Cardiac autonomic control buffers blood pressure variability responses to challenge: a psychophysiologic model of coronary artery disease

Towards understanding the complexity of cardiovascular oscillations: Insights from information theory

Cardiovascular complexity is a feature of healthy physiological regulation, which stems from the simultaneous activity of several cardiovascular reflexes and other non-reflex physiological mechanisms. It is manifested in the rich dynamics characterizing the spontaneous heart rate and blood pressure variability (HRV and BPV). The present study faces the challenge of disclosing the origin of short-term HRV and BPV from the statistical perspective offered by information theory. To dissect the physiological mechanisms giving rise to cardiovascular complexity in different conditions, measures of predictive information, information storage, information transfer and information modification were applied to the beat-to-beat variability of heart period (HP), systolic arterial pressure (SAP) and respiratory volume signal recorded non-invasively in 61 healthy young subjects at supine rest and during head-up tilt (HUT) and mental arithmetics (MA). Information decomposition enabled to assess simultaneously several expected and newly inferred physiological phenomena, including: (i) the decreased complexity of HP during HUT and the increased complexity of SAP during MA; (ii) the suppressed cardiorespiratory information transfer, related to weakened respiratory sinus arrhythmia, under both challenges; (iii) the altered balance of the information transferred along the two arms of the cardiovascular loop during HUT, with larger baroreflex involvement and smaller feedforward mechanical effects; and (iv) an increased importance of direct respiratory effects on SAP during HUT, and on both HP and SAP during MA. We demonstrate that a decomposition of the information contained in cardiovascular oscillations can reveal subtle changes in system dynamics and improve our understanding of the complexity changes during physiological challenges.

Heart Rate Variability and Cognitive Function In Middle-Age Adults: The Coronary Artery Risk Development in Young Adults

BACKGROUND

Low heart rate variability (HRV), a marker of cardiac autonomic dysfunction, has been associated with major risk factors of cognitive impairment. Yet, the direct association of HRV with cognitive function remains relatively unexplored, particularly in midlife.

METHODS

In 2005, 2 measures of short-term HRV, the SD of normal-to-normal intervals (SDNN) and the root mean square of successive differences (RMSSD), were calculated for participants of the Coronary Artery Risk Development in Young Adults study, and then categorized into quartiles. Five years later, 3 cognitive tests were administered for verbal memory ("Rey Auditory-Verbal Learning Test", RAVLT, range 0-15), processing speed ("Digit Symbol Substitution Test", DSST, range 0-133), and executive function ("Stroop interference").

RESULTS

Two thousand one hundred and eighteen participants (57.7% female, 42.2% Black) with a mean baseline age of 45.3 years were included in this analysis. In demographic-adjusted models, compared to participants with quartile 1 SDNN (lowest quartile), participants in the upper quartiles of SDNN scored better on the DSST (quartile 4: β = 1.83 points better, P = 0.03; and quartile 3: β = 1.95 points better, P = 0.03) and on the stroop (quartile 3: β = 1.19 points better, P < 0.05; and quartile2: β = 1.44 points better, P = 0.02). After adjusting for behavioral and cardiovascular risk factors, higher quartile SDNN remained significantly associated with better stroop score (quartile 3: β = 1.21 points better, P = 0.04; and quartile 2: β = 1.72 points better, P < 0.01) but not with DSST. There was no association between quartile of RMSSD and cognitive function, from fully adjusted models.

CONCLUSIONS

Our findings suggest that higher quartile SDDN is associated with better executive function in midlife, above, and beyond cardiovascular risk factors.

The association of posttraumatic stress disorder and chronic medical conditions by ethnicity

Our study extends the literature on associations between posttraumatic stress disorder (PTSD) and chronic medical conditions by assessing differences in the magnitude of these relations by ethnicity. We examined group differences in the magnitude of the relation between PTSD and chronic medical conditions (cardiovascular disease [CVD], hypertension, obesity, diabetes). We obtained data from Latino (n = 3,224) and non-Latino white (n = 4,180) respondents from the Collaborative Psychiatric Epidemiology Surveys. Logistic regression models were constructed to test for the modification of the effect of PTSD on chronic medical conditions by ethnicity, and then by nativity. Unadjusted models revealed significant interactions between Latino ethnicity and PTSD for odds of diabetes (OR = 2.18 [Latino] v. 0.81 [non-Latino white]), CVD (OR = 3.23 [Latino] v. 1.28 [non-Latino white]), and hypertension (OR = 1.61 [Latino] v. 0.98 [non-Latino white]). Among U.S.-born Latinos, we found a significant interaction between ethnicity and PTSD for odds of CVD (OR = 4.18 [Latino] v. 1.28 [non-Latino white]) and diabetes (OR = 2.27 [Latino] v. 0.81 [non-Latino white]). These findings attenuated in adjusted models with the exception of differences in PTSD and odds of diabetes among Latinos (including aggregated group & U.S.-born) compared to non-Latino whites. Our findings support the need for further research on the complex relations between PTSD and chronic conditions, including the investigation of conditional risk by Latino sub-groups.

Trauma and Autonomic Dysregulation: Episodic-Versus Systemic-Negative Affect Underlying Cardiovascular Risk in Posttraumatic Stress Disorder

OBJECTIVE

Posttraumatic stress disorder (PTSD) has been linked to elevated heart rate (HR) and reduced heart rate variability (HRV) in cross-sectional research. Recent evidence suggests that this link may be driven by individual differences in autonomic arousal associated with momentary negative affect (NA). Using ecological momentary assessment (EMA) of NA and minute-to-minute HR/HRV monitoring, we examined whether NA-related HR/HRV mediated the association of PTSD symptom severity with 24-hour HRV and endothelial functioning.

METHODS

One hundred ninety-seven young adults (18-39 years), 93 with PTSD, underwent 1 day of Holter monitoring while concurrently reporting NA levels via EMA. Two noninvasive measures of endothelial functioning-flow-mediated dilation and hyperemic flow-were also collected. Multilevel modeling was used to assess the associations of momentary NA with HR and low- and high-frequency HRV during the 5-minute intervals after each EMA reading. Latent variable modeling was then used to determine whether individual differences in these associations mediated the association of PTSD symptom severity with 24-hour HRV, flow-mediated dilation, and hyperemic flow.

RESULTS

PTSD symptom severity was positively associated with NA-related autonomic arousal (β = .21, p < .001), which significantly mediated the association of PTSD symptom severity with 24-hour HRV and hyperemic flow, accounting for 62% and 34% of their associations, respectively, while overshadowing the influence of smoking, lifetime alcohol dependence, sleep duration, mean NA, and episodes of acute NA.

CONCLUSIONS

Results suggest that NA-related autonomic arousal is both a primary factor driving cardiovascular risk in PTSD and a potential point of intervention.

Coping, schemas, and cardiovascular risks - study protocol

The aim of this article is to describe the protocol of a trial focusing on the psychological, anthropometric, cardiac, and psychophysiological factors contributing to increased risk of cardiovascular diseases (CVDs). As background, the article provides a short overview of research literature linking personal traits, maladaptive schemas, and coping styles with CVDs through reactivity of the autonomic nervous system.

Which psychological, psychophysiological, and anthropometric factors are connected with life events, depression, and quality of life in patients with cardiovascular disease

OBJECTIVE

The aim of the study was to determine psychological, psychophysiological, and anthropometric factors connected with life events, level of depression, and quality of life in people at risk for cardiovascular disease and healthy controls.

METHODS

This is a cross-sectional study involving arterial hypertension patients and healthy controls. There were several measurements including physical, anthropological, cardiovascular, and psychophysiological measurements and administration of questionnaires.

RESULTS

A total of 99 participants were recruited for this study, 54 healthy controls (mean age: 35.59±13.39 years) and 45 patients with cardiovascular disease (CVD) (mean age: 46.33±12.39 years). The healthy controls and the patients with CVD significantly differed in the mean total score of life events, level of depression, quality of life score, temperature, blood pressure (BP), pulse transit time, heart rate, high-frequency total power, heart rate variability total power, waist-to-height ratio (WHtR), body fat percentage, fat control, pulse wave velocity, and augmentation index. In healthy subjects, the total score of the life events was not correlated with any cardiovascular or anthropometric factor. A score of depression significantly correlated with the WHtR, augmentation index, body fat percentage, and fat control. The quality of life - visual scale correlated with the body temperature, BP, and percentage of body fat. In the group of the patients with CVD, the score of the life events did not correlate with any measured cardiovascular or anthropometric factor. The level of depression correlated with the augmentation index. The quality of life - visual scale significantly correlated with body temperature, WHtR, and fat control.

CONCLUSION

The patients with CVD reported higher scores of life events, worse quality of life, and a greater level of depressive symptoms than healthy controls. In healthy controls, a higher mean total score of life events significantly negatively correlated with high-frequency total power, and the degree of depression correlated with being overweight. In patients with CVD, a score of depression was linked to being overweight.

[Septoplasty and tonsillectomy: acute stress response as a measure of effectiveness of local anesthetics]

AIM

To compare the effectiveness of lidocaine and articaineused as local anesthetics in septoplasty and tonsillectomy based on the physiological stress response.

PATIENTS AND METHODS

The study included 125 patients with nasal septum deviation (NSD) and chronic tonsillitis (CT). The patients presenting with NSD were divided into two groups. Those comprising group 1A (n=32) were treated with a 2% lidocaine solution for local infiltration analgesia (LIA), the patients of group 1B (n=30) were given 2%articaine as LIA. Group 2A contained 32 patients with CT treated with lidocaine, group 2B consisted of 31 patients given articaine. In all the patients, the overall heart rate variability (HRV) including its high, low, and very low components was measured.

RESULTS

Evaluation of HRV revealed a certain degree of disadaptation in the patients of groups 1B and 2A. High dispersion of SDANN, SDNN index, andrMSSD in group 1Bas well as SDANN values in group 2A indicates the sympathetic/parasympathetic imbalance. The high-frequency component was augmented in group 2B which suggested the prevalence of parasympathetic tone, but its high dispersion was just aswell indicative of disadaptation.

CONCLUSION

Local analgesia with articaine during septoplasty leads tosympathetic/parasympathetic imbalance during the early postoperative period. Lidocaine analgesia for tonsillectomy does not prevent disadaptation induced by surgical stress.

Stress-induced remodeling of hippocampal CA3 pyramidal neurons

The discovery of steroid hormone receptors in brain regions that mediate virtually every aspect of brain function has broadened the definition of 'neuroendocrinology' to include the reciprocal communication between the brain and the body via hormonal and neural pathways. The brain is the central organ of stress and adaptation to stress because it perceives and determines what is threatening, as well as determining the behavioral and physiological responses to the stressor. The adult and developing brain possess remarkable structural and functional plasticity in response to stress, including neurogenesis leading to neuronal replacement, dendritic remodeling, and synapse turnover. Stress causes an imbalance of neural circuitry subserving cognition, decision-making, anxiety and mood that can alter expression of those behaviors and behavioral states. The two Brain Research papers noted in this review played an important role in triggering these advances. This article is part of a Special Issue entitled SI:50th Anniversary Issue.

Self-Esteem and the Acute Effect of Anxiety on Ambulatory Blood Pressure

OBJECTIVES

Recent research suggests that self-esteem may be associated with improved parasympathetic nervous system functioning. This study tested whether high self-esteem is associated with decreased ambulatory systolic blood pressure (ASBP) reactivity to anxiety in healthy adults during the waking hours of a normal day.

METHODS

Each of 858 participants completed a short version of the Rosenberg Self-Esteem Scale and then wore an ABP monitor that took two blood pressure readings per hour for 24 hours. Immediately after each blood pressure reading, participants completed an electronic diary report that included an anxiety rating on a 100-point visual analog scale. Using multilevel models, we assessed the association of momentary anxiety, high trait self-esteem, and their interaction on momentary ASBP, with adjustment for age, sex, race, ethnicity, and body mass index. Sensitivity analyses were conducted examining psychological factors associated with self-esteem: sense of mastery, optimism, social support, and depressive symptoms.

RESULTS

On average, a 1-point increase in cube root-transformed anxiety was associated with a 0.80-mm Hg (standard error = 0.09, p < .001) increase in ASBP, and the interaction of high self-esteem and momentary anxiety was significant, such that this effect was 0.48 (standard error = 0.20, p = .015) less in individuals with high self-esteem compared with all others. Results for self-esteem remained significant when adjusting for sex and psychological factors.

CONCLUSIONS

Momentary increases in anxiety are associated with acute increases in ASBP, and high self-esteem buffers the effect of momentary anxiety on blood pressure. Thus, high self-esteem may confer cardiovascular benefit by reducing the acute effects of anxiety on systolic blood pressure.

60 YEARS OF NEUROENDOCRINOLOGY: Redefining neuroendocrinology: stress, sex and cognitive and emotional regulation

The discovery of steroid hormone receptors in brain regions that mediate every aspect of brain function has broadened the definition of 'neuroendocrinology' to include the reciprocal communication between the brain and the body via hormonal and neural pathways. The brain is the central organ of stress and adaptation to stress because it perceives and determines what is threatening, as well as the behavioral and physiological responses to the stressor. The adult and developing brain possess remarkable structural and functional plasticity in response to stress, including neuronal replacement, dendritic remodeling, and synapse turnover. Stress causes an imbalance of neural circuitry subserving cognition, decision-making, anxiety and mood that can alter expression of those behaviors and behavioral states. This imbalance, in turn, affects systemic physiology via neuroendocrine, autonomic, immune and metabolic mediators. In the short term, as for increased fearful vigilance and anxiety in a threatening environment, these changes may be adaptive. But, if the danger passes and the behavioral state persists along with the changes in neural circuitry, such maladaptation may need intervention with a combination of pharmacological and behavioral therapies, as is the case for chronic anxiety and depression. There are important sex differences in the brain responses to stressors that are in urgent need of further exploration. Moreover, adverse early-life experience, interacting with alleles of certain genes, produce lasting effects on brain and body over the life-course via epigenetic mechanisms. While prevention is most important, the plasticity of the brain gives hope for therapies that take into consideration brain-body interactions.

Posttraumatic stress disorder and incident heart failure among a community-based sample of US veterans

OBJECTIVES

We investigated the association between posttraumatic stress disorder (PTSD) and incident heart failure in a community-based sample of veterans.

METHODS

We examined Veterans Affairs Pacific Islands Health Care System outpatient medical records for 8248 veterans between 2005 and 2012. We used multivariable Cox regression to estimate hazard ratios and 95% confidence intervals for the development of heart failure by PTSD status.

RESULTS

Over a mean follow-up of 7.2 years, veterans with PTSD were at increased risk for developing heart failure (hazard ratio [HR] = 1.47; 95% confidence interval [CI] = 1.13, 1.92) compared with veterans without PTSD after adjustment for age, gender, diabetes, hyperlipidemia, hypertension, body mass index, combat service, and military service period. Additional predictors for heart failure included age (HR = 1.05; 95% CI = 1.03, 1.07), diabetes (HR = 2.54; 95% CI = 2.02, 3.20), hypertension (HR = 1.87; 95% CI = 1.42, 2.46), overweight (HR = 1.72; 95% CI = 1.25, 2.36), obesity (HR = 3.43; 95% CI = 2.50, 4.70), and combat service (HR = 4.99; 95% CI = 1.29, 19.38).

CONCLUSIONS

Ours is the first large-scale longitudinal study to report an association between PTSD and incident heart failure in an outpatient sample of US veterans. Prevention and treatment efforts for heart failure and its associated risk factors should be expanded among US veterans with PTSD.

Orthostatic hypotension in young adults with and without posttraumatic stress disorder

The purpose of this research is (a) to evaluate differences in orthostatic hypotension (OH) among young adults with and without posttraumatic stress disorder (PTSD) and (b) to examine whether group differences may be attributable to behavioral risk factors frequently associated with PTSD. Volunteers and U.S. veterans 18 to 39 years old (N = 222) completed a semistructured interview assessment of PTSD status. Direct measurements were obtained for supine and standing systolic and diastolic blood pressure at study visits, as well as height and weight, from which body mass index (BMI) was calculated. After controlling for use of psychotropic medications, a logistic regression model revealed that PTSD status was positively associated with OH, such that participants with PTSD were at 4.51 greater odds of having OH than control participants. Moreover, this effect was partially mediated by lifetime alcohol dependence (bootstrapped 95% confidence interval [-0.83, -0.20]). Overall, PTSD may pose a significant risk for OH among younger adults. In the present sample, this relationship was primarily driven by the disproportionately high history of alcohol dependence among individuals with PTSD. These results suggest that traditional therapy for PTSD should be coupled with treatment for alcohol dependency, when applicable, to reap both psychological and physiological benefits.

Posttraumatic stress, heart rate variability, and the mediating role of behavioral health risks

OBJECTIVE

Posttraumatic stress disorder (PTSD) has been linked to reduced heart rate variability (HRV), which is in turn a risk factor for cardiovascular disease and death. Although hyperarousal and anxiety are thought to underlie this association, behavioral health risks, including smoking, alcohol dependence, obesity, and sleep disturbance, represent potential mechanisms linking PTSD and HRV.

METHODS

To test this hypothesis, short-term laboratory-based and 24-hour ambulatory measures of HRV were collected from 227 young adults (18-39 years), 107 of whom were diagnosed as having PTSD. Latent variable modeling was used to assess the relationship of PTSD symptoms with HRV along with potential behavioral health mediators.

RESULTS

PTSD symptoms were associated with reduced HRV (β = -0.21, p = .002). However, this association was reduced in models that adjusted for cigarette consumption and history of alcohol dependence and was rendered nonsignificant in a model adjusting for sleep disturbance. Independent mediation effects were deemed significant via bootstrapping analysis. Together, the three behavioral health factors (cigarette consumption, history of alcohol dependence, and sleep disturbance) accounted for 94% of the shared variance between PTSD symptoms and HRV. Abdominal obesity was not a significant mediator.

CONCLUSIONS

These results indicate that behavioral factors-specifically smoking, alcohol overuse, and sleep disturbance-mediate the association between PTSD and HRV-based indices of autonomic nervous system dysregulation. Benefits from psychiatric and psychological interventions in PTSD may therefore be enhanced by including modification of health behaviors.

Reduced heart rate variability is associated with worse cognitive performance in elderly Mexican Americans

Reduced heart rate variability is a strong predictor of cardiovascular risk factors, cardiovascular events, and mortality and thus may be associated with cognitive neurodegeneration. Yet, this has been relatively unexplored, particularly in minority populations with high cardiovascular burden. We used data from the Sacramento Area Latino Study on Aging to examine the cross-sectional association of reduced heart rate variability with cognitive function among elderly Mexican Americans. A total of 869 participants (mean age, 75 years; 59% women) had their 6-minute heart rate variability measured using an ECG monitor and respiration pacer in response to deep breathing. We used the mean circular resultant, known as R bar, as a measure of heart rate variability and categorized it into quartiles (Q1 to Q4 of R bar: reduced to high heart rate variability). Cognitive function was assessed using the modified Mini-Mental State Examination, a 100-point test of global cognitive function, and the Spanish and English verbal learning test, a 15-point test of verbal memory recall. In fully adjusted linear regression models, participants in quartile 1 had a 4-point lower modified Mini-Mental State Examination score (P<0.01), those in quartile 2 had a 2-point lower score (P=0.04), and those in quartile 3 had a 1-point lower score (P=0.35) compared with those in the highest quartile of R bar. Reduced R bar was not associated with verbal memory. Our results suggest that reduced heart rate variability is associated with worse performance on the test of global cognitive function, above and beyond traditional cardiovascular risk factors.

Effect of physical activity on heart rate variability and carotid intima-media thickness in older people

We investigated the effect of physical activity on heart rate variability (HRV) and carotid intima-media thickness (IMT) in elderly subjects and the relationship between HRV and IMT. Thirty-two elderly sedentary subjects and 32 age-matched endurance athletes underwent ultrasonography of the carotid wall for measuring IMT, and 24-h ECG monitoring for measuring HRV. Elderly athletes had evidence of increased vagal activity in the time (SDANN, rMSSD, and pNN50; p < 0.01) and frequency domain (HF and LF/HF ratio, p < 0.01) with respect to sedentary subjects. Moreover, athletes showed lower IMT than control subjects (p < 0.01). In the whole population SDNN was inversely related to IMT, respectively (r = -0.60 and r = -0.58, p < 0.0001), while LF/HF ratio related positively to IMT. In conclusion, this study demonstrated that in aging HRV is negatively associated with IMT, a putative index of atherosclerosis, confirming cardiac autonomic neuropathy as part of the pathophysiological pathway for atherosclerosis. It confirms that the regular physical activity represents a valuable strategy to counter age-related impairments of cardiac autonomic activity and artery structural changes.

Autonomic dysfunction in type 2 diabetes mellitus with and without vascular dementia

INTRODUCTION

Autonomic dysfunction has been implicated in sudden cardiac death and cognitive impairment in diabetes.

OBJECTIVES

Objectives of the study were to examine the associations between vascular, metabolic risk factors, autonomic and cognitive function in patients with diabetes mellitus.

METHOD

We investigate autonomic function in 45 participants with type 2 diabetes and in 23 age related normal subjects, using Ewing's tests and power spectral analysis of heart rate variability. Mini Mental State Examination and Hachinski's ischemic scale were used to identify vascular dementia. Only 11 patients were diagnosed with vascular dementia.

RESULTS

The glycosylated haemoglobin, triglycerides, and systolic blood pressure had much larger values in vascular dementia patients compared to the controls. The averages of results obtained in heart rate deep-breathing, Valsalva ratio and lying-to-standing tests for vascular dementia patients are statistically lower than the averages for controls. Vascular dementia patients had a greater fall in blood pressure on standing (p<0.001) and reduced blood pressure responses to isometric exercise (p<0.001) in comparison with controls. Also they had an increase in the mean heart rate at rest (p<0.05), a decrease in time domain parameters of heart rate variability (p<0.001), and an increase in the low/high frequency component ratio (p<0.001) indicating a vagal-sympathetic dysfunction.

CONCLUSIONS

Using standard cardiovascular reflex tests and analysis of heart rate variability we demonstrated an impairment of the autonomic nervous system in vascular dementia patients with marked parasympathetic dysfunction and sympathetic predominance.

Combined effect of depressive symptoms and hostility on autonomic nervous system function

Depression and hostility have been separately related to indicators of sympathetic hyperactivation and parasympathetic hypoactivation. We examined the associations of depressive symptoms, hostility, and their interaction with pre-ejection period (PEP) and high frequency heart rate variability (HRV), specific indices of sympathetic and parasympathetic cardiac control, respectively. Healthy, young adults (N=120) completed questionnaires assessing depressive symptoms and hostility and underwent autonomic testing. Although main effects were not observed, a depressive symptoms×hostility interaction was detected for PEP (β=.25, p=.01). Simple slope analyses revealed that hostility was negatively related to PEP among individuals with low depressive symptoms but was not associated with PEP among those with mild-to-moderate depressive symptoms. No interaction effect was detected for high frequency HRV. Our findings suggest that depressive symptoms may moderate the link between hostility and sympathetic activation such that hostility is accompanied by sympathetic hyperactivation only when depressive symptoms are minimal.

Exposure to smoking cues: cardiovascular and autonomic effects

Laboratory exposures to smoking cues have been shown to reliably induce self-reported cigarette cravings among smokers, a model of environmentally triggered urges to smoke that can contribute to poorer cessation success. Several studies have also demonstrated that cue exposures give rise to changes in heart rate and blood pressure. Few studies, however, have investigated possible cue effects on heart rate and blood pressure variability (HRV and BPV). Particularly intriguing in this regard are cardiac oscillations in the low (i.e., 0.04-0.15 Hz), and high (i.e., 0.15-0.50 Hz) frequency range, which are thought to reflect components of autonomic control and response to environmental challenges. A closer examination of cardiovascular reactivity may thus help characterize the autonomic response to smoking cue exposure. To that end, an experimental study was conducted in which nicotine dependent daily smokers (n=98) were exposed to guided imagery of neutral and smoking situations, while continuous, noninvasive, beat-to-beat cardiovascular data were collected. Consistent with previous research, the findings revealed significant increases in both systolic and diastolic blood pressure during smoking imagery, relative to neutral imagery. In addition, power spectral density analyses of heart rate and blood pressure variability revealed elevated HRV and BPV in both the low- and high-frequency ranges during the smoking imagery. The results suggest the presence of an autonomic component to smoking cue reactivity, and also raise the possibility of long-term negative cardiac consequences for smokers who ubiquitously encounter cues in their daily environments.

A topographical map of the causal network of mechanisms underlying the relationship between major depressive disorder and coronary heart disease

OBJECTIVE

Major depressive disorder (MDD) and coronary heart disease (CHD) are both clinically important public health problems. Depression is linked with a higher incidence of ischaemic cardiac events and MDD is more prevalent in patients with CHD. No single comprehensive model has yet described the causal mechanisms linking MDD to CHD. Several key mechanisms have been put forward, comprising behavioural mechanisms, genetic mechanisms, dysregulation of immune mechanisms, coagulation abnormalities and vascular endothelial dysfunction, polyunsaturated omega-3 free fatty acid deficiency, and autonomic mechanisms. It has been suggested that these mechanisms form a network, which links MDD and CHD. The aim of this review is to examine the causal mechanisms underlying the relationship between MDD and CHD, with the aim of constructing a topological map of the causal network which describes the relationship between MDD and CHD.

METHODS

The search term 'depression and heart disease' was entered into an electronic multiple database search engine. Abstracts were screened for relevance and individually selected articles were collated.

RESULTS

This review introduces the first topological map of the causal network which describes the relationship between MDD and CHD.

CONCLUSIONS

Viewing the causal pathways as an interdependent network presents a new paradigm in this field and provides fertile ground for further research. The causal network can be studied using the methodology of systems biology, which is briefly introduced. Future research should focus on the creation of a more comprehensive topological map of the causal network and the quantification of the activity between each node of the causal network.

Interactions between systemic hemodynamics and cerebral blood flow during attentional processing

The study explored interactions between systemic hemodynamics and cerebral blood flow during attentional processing. Using transcranial Doppler sonography, blood flow velocities in the middle cerebral arteries (MCA) of both hemispheres were recorded while 50 subjects performed a cued reaction time task. Finger arterial pressure and heart rate were also continuously monitored. Doppler sonography revealed a right dominant blood flow response. The extent of the increase measured in second two of the interstimulus interval showed a clear positive association with reaction speed. Task-related changes in blood pressure and heart rate proved predictive of changes in MCA flow velocities in limited time windows of the response. Besides an association between cerebral blood flow and attentional performance, the results suggest a marked impact of systemic hemodynamics on the blood flow response. All observed interactions are highly dynamic in time.

Autonomic cardiovascular control and responses to experimental pain stimulation in fibromyalgia syndrome

OBJECTIVE

This study involves a comprehensive investigation of autonomic cardiovascular regulation in fibromyalgia syndrome (FMS) at rest and during painful stimulation and its association with pain indices.

METHODS

In 35 patients and 29 healthy controls, electrocardiography, impedance cardiography, and finger continuous blood pressure measurements were conducted. For the purpose of experimental pain induction, a cold pressor test was applied.

RESULTS

FMS patients showed lower pain threshold and tolerance, as well as higher ratings of pain intensity and unpleasantness on visual analogue scales. Resting stroke volume, myocardial contractility, R-R interval, heart rate variability, and sensitivity of the cardiac baroreflex were reduced in the patients, and increases in stroke volume and myocardial contractility during cold pressor stimulation were less pronounced. In the whole sample as well as in the FMS group, baroreflex sensitivity was inversely associated with subjective pain intensity, and a higher number of baroreflex operations per unit of time predicted higher pain tolerance.

CONCLUSIONS

The data suggest impaired autonomic cardiovascular regulation in FMS in terms of reduced sympathetic and parasympathetic influences, as well as blunted sympathetic reactivity to acute stress. The association between baroreflex function and pain experience reflects the pain inhibition mediated by the baroreceptor system. Given the reduced baroreflex sensitivity in FMS, one may assume deficient ascending pain inhibition arising from the cardiovascular system, which may contribute to the exaggerated pain sensitivity of FMS.

Posttraumatic stress disorder, cardiovascular, and metabolic disease: a review of the evidence

BACKGROUND

Posttraumatic stress disorder (PTSD) is a significant risk factor for cardiovascular and metabolic disease.

PURPOSE

The purpose of the current review is to evaluate the evidence suggesting that PTSD increases cardiovascular and metabolic risk factors, and to identify possible biomarkers and psychosocial characteristics and behavioral variables that are associated with these outcomes.

METHODS

A systematic literature search in the period of 2002-2009 for PTSD, cardiovascular disease, and metabolic disease was conducted.

RESULTS

The literature search yielded 78 studies on PTSD and cardiovascular/metabolic disease and biomarkers.

CONCLUSIONS

Although the available literature suggests an association of PTSD with cardiovascular disease and biomarkers, further research must consider potential confounds, incorporate longitudinal designs, and conduct careful PTSD assessments in diverse samples to address gaps in the research literature. Research on metabolic disease and biomarkers suggests an association with PTSD, but has not progressed as far as the cardiovascular research.

Muscle sympathetic nervous activity in depressed patients before and after treatment with sertraline

BACKGROUND

Sympathetic hyperactivity is one of the mechanisms involved in the increased cardiovascular risk associated with depression, and there is evidence that antidepressants decrease sympathetic activity.

OBJECTIVES

We tested the following two hypotheses: patients with major depressive disorder with high scores of depressive symptoms (HMDD) have augmented muscle sympathetic nervous system activity (MSNA) at rest and during mental stress compared with patients with major depressive disorder with low scores of depressive symptoms (LMDD) and controls; sertraline decreases MSNA in depressed patients.

METHODS

Ten HMDD, nine LMDD and 11 body weight-matched controls were studied. MSNA was directly measured from the peroneal nerve using microneurography for 3 min at rest and 4 min during the Stroop color word test. For the LMDD and HMDD groups, the tests were repeated after treatment with sertraline (103.3 +/- 40 mg).

RESULTS

Resting MSNA was significantly higher in the HMDD [29.1 bursts/min (SE 2.9)] compared with LMDD [19.9 (1.6)] and controls [22.2 (2.0)] groups (P = 0.026 and 0.046, respectively). There was a significant positive correlation between resting MSNA and severity of depression. MSNA increased significantly and similarly during stress in all the studied groups. Sertraline significantly decreased resting MSNA in the LMDD group and MSNA during mental stress in LMDD and HMDD groups. Sertraline significantly decreased resting heart rate and heart rate response to mental stress in the HMDD group.

CONCLUSION

Moderate-to-severe depression is associated with increased MSNA. Sertraline treatment reduces MSNA at rest and during mental challenge in depressed patients, which may have prognostic implications in this group.

Interactive effect of long-term mental stress and cardiac stress reactivity on carotid intima-media thickness: the Cardiovascular Risk in Young Finns study

The present study examined the interaction between vital exhaustion and cardiac reactivity and recovery on preclinical atherosclerosis assessed by carotid intima-media thickness (IMT) in young men and women. We measured heart rate (HR), respiratory sinus arrhythmia (RSA), and pre-ejection period (PEP) in response to mental arithmetic and speech tasks. Vital exhaustion and carotid IMT were also measured. Significant associations were observed for men aged 28-37 years, but not for men aged 22-25 years, nor for women in these age groups. It was shown that, among highly exhausted men in the older age group, lower HR reactivity was related to greater IMT. Our results also imply that, among non-exhausted men in this age group, slow HR and RSA recovery after acute stress predicted higher IMT. These results suggest that long-term stress as assessed by vital exhaustion is a risk only if it has resulted in ineffective cardiac stress reactivity. Autonomic imbalance resulting from chronic stress may be the common mechanism linking vital exhaustion and cardiac responsiveness to an increased risk of atherosclerosis.

Effect of metoprolol on vulnerable plaque in rabbits by changing shear stress around plaque and reducing inflammation

The beta-adrenoceptor antagonists are known to reduce cardiovascular events, but less is known about their effects on vulnerable plaque. The purpose of this study is to explore the role of metoprolol on vulnerable plaque and the possible mechanism. Vulnerable plaque model was established by local transfection with p53 gene in New Zealand Rabbits. Metoprolol treatment attenuated vessel positive remodeling and reduced vulnerability index (1.61+/-0.58 vs. 2.33+/-0.12, P<0.01). Although the difference did not reach statistical significance, the rate of rupture of atherosclerotic plaque (31% vs. 75%) and intima-media thickness (0.05+/-0.01 vs. 0.08+/-0.01 cm) were less in the metoprolol group than in the control group. The level of shear stress-related inflammatory cytokines such as intercellular adhesion molecule 1 (ICAM-1), vascular adhesion molecule 1 (VCAM-1), matrix metalloproteinase 1 (MMP-1), were lower in the metoprolol group than in the control group (P<0.01). Compared with control group, total cholesterol and low-density lipoprotein cholesterol were lower (P<0.01) in the metoprolol group. After metoprolol treatment, shear stress increased, and was not different to baseline (physiological shear stress, P>0.05). Shear stress and vulnerability index showed a negative correlation. These findings suggest that metoprolol could inhibit the development of atherosclerosis and stabilize vulnerable plaque by regulation of lipid and reduction of inflammation, in which the change from low shear stress to physiological shear stress around plaque may play an important role.

Reduced low-frequency heart rate variability relates to greater intimal-medial thickness of the carotid wall in two samples

INTRODUCTION

We investigated the relationship between heart rate variability and preclinical carotid intima-media thickening, a putative index of atherosclerosis.

METHODS

A sample of 350 men and women (mean age 56.8 years) selected for the presence or absence of untreated hypertension was assessed for heart rate variability at rest and separately for carotid intima-media thickness using duplex ultrasonography (Pittsburgh study). Findings from this sample were cross-validated in a subsample of 68 men drawn from the Kuopio Ischemic Heart Disease Risk Factor trial and selected for the presence or absence of angina.

RESULTS

In both samples, regression analyses, controlling for known risk factors, showed a significant negative relationship between mean carotid intima-media thickness and low-frequency (0.05-0.15 Hz) heart rate variability, but not high-frequency variability.

DISCUSSION

The mechanism underlying this relationship remains unclear. The absence of difference in high-frequency variation questions any interpretation in terms of vagal function; the difference in low-frequency variation may implicate vessel wall characteristics or decreased sympathetic nervous system influence.

CONCLUSION

Decreased amplitude of low-frequency heart rate variability seems associated with a preclinical atherosclerotic index.

Selective breeding for infant rat separation-induced ultrasonic vocalizations: developmental precursors of passive and active coping styles

Human depression and anxiety disorders show inherited biases across generations, as do antisocial disorders characterized by aggression. Each condition is preceded in children by behavioral inhibition or aggressive behavior, respectively, and both are characterized by separation anxiety disorders. In affected families, adults and children exhibit different forms of altered autonomic nervous system regulation and hypothalamic-pituitary-adrenal activity in response to stress. Because it is difficult to determine mechanisms accounting for these associations, animal studies are useful for studying the fundamental relationships between biological and behavioral traits. Pharmacologic and behavioral studies suggest that infant rat ultrasonic vocalizations (USV) are a measure of an early anxiety-like state related to separation anxiety. However, it was not known whether or not early ultrasound emissions in infant rats are markers for genetic risk for anxiety states later in life. To address these questions, we selectively bred two lines of rats based on high and low rates of USV to isolation at postnatal (P) 10 days of age. To our knowledge, ours is the only laboratory that has ever selectively bred on the basis of an infantile trait related to anxiety. The High and Low USV lines show two distinct sets of patterns of behavior, physiology and neurochemistry from infancy through adulthood. As adults High line rats demonstrate "anxious"/"depressed" phenotypes in behavior and autonomic nervous system (ANS) regulation to standard laboratory tests. In Lows, on the other hand, behavior and autonomic regulation are consistent with an "aggressive" phenotype. The High and Low USV lines are the first genetic animal models implicating long-term associations of contrasting "coping styles" with early attachment responses. They thus present a potentially powerful model for examining gene-environment interactions in the development of life-long affective regulation.

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.

Association between reduced heart rate variability and cognitive impairment in older disabled women in the community: Women's Health and Aging Study I

OBJECTIVES

To examine the independent association between heart rate variability (HRV), a marker of cardiac autonomic function, and cognitive impairment.

DESIGN

Cross-sectional analysis of baseline data from Women's Health and Aging Study I.

SETTING

Urban community in Baltimore, Maryland.

PARTICIPANTS

A subset of 311 physically disabled, community-dwelling women aged 65 and older whose HRV data were obtained.

MEASUREMENTS

Reduced HRV was defined as the lowest quartile of each of several HRV measures exploring time and frequency domains and compared with the remaining three quartiles. Cognitive impairment was defined as a Mini-Mental State Examination score less than 24. Multiple logistic regression was used to model the independent relationship between reduced HRV and prevalent cognitive impairment.

RESULTS

The age-, education-, and race-adjusted prevalence of cognitive impairment was higher in those with reduced HRV than in those with nonreduced HRV. After adjusting for relevant demographic and clinical characteristics, participants with reduced HRV were significantly more likely than those with nonreduced HRV to have cognitive impairment; these findings were consistent across different HRV indices. In particular, reduced high-frequency power, indicative of decreased parasympathetic activity, was associated with 6.7 times greater odds of cognitive impairment (95% confidence interval = 2.27-20.0).

CONCLUSION

Cardiac autonomic dysfunction, particularly decreased parasympathetic activity, was independently associated with cognitive impairment in older disabled women in the community. This finding may improve understanding of the pathophysiological basis of cognitive impairment. The potential role of HRV as a cause or consequence of cognitive impairment needs to be elucidated in future studies.

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.

Treatment of depression in patients with coronary heart disease

Depression and coronary heart disease are common conditions that often occur together. Evidence shows that the co-occurrence of these illnesses is not random but driven by depression as a risk factor for the occurrence and progression of coronary heart disease. This link is due, in part, to the impact that depression has on neuroendocrine pathways leading to increased platelet activation, cortisol and catecholamine excess, and altered autonomic nervous system function that influence the pathogenesis and progression of coronary atherosclerosis and subsequent heart disease. We know that treating depression in patients with coronary heart disease improves the symptoms and signs of depression. Evidence is less compelling that treating depression improves the morbidity and mortality of coronary heart disease. However, early findings suggest that some antidepressants may improve the course of coronary heart disease and improve patient compliance with various cardiac interventions. We outline a practical approach to the treatment of depression in patients with coronary heart disease. This approach includes education, counseling, antidepressant drugs, and referral when appropriate.

Hostility and sex differences in the magnitude, duration, and determinants of heart rate response to forehead cold pressor: Parasympathetic aspects of risk

Recent models hypothesize that hostility confers increased risk of CHD through weaker parasympathetic dampening of cardiovascular reactivity (CVR). We tested this possibility using the forehead cold pressor task, a common maneuver which elicits the "dive reflex" characterized by a reflexive decrease in HR presumably through cardiac-parasympathetic stimulation. Participants were initially chosen from the outer quartiles of a sample of 670 undergraduates screened using the hostility subscale of the Aggression Questionnaire ([Buss, A.H., Perry, M., 1992. The Aggression Questionnaire. Journal of Personality and Social Psychology, 63, 452-459.]). The final sample of 80 participants was evenly divided between men and women and high and low hostility. Following a 10-min baseline, participants underwent a 3-min forehead cold pressor task. The task evoked a significant HR deceleration that was mediated by PNS activation, as assessed by respiratory sinus arrhythmia (RSA). Replicating prior research, men displayed greater decrease in HR. More important, low hostiles maintained larger HR deceleration over time compared to high hostiles although the autonomic basis for this effect was unclear. The findings broaden understanding of hostility and sex-related cardiovascular functioning and support the task as a method for evoking PNS-cardiac stimulation.

Prolonged stress-related cardiovascular activation: Is there any?

BACKGROUND

Prolonged physiological activation before or after stressors has gained recognition as a decisive element in theories that explain the link between stress and disease, specifically cardiovascular (CV) disease. This view is opposed to the conventional reactivity hypothesis that emphasizes responses during stressors.

PURPOSE

Prolonged activity has not often been an explicit research goal of real-life stress studies. Nevertheless, a growing number of these studies have provided evidence for prolonged activity, often as a secondary research goal.

METHODS

An overview of this evidence is lacking and is provided in this article.

RESULTS

The combined data from the reviewed studies suggest that discrete and chronic stress sources, as well as negative emotional episodes and dispositions, are related to prolonged CV activity of various durations, including sleep periods. On the other hand, evidence supporting the assumption that prolonged stress-related activation predicts disease is still very modest.

CONCLUSIONS

In this article we suggest that future research of prolonged activation should give priority to (a) the establishment of clear beginnings and endings of stressful events, (b) the prediction of disease by prolonged activation, and (c) potential psychological mediators of stress-related prolonged activation. These mediators may include, for example, worry and rumination, or other processes characterized by perseverative cognition, including unconscious processes.

The role of angry rumination and distraction in blood pressure recovery from emotional arousal

OBJECTIVE

Cardiovascular recovery of prestress baseline blood pressure has been implicated as a possible additional determinant of sustained blood pressure elevation. We hypothesize that angry ruminations may slow the recovery process.

METHOD

A within-subjects design was used in which resting baseline blood pressure and heart rate measurements were assessed on 60 subjects, who then took part in two anger-recall tasks. After each task, subjects sat quietly and alone during a 12-minute recovery period randomized to with or without distractions. During baseline, task, and recovery, blood pressure was continuously monitored; during recovery, subjects reported their thoughts at five fixed intervals.

RESULTS

Fewer angry thoughts were reported in the distraction condition (17%) compared with no distraction (31%; p = .002); an interaction showed that this effect was largely the result of the two intervals immediately after the anger-recall task. Trait rumination interacted with distraction condition such that high ruminators in the no-distraction condition evidenced the poorest blood pressure recovery, assessed as area under the curve (p = .044 [systolic blood pressure] and p = .046 [diastolic pressure]).

CONCLUSIONS

People who have a tendency to ruminate about past anger-provoking events may be at greater risk for target organ damage as a result of sustained blood pressure elevations; the effect is exacerbated when distractions are not available to interrupt the ruminative process.

Gender and communal trait differences in the relations among social behaviour, affect arousal, and cardiac autonomic control

To examine the relation between social behaviour and vagal activity, the communal behaviour of healthy college men (N = 33) and women (N = 33) was manipulated while monitoring heart rate (HR) and respiratory sinus arrhythmia (RSA). The subjects were classified as low or high on communal trait. Communal behaviour was manipulated by having the subjects behave in an agreeable or quarrelsome manner in scripted role-plays. HR, RSA and self-report arousal were obtained during or immediately following baseline, experimental and relaxation periods. 2 (Gender) x 2 (Communal Trait; low/high) x 2 (Condition; agreeable/quarrelsome) ANCOVAs were performed. Men had lower RSA values when behaving in a quarrelsome fashion than agreeable and lower RSA values than women in the quarrelsome condition. In the latter condition, low communal men reported more arousal than other groups. Strong but opposite associations between RSA and affect arousal were observed in low communal men and woman. Men, especially more quarrelsome (less communal) men exhibited weaker vagal control during arousing social situations.

The influence of hostility and family history of cardiovascular disease on autonomic activation in response to controllable versus noncontrollable stress, anger imagery induction, and relaxation imagery

Autonomic activation in response to controllable versus noncontrollable stress, anger imagery induction, and relaxation imagery was studied among 80 participants between the ages of 18 and 34 years. Participants differed in level of trait hostility and family history of cardiovascular disease. Results were obtained through power spectral analyses of electrocardiograph R-R intervals, which produced an index of autonomic nervous system activation. For both male and female populations, parasympathetic regulation was diminished during anger induction for individuals with high levels of trait hostility and having a family history of cardiovascular disease. Similar results were obtained for women during the uncontrolled stress condition. Based on family history of cardiovascular disease and trait hostility, men responded differentially to relaxation imagery induction, whereas no differences were found among females.

Development and evolution of hidden regulators: Selective breeding for an infantile phenotype

Mother-infant separation in the rat has been used as an analytical tool to reveal biosocial processes underlying infant physiology and behavior. The same strategy has guided a project in which selective breeding for an infantile behavior has provided insights into how biological systems become recruited and integrated as expressions of temperamental affective responses. Two lines of rats (High and Low USV lines) were selectively bred based on rates of USV emission to maternal separation and isolation at postnatal day (P) 10. After many generations of breeding, the High and Low lines show widespread and distinctly different profiles of physiology and behavior in the first 3 weeks of life. Insights gained from longitudinal studies suggest that selection may work by reorganizing developmental processes, not just a given trait, over the postnatal period. As animal models, the lines have the potential to provide valuable tools for understanding developmental mechanisms underlying genetic and developmental risk for depression/anxiety syndromes in children and adults.

Psychological distress and exertional angina in men and women undergoing thallium scintigraphy

The relation between psychological factors and angina has mostly been studied in male patients with confirmed CAD and few have evaluated this relation during actual provocation of ischemia. This study evaluated gender differences in the association between psychological distress and angina pain experience in 907 Caucasian patients (479 women, mean age = 60 years) undergoing exercise stress testing with thallium scintigraphy. Data were analyzed separately for patients with and without exercise related ischemia using a series of 2 (low/high distress) x 2 (gender) ANOVAs as well as binary logistic regressions. Among all patients, distress and gender were associated with greater risk and intensity of angina pain during testing (p < 0.05) and more angina following exertion (p < 0.05) or stress (p < 0.05) at home.

CONCLUSION

angina pain was more severe in women and individuals with high levels of distress, regardless of their ischemic status. A generalized hypersensitivity to pain/symptoms may be indicated in these patients.

Chronomic community screening reveals about 31% depression, elevated blood pressure and infradian vascular rhythm alteration

Depression, which is a risk factor for cardiac morbidity and mortality, is not an unusual occurrence among individuals with coronary heart disease (CHD), but evidence concerning its role in the pathogenesis of this condition is less clear. Ambulatory blood pressure monitoring (ABPM) has become an important tool in the diagnosis and management of hypertension. Several previous studies have indicated that various kinds of target organ damage and cardiovascular morbidity are more strongly associated with a diagnosis by ABPM than through spot-checks in a clinical setting. This study investigated whether depressive mood was associated with changes in the about-weekly (circaseptan) and half-weekly (circasemiseptan) variations in blood pressure (BP) and heart rate (HR), including a BP surge on Mondays, in community-dwelling subjects monitored chronomically for the time structure (chronome) of their BP and HR variabilities. From April 2001 to April 2003, 217 subjects (85 men and 132 women; mean age: 56.8 +/- 11.3 yr) from U town, Hokkaido (latitude: 43.45 degrees N, longitude: 141.85 degrees E), self-monitored their BP and HR for 7 days starting around 11 a.m. on Thursday, and took readings at 30-minute intervals between 7 a.m. and 10 p.m., then at 60-minute intervals between 10 p.m. and 7 a.m. The data were retrieved and analyzed on a PC with appropriate commercial software (TM-2430-15; A&D Co., Japan). Subjects were asked about 15 items on a depression rating scale through a self-administered questionnaire. When the score amounted to 5 or higher, subjects were considered to be depressive. Student's t-test, a one-way analysis of variance (ANOVA), and cosinor methods with parametric tests were also used. A p-value below 0.05 was considered to indicate statistical significance (below 0.10: borderline statistical significance). Depression rating scales were obtained for 192 out of the 217 subjects enrolled in this study. Depression scores were (>) 5 in 72 subjects. The average values of systolic (S) and diastolic (D) BP were statistically significantly higher in depressed subjects (SBP: 129.2 vs 124.5 mmHg; p = 0.034; DBP: 79.0 vs 76.5 mmHg; p = 0.041). The 7-day average for HR did not differ between subjects with depression scores of < 5 or > 5. DBP dipping was less in the depressed subjects (16.30 vs 18.22%; p = 0.048). The dipping ratios of SBP and HR showed no statistically significant difference. In the group with depression scores of < 5, HR variability (estimated by the SD of HR and HR dip) was higher during vacations and lower on Mondays. The 24-h BP measures showed a novelty effect and a surge on Mondays. In the depressed group, a prominent circaseptan rhythm appeared to replace the novelty effect, vacation dip, and Monday surge. The results of this investigation indicate the clinical importance of the monitoring of depressed subjects. Fewer than 7 days of monitoring means a greater risk of false diagnosis, and thus a therapeutic decision including potentially unnecessary or inappropriate long-term treatment. Records shorter than 7 days would not have detected circaseptan BP dysrhythmia associated with a depressive state. Prominent circaseptans can provide new indications on the mechanisms underlying the strong relation between depression and adverse cardiac events. Future studies should aim at determining whether the treatment of depression, especially from the standpoint of a chronodiagnosis and chronotherapy, can reduce the incidence of adverse cardiac events, and whether this depends upon restoring normal BP and HR variability, i.e. anormal BP and HR chronome.

The roles of marriage and anger dysregulation in biobehavioral stress responses

Physiological and behavioral correlates of anger dysregulation in adults were evaluated in the context of marital stress. Fifty-four married couples participated in a series of laboratory procedures that included electrocardiogram measures during a 15-min marital conflict interaction and an interview assessing their inability to regulate anger (anger dysregulation). Results from the multivariate regression analyses indicated that the nature of the couple's relationship, rather than individual levels of anger dysregulation, predicted lower parasympathetic cardiac activity (indexed by high-frequency heart period variability) and shorter cardiac interbeat intervals. Anger dysregulation, rather than the dyadic relationship, was predictive of greater displays of angry behavior during the marital conflict interaction. The importance of contextual factors in stress processes, such as stress due to marriage, are discussed in light of research linking poor marital quality to greater health risks for women than for men.

A greater reduction in high-frequency heart rate variability to a psychological stressor is associated with subclinical coronary and aortic calcification in postmenopausal women

OBJECTIVE

Reduced cardiac parasympathetic activity, as indicated by a reduced level of clinic or ambulatory high-frequency heart rate variability (HF-HRV), is associated with an increased risk for atherosclerosis and coronary artery disease. We tested whether the reduction in HF-HRV to a psychological stressor relative to a baseline level is also associated with subclinical coronary or aortic atherosclerosis, as assessed by calcification in these vascular regions.

METHOD

Spectral estimates of 0.15 to 0.40 Hz HF-HRV were obtained from 94 postmenopausal women (61-69 years) who engaged in a 3-minute speech-preparation stressor after a 6-minute resting baseline. A median of 282 days later, electron beam tomography (EBT) was used to measure the extent of coronary and aortic calcification.

RESULTS

In univariate analyses, a greater reduction in HF-HRV from baseline to speech preparation was associated with having more extensive calcification in the coronary arteries (rho = -0.29, p = .03) and in the aorta (rho = -0.22, p = .06). In multivariate analyses that controlled for age, education level, smoking status, hormone therapy use, fasting glucose, high-density lipoproteins, baseline HF-HRV, and the stressor-induced change in respiration rate, a greater stressor-induced reduction in HF-HRV was associated with more calcification in the coronary arteries (B = -1.21, p < .05), and it was marginally associated with more calcification in the aorta (B = -0.92, p = .09).

CONCLUSION

In postmenopausal women, a greater reduction in cardiac parasympathetic activity to a psychological stressor from baseline may be an independent correlate of subclinical atherosclerosis, particularly in the coronary arteries.

Hypertension and depression

Despite the high prevalence of depression and hypertension, the relationship between the two diseases has received little attention. This paper reviews the epidemiological, pathophysiological, and prognostic aspects of this association, as well as its implications for treatment. A Medline search was conducted using the following key words: depression, blood pressure, blood pressure variability, physical morbidity, hypertension, mood, stress, hypertension, antidepressive agents, and genetics, from 1980 to 2004. We found descriptions of increased prevalence of hypertension in depressed patients, increased prevalence of depression in hypertensive patients, association between depressive symptomatology and hypotension, and alteration of the circadian variation of blood pressure in depressed patients. There is considerable evidence suggesting that hyperreactivity of the sympathetic nervous system and genetic influences are the underlying mechanisms in the relationship between depression and hypertension. Depression can negatively affect the course of hypertensive illness. Additionally, the use of antidepressive agents can interfere with blood pressure control of patients with hypertension by inducing changes in blood pressure and orthostatic hypotension.

Selective breeding for an infant phenotype: rat pup ultrasonic vocalization (USV)

To examine processes underlying generational and developmental influences on anxiety, this laboratory produced two lines of (N:NIH strain) rats, selectively bred on the basis extreme rates of ultrasonic vocalization in 2 minutes of isolation at Postnatal Day 10. The research reviewed in this article focuses on: (1) establishment of the selectively bred lines; (2) defining infant behavioral and physiological phenotypes and (3) determining whether infantile USV phenotypes endure over development. The High and Low lines have diverged widely in their USV rates from each other and from the Random control line, which has maintained N:NIH strain rates overall from generation to generation. Beginning in the 11th generation, High USV pups have shown significantly higher frequencies of defecation and urination during isolation screening than the Low USV and random control line. Both lines show altered autonomic regulation of heart rates (HR) in response to stressors as juveniles and adults. These differences in HR responses in High and Low lines appear to be mediated by changes in the balance of sympathetic versus parasympathetic mechanisms. Other behavioral characteristics of the High line are consistent with an "anxious"/ "depressive" phenotype, such as vocalizations to touch in a novel environment, and performance in the Porsolt Swim, whereas Low line shows few differences in anxiety behavior. Future work will resolve the similarities and differences in the High and Low phenotypes and provide a developmental perspective to the growing body of information about affective regulation in humans and animals provided by selectively bred animal models.