HR and BP variability and a possible relative increase in sympathetic function in anxiety. This increase in BP variability may partly explain the increase in cardiovascular mortality in this group of patients.

Anxiety and hostility are associated with reduced baroreflex sensitivity and increased beat-to-beat blood pressure variability

OBJECTIVE

The purpose of this study was to determine whether psychological factors are associated with heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) among healthy middle-aged men and women.

METHODS

A population-based sample of 71 men and 79 women (35-64 years of age) was studied. Five-minute supine recordings of ECG and beat-to-beat photoplethysmographic finger systolic arterial pressure and diastolic arterial pressure were obtained during paced breathing. Power spectra were computed using a fast Fourier transform for low-frequency (0.04-0.15 Hz) and high-frequency (0.15-0.40 Hz) powers. BRS was calculated by cross-spectral analysis of R-R interval and systolic arterial pressure variabilities. Psychological factors were evaluated by three self-report questionnaires: the Brief Symptom Inventory, the shortened version of the Spielberger State-Trait Anger Expression Inventory, and the Toronto Alexithymia Scale.

RESULTS

Psychological factors were not related to HRV. Anxiety was associated with decreased BRS (p = 0.001) and higher low-frequency (p = 0.002) power of systolic arterial pressure variability. These associations were independent of age, gender, other psychological factors, heart rate, and systolic and diastolic blood pressures. Hostility was an independent correlate of increased low-frequency power of diastolic arterial pressure (p = 0.001) and increased high-frequency power of systolic arterial pressure (p = 0.033) variability.

CONCLUSIONS

Anxiety and hostility are related to reduced BRS and increased low-frequency power of BPV. Reduced BRS reflects decreased parasympathetic outflow to the heart and may increase BPV through an increased sympathetic predominance.

Comorbidity of depression and anxiety in the elderly

Elderly patients with depression commonly suffer from concurrent symptoms of anxiety or comorbid anxiety disorders. Such comorbidity is associated with a more severe presentation of depressive illness, including greater suicidality. Additionally, most antidepressant treatment studies of elderly individuals with depression have found poorer treatment outcomes in those with comorbid anxiety, for example, delayed or diminished response and increased likelihood of dropout from treatment. In terms of treatment of anxious depression, there is evidence that tricyclic antidepressants and serotonin reuptake inhibitors are not different from each other in terms of efficacy or tolerability. Rather than the specific choice of antidepressant medication, it appears that quality of clinical management has the greatest impact on likelihood of remission in anxious depressed elderly individuals. Co-prescription of benzodiazepines is sometimes warranted for severe anxiety, but increases the risk of cognitive or motor impairment. Psychotherapy, including cognitive-behavioral therapy and interpersonal therapy, which are efficacious for late-life depression in general, should also be considered for treatment alone or in combination with appropriate medication. Future research areas are also addressed in this paper.

Sympathetic and cardiac baroreflex function in panic disorder

BACKGROUND

Recent reports have demonstrated increased cardiac risk, and an association with essential hypertension in patients with panic disorder. The cause is not known, but possibly involves sympathetic nervous activation. In this study, we evaluated the arterial baroreflex control of vascular sympathetic nervous outflow and cardiac baroreflex function in panic disorder patients.

METHODS AND RESULTS

We studied nine patients suffering from panic disorder and ten healthy subjects. Microneurographic recording of muscle sympathetic nerve activity (MSNA) was made with simultaneous recording of blood pressure (BP) and electrocardiogram (ECG). The relationship between MSNA and spontaneous diastolic BP (DBP) changes was assessed at rest and was defined as the arterial baroreflex control of MSNA. Cardiac baroreflex function was assessed using the sequence method. Anxiety was assessed using Spielberger's anxiety state and trait inventory. The slopes of the relationship between MSNA and DBP were more negative (steeper) in the panic disorder group compared with the control subjects (-5.97 +/- 0.45 versus -3.06 +/- 0.43 bursts/100 heart beats per mmHg, P < 0.001). Panic disorder patients had significantly higher state and trait anxiety scores. The slope of the relationship between MSNA and diastolic BP was significantly related to the trait anxiety of the subjects. There was no difference between the cardiac baroreflex sensitivity between the two groups.

CONCLUSION

Patients with panic disorder exhibit enhanced reflex gain of the arterial baroreflex control of MSNA but no change in the cardiac baroreflex. While any clinical significance this observation might have in relation to increased cardiac risk in panic disorder, or to concordance with essential hypertension, remains to be elucidated, increased reactivity of vasoconstricting sympathetic nerves may be a trait characteristic in this cohort.