MENTAL STRESS AS A TRIGGER OF MYOCARDIAL ISCHEMIA AND INFARCTION**Preparation of this article was assisted by a grant from the NIH (HL47337) and USUHS grant RO7233. The opinions and assertions expressed herein are those of the authors and are not to be construed as reflecting the views of the USUHS or the US Department of Defense

Alignment Between Heart Rate Variability From Fitness Trackers and Perceived Stress: Perspectives From a Large-Scale In Situ Longitudinal Study of Information Workers

BACKGROUND

Stress can have adverse effects on health and well-being. Informed by laboratory findings that heart rate variability (HRV) decreases in response to an induced stress response, recent efforts to monitor perceived stress in the wild have focused on HRV measured using wearable devices. However, it is not clear that the well-established association between perceived stress and HRV replicates in naturalistic settings without explicit stress inductions and research-grade sensors.

OBJECTIVE

This study aims to quantify the strength of the associations between HRV and perceived daily stress using wearable devices in real-world settings.

METHODS

In the main study, 657 participants wore a fitness tracker and completed 14,695 ecological momentary assessments (EMAs) assessing perceived stress, anxiety, positive affect, and negative affect across 8 weeks. In the follow-up study, approximately a year later, 49.8% (327/657) of the same participants wore the same fitness tracker and completed 1373 EMAs assessing perceived stress at the most stressful time of the day over a 1-week period. We used mixed-effects generalized linear models to predict EMA responses from HRV features calculated over varying time windows from 5 minutes to 24 hours.

RESULTS

Across all time windows, the models explained an average of 1% (SD 0.5%; marginal R2) of the variance. Models using HRV features computed from an 8 AM to 6 PM time window (namely work hours) outperformed other time windows using HRV features calculated closer to the survey response time but still explained a small amount (2.2%) of the variance. HRV features that were associated with perceived stress were the low frequency to high frequency ratio, very low frequency power, triangular index, and SD of the averages of normal-to-normal intervals. In addition, we found that although HRV was also predictive of other related measures, namely, anxiety, negative affect, and positive affect, it was a significant predictor of stress after controlling for these other constructs. In the follow-up study, calculating HRV when participants reported their most stressful time of the day was less predictive and provided a worse fit (R2=0.022) than the work hours time window (R2=0.032).

CONCLUSIONS

A significant but small relationship between perceived stress and HRV was found. Thus, although HRV is associated with perceived stress in laboratory settings, the strength of that association diminishes in real-life settings. HRV might be more reflective of perceived stress in the presence of specific and isolated stressors and research-grade sensing. Relying on wearable-derived HRV alone might not be sufficient to detect stress in naturalistic settings and should not be considered a proxy for perceived stress but rather a component of a complex phenomenon.

Ischemia and no obstructive coronary arteries in patients with stable ischemic heart disease

A large proportion of patients with suspected obstructive coronary artery disease (CAD) is found to have ischemia with no obstructive coronary artery disease (INOCA). Based on current evidence, these patients are at increased risk of adverse cardiovascular events, even though they have no obstructive CAD. Importantly, INOCA is associated with recurrent clinical presentations with chest pain, impaired functional capacity, reduced health-related quality of life, and high healthcare costs. Underlying coronary microvascular dysfunction (CMD), through endothelium-dependent and independent mechanisms contribute to these adverse outcomes in INOCA. While non-invasive and invasive diagnostic testing has typically focused on identification of obstructive CAD in symptomatic patients, functional testing to detect coronary epicardial and microvascular dysfunction should be considered in those with INOCA who have persistent angina. Current diagnostic methods to clarify functional abnormalities and treatment strategies for epicardial and/or microvascular dysfunction in INOCA are reviewed.

Arterial stiffness in underweight and weight-restored anorexia nervosa

Cardiovascular complications have been demonstrated in patients with anorexia nervosa (AN) in both the state of starvation and during weight restoration, however, the underlying mechanisms remain unclear. The current study aimed to assess arterial stiffness via carotid-femoral pulse wave velocity (cfPWV) in the acute and weight-restored states of AN. The study also aimed to determine the association between psychological distress and cfPWV. The sample included 37 participants; 10 participants with AN, 17 who were weight-restored (AN-WR; minimum body mass index >18.5 for at least 12 months) and 10 healthy controls (HCs). cfPWV via applanation tonometry was conducted to assess arterial stiffness. Psychological distress was assessed using the depression anxiety stress scale (DASS-21) and the state-trait anxiety inventory (STAI). Between-group comparisons were performed to determine differences between groups, a two-stage hierarchical regression model was performed to determine the contribution of physiological and psychological variables on cfPWV and correlation analyses were also performed. Vascular stiffness was significantly increased in the AN and AN-WR groups, relative to HCs. The total DASS score was the only significant predictor of cfPWV across the sample. There were positive associations between cfPWV and depression, anxiety and stress, as assessed by the DASS. Furthermore, cfPWV was positively associated with STAI trait anxiety. Arterial stiffness was increased in individuals in the acute and weight-restored states of AN, demonstrating early signs of the development of arteriosclerotic cardiovascular disease. Increased arterial stiffness was associated with increased psychological distress, which may be a contributing mechanism to the increased cardiovascular risk in AN.

Facial Expressions of Emotions During Pharmacological and Exercise Stress Testing: the Role of Myocardial Ischemia and Cardiac Symptoms

Background

Negative emotions have been linked to ischemic heart disease, but existing research typically involves self-report methods and little is known about non-verbal facial emotion expression. The role of ischemia and anginal symptoms in emotion expression was examined.

Methods

Patients undergoing cardiac stress testing (CST) using bicycle exercise or adenosine with myocardial perfusion imaging were included (N = 256, mean age 66.8 ± 8.7 year., 43% women). Video images and emotion expression (sadness, anxiety, anger, and happiness) were analyzed at baseline, initial CST , maximal CST, recovery. Nuclear images were evaluated using SPECT.

Results

Ischemia (N = 89; 35%) was associated with higher levels of sadness (p = .017, d = 0.34) and lower happiness (p = .015, d = 0.30). During recovery, patients with both ischemia and anginal symptoms had the highest sadness expression (F (3,254) = 3.67, p = .013, eta² = 0.042) and the lowest happiness expression (F (3, 254) = 4.19, p = .006, eta² = .048).

Conclusion

Sadness and reduced happiness were more common in patients with ischemia. Also, anginal symptoms were associated with more negative emotions.

Diabetes and atherothrombosis: The circadian rhythm and role of melatonin in vascular protection

Obesity-related euglycaemic insulin resistance clusters with cardiometabolic risk factors, contributing to the development of both type 2 diabetes and cardiovascular disease. An increased thrombotic tendency in diabetes stems from platelet hyperactivity, enhanced activity of prothrombotic coagulation factors and impaired fibrinolysis. Furthermore, a low-grade inflammatory response and increased oxidative stress accelerate the atherosclerotic process and, together with an enhanced thrombotic environment, result in premature and more severe cardiovascular disease. The disruption of circadian cycles in man secondary to chronic obesity and loss of circadian cues is implicated in the increased risk of developing diabetes and cardiovascular disease. Levels of melatonin, the endogenous synchronizer of circadian rhythm, are reduced in individuals with vascular disease and those with deranged glucose metabolism. The anti-inflammatory, antihypertensive, antioxidative and antithrombotic activities of melatonin make it a potential therapeutic agent to reduce the risk of vascular occlusive disease in diabetes. The mechanisms behind melatonin-associated reduction in procoagulant response are not fully known. Current evidence suggests that melatonin inhibits platelet aggregation and might affect the coagulation cascade, altering fibrin clot structure and/or resistance to fibrinolysis. Large-scale clinical trials are warranted to investigate the effects of modulating the circadian clock on insulin resistance, glycaemia and cardiovascular outcome.

Psychopharmacology and Cardiovascular Disease

This review discusses common mental health disorders and their associations with cardiovascular disease risks. Commonly found mental health disorders include depression, anxiety, and personality types. The link between depression and cardiovascular disease mortality has been established. Depression is also common in patients with heart failure. In addition to discussing psychological disorders, a review of psychotropic drugs is also included. Drugs are described for therapy for depression and anxiety, as well as associations with cardiovascular drug-drug interactions. Drug-drug interactions are more common and potentially dangerous in elderly patients, in whom the conditions often coexist. The most common drug-drug interactions involve the P450 system of enzymes.

The impact of acute mental stress on brachial artery flow-mediated dilation in women diagnosed with depression

Endothelial function, assessed by flow-mediated dilation (FMD), may be transiently attenuated in healthy adults following acute mental stress. However, the impact of acute mental stress on endothelial function in the context of clinical depression is unknown. This study examined the impact of acute mental stress on FMD in women with a diagnosis of a depressive disorder. Forty-three otherwise healthy women (33 ± 14 years) participated. Brachial artery diameter and blood velocity were assessed with ultrasound. FMD was assessed immediately prior to and 15 min following the Trier Social Stress Test (TSST). The FMD protocol included 5 min of forearm cuff occlusion (pressure = 250 mm Hg), followed by release. Shear stress was estimated by calculating shear rate (SR = brachial artery blood velocity/diameter). Stress reactivity was assessed via changes in mean arterial pressure (MAP), heart rate (HR) and salivary cortisol. Results are mean ± SD. A significant stress response was elicited by the TSST [MAP, HR and salivary cortisol increased (p < 0.05)]. Neither the SR stimulus nor FMD response differed pre-versus post-stress (p = 0.124 and p = 0.641, respectively). There was a modest negative correlation between cortisol reactivity and change in FMD from pre- to post-stress (R = -0.392, p = 0.011). To conclude, acute mental stress did not consistently impair endothelial function in women diagnosed with a depressive disorder; however, higher cortisol reactivity may increase the likelihood of post-stress endothelial dysfunction. Further research is required to better understand the factors influencing the relationship between acute mental stress, cortisol and endothelial function in women with depression.

Effects of depression on heart rate variability in elderly patients with stable coronary artery disease

BACKGROUND

Depression is an independent risk factor in coronary artery disease (CAD). Our objective was to evaluate the impact of depression on heart rate variability (HRV) in patients with stable CAD.

METHODS

This study included patients with a stable CAD who admitted to our hospital in the geriatric medical center from August 2016 to December 2016. All patients agreed to participate in the study and sign informed consent. The study group included 90 CAD patients with a diagnosis of depression and 99 CAD patients without depression. All study population underwent a 24-hour Holter recording for HRV. The depression was assessed by 5-Item Geriatric Depression.

RESULTS

There was a linear correlation between age and HRV. There were no significant differences in heart rate variability between male and female patients, married and unmarried/widowed, smoking and nonsmoking, drinking and nondrinking groups. Multiple linear regression analysis showed that there were correlations between depression and HRV. β-blockers were associated with SDNN, SDANN, SDNN index, and RMSSD in HRV.

CONCLUSION

Depression is an important risk factor for heart rate variability in elderly patients with CAD. Clinicians should pay attention for evaluation of depressive patients with CAD.

Mental stress peripheral vascular reactivity is elevated in women with coronary vascular dysfunction: Results from the NHLBI-sponsored Cardiac Autonomic Nervous System (CANS) study

BACKGROUND

Women with chest pain, ischemia, and no obstructive coronary artery disease often have coronary vascular dysfunction (CVaD). Peripheral vascular reactivity to mental stress may contribute mechanistic understanding of stress-induced ischemia in women with CVaD.

METHODS

62 women (41 CVaD and 21 controls) underwent mental stress testing (MST) with anger recall, mental arithmetic, and forehead cold pressor (COP) challenge. Emotional arousal was measured (Likert scale). Reactive hyperemia index (RHI) was calculated before and after MST by peripheral arterial tonometry (PAT). Stress PAT ratio (SPR) of pulse amplitude during stress to rest was obtained to measure vasoconstriction. Wilcoxson rank sum test was used for analysis.

RESULTS

Mean age of CVaD and control groups was 58±9 and 55±10years (p=0.73). Baseline RHI correlated with coronary endothelial function (r=0.36, p=0.03) and inversely with RHI change post-MST (r=-0.51, p<0.001). During MST, 10% of controls reported chest pain vs. 41% of CVaD subjects (p=0.01). RHI did not change significantly after MST in either group. CVaD subjects had lower SPR vs. controls during mental arithmetic (0.54 [0.15, 1.46] vs. 0.67 [0.36, 1.8], p=0.039), not evident in the other tasks. Vasoconstriction inversely correlated with anxiety (r=-3.4, p=0.03), frustration (r=-0.37, p=0.02), and feeling challenged (r=-0.37, p=0.02) in CVaD but not controls.

CONCLUSIONS

Mental stress peripheral vascular reactivity is elevated in women with CVaD compared to controls. Elevated vascular reactivity may be one contributor to stress-induced chest pain in CVaD. Interventions that modulate vasoconstrictive responses may be of benefit and should be tested in clinical trials in women with CVaD.

Panic disorder and cardiovascular diseases: an overview

The association between panic disorder (PD) and cardiovascular diseases (CVD) has been extensively studied in recent years and, although some studies have shown anxiety disorders co-existing or increasing the risk of heart disease, no causal hypothesis has been well established. Thus, a critical review was performed of the studies that evaluated the association between PD and cardiovascular diseases; synthesizing the evidence on the mechanisms mediators that theoretically would be the responsible for the causal pathway between PD and CVD, specifically. This overview shows epidemiological studies, and discusses biological mechanisms that could link PD to CVD, such as pleiotropy, heart rate variability, unhealthy lifestyle, atherosclerosis, mental stress, and myocardial perfusion defects. This study tried to provide a comprehensive narrative synthesis of previously published information regarding PD and CVD and open new possibilities of clinical management and pathophysiological understanding. Some epidemiological studies have indicated that PD could be a risk factor for CVD, raising morbidity and mortality in PD, suggesting an association between them. These studies argue that PD pathophysiology could cause or potentiate CVD. However, there is no evidence in favour of a causal relationship between PD and CVD. Therefore, PD patients with suspicions of cardiovascular symptoms need redoubled attention.

Anxiety and anger immediately prior to myocardial infarction and long-term mortality: Characteristics of high-risk patients

OBJECTIVE

Acute high levels of anger and anxiety are associated with an elevated risk of myocardial infarction (MI) in the following two hours. MIs preceded by these acute negative emotions may also have a poor long-term prognosis, but information about high-risk patients is lacking. We examined whether young age and female sex are associated with MIs that are preceded by negative emotions and whether age and sex moderate the subsequent increased mortality risk following MI preceded by negative emotions.

METHODS

We conducted a secondary analysis of the Determinants of Myocardial Infarction Onset Study (N=2176, mean age=60.1±12.3years, 29.2% women). Anxiety and anger immediately prior to (0-2h) MI and the day before (24-26h) MI were assessed using a structured interview. Subsequent 10-year all-cause mortality was determined using the US National Death Index.

RESULTS

Anxiety during the 0-2h pre-MI period was associated with younger age (OR=0.98,95% CI=0.96-0.99 per year) and female sex (OR=1.50,95% CI=1.11-2.02). Anger in the 0-2h pre-MI period was also associated with younger age (OR=0.95,95% CI=0.94-0.96) but not with sex (OR=0.93,95% CI=0.67-1.28). During follow-up, 580 (26.7%) patients died. Mortality rate was higher if MI occurred immediately after high anxiety, particularly in patients ≥65years (HR=1.80,95% CI=1.28-2.54) vs. younger patients (HR=0.87,95% CI=0.55-1.40; p-interaction=0.015). Other interactions with sex or anger were not significant.

CONCLUSIONS

Patients with high anxiety or anger levels in the critical 2-hour period prior to MI are younger than those without such emotional precipitants. In addition, pre-MI anxiety is associated with an elevated 10-year mortality risk in patients aged ≥65years.

The impact of major depression on heart rate variability and endothelial dysfunction in patients with stable coronary artery disease

BACKGROUND

Depression is an independent risk factor in cardiovascular diseases. Changes in the cardiac autonomic functions and pro-inflammatory processes are potential biological factors. Endothelial dysfunction plays an important role in the etiopathogenesis of atherosclerosis. Our objective was to evaluate the impact of major depression on heart rate variability and endothelial dysfunction in patients with stable CAD.

METHODS

The study group included 65 CAD patients with a diagnosis of major depression and 54 CAD patients without major depression. All study population underwent transthoracic echocardiography, measurement of flow mediated dilatation (FMD) and 24-h holter recording for heart rate variability (HRV). Blood samples were drawn to determine the inflammatory parameters. Severity of depressive episode was assessed by Montgomery-Asberg Depression Scale (MADRS).

RESULTS

The distribution of age and sex was similar in the patient and control groups (P=0.715, 0.354, respectively). There was no significant difference in medications used between the groups. Echocardiographic parameters were similar between the groups. Inflammatory parameters were also similar between the groups. HRV parameters were significantly lower in the patient group than controls. The absolute FMD value and percentage FMD were significantly lower in the patient group than controls (P<0.001). The MADRS score correlated with pNN50 in both groups (P<0.05), and with FMD in the control group (P<0.001), even after adjusting for age and gender (P<0.001).

CONCLUSIONS

MADRS score was an independent predictor of pNN50 level, percentage and absolute FMD values regardless of age and gender. Clinician should pay more attention for evaluation of depressive patients with CAD.

The Effect of Early Education on Patient Anxiety While Waiting for Elective Cardiac Catheterization

Background: A supply–demand mismatch with respect to cardiac catheterization (CATH) often results in patients experiencing waiting times that vary from a few weeks to several months. Long delays can impose both physical and psychological distress for patients. Purpose: The purpose of this study was to examine the effect of a psychoeducational nursing intervention at the beginning of the waiting period on patient anxiety during the waiting time for elective CATH. Methods: This was a 2-group randomized controlled trial. Intervention patients received a nurse-delivered, detailed information/education session within 2 weeks of being placed on the waiting list for elective CATH. Control group patients received usual care. Results: The mean waiting time for CATH was 13.4±7.2 weeks, which did not differ between groups ( P=0.509). Anxiety increased in both groups over the waiting time ( P=0.028). Health-related quality of life deteriorated over the waiting time in both groups ( P<0.05). On a visual analogue scale, there was a significant difference ( P=0.002) between the intervention (4.0±2.7) and control (5.2±3.0) groups in self-reported anxiety 2 weeks prior to CATH. Conclusions: The waiting period prior to elective CATH has a negative impact on patients’ perceived anxiety and quality of life and a simple intervention, provided at the beginning of the waiting period, may positively affect the experience of waiting.

Young women post-MI have higher plasma concentrations of interleukin-6 before and after stress testing

OBJECTIVES

Young women have poorer prognosis after myocardial infarction (MI) and a higher rate of mental stress-induced ischemia compared with similarly aged men. A higher inflammatory status may help explain these sex differences.

METHODS

We examined 98 patients (49 women and 49 men) age 18-59years with recent MI (past 6months). Women and men were matched for age, type of MI, and time since MI. Interleukin 6 (IL-6) concentrations were measured at baseline, after mental stress using a speech task, and after exercise/pharmacologic stress (60 and 90min). Depressive symptoms were measured with the Beck Depression Inventory (BDI-II) and angiographic coronary artery disease (CAD) severity was quantified with the Gensini score. Single-photon emission computed tomography (SPECT) was used to obtain a computerized measurement of stress-induced ischemia (summed difference score, or SDS) and determine whether severity of stress-induced ischemia affects the inflammatory response to stress. Analysis was stratified by the median age of 50. Geometric mean concentrations of IL-6 were obtained from general linear regression models.

RESULTS

In both age groups, women had less angiographic CAD and a similar level of conventional risk factors compared with men. Despite this, baseline IL-6 geometric means before both mental and physical stress were twice as high in women ⩽50years of age compared to age-matched men (3.8 vs. 1.8pg/mL, p=0.001, across both conditions), while they were similar in women and men age >50years (2.3 vs. 2.2pg/mL, p=0.83). After mental stress, IL-6 concentrations increased in both women and men in a similar fashion and remained twice as high in women ⩽50years than men at both 60min (5.4 vs. 2.6pg/mL, p=0.002) and 90min (5.9 vs. 3.4pg/mL, p=0.01). No significant difference was found between women and men >50years of age at any time point after mental stress. Results were similar for physical stress. After accounting for SDS, IL-6 concentrations in young women remained higher after both mental and physical stress. Baseline IL-6 concentrations were not significantly related to inducible ischemia.

CONCLUSIONS

After MI, young women aged 50years or younger, compared with age-matched men, have remarkably higher concentrations of inflammation at baseline and after both mental and physical stress, with a similar inflammatory response to both stressors. Sustained concentrations of inflammation in young women, not their response to stress, may contribute to their adverse outcomes post-MI.

Acute Stress Decreases but Chronic Stress Increases Myocardial Sensitivity to Ischemic Injury in Rodents

Cardiovascular disease (CVD) is the largest cause of mortality worldwide, and stress is a significant contributor to the development of CVD. The relationship between acute and chronic stress and CVD is well evidenced. Acute stress can lead to arrhythmias and ischemic injury. However, recent evidence in rodent models suggests that acute stress can decrease sensitivity to myocardial ischemia-reperfusion injury (IRI). Conversely, chronic stress is arrhythmogenic and increases sensitivity to myocardial IRI. Few studies have examined the impact of validated animal models of stress-related psychological disorders on the ischemic heart. This review examines the work that has been completed using rat models to study the effects of stress on myocardial sensitivity to ischemic injury. Utilization of animal models of stress-related psychological disorders is critical in the prevention and treatment of cardiovascular disorders in patients experiencing stress-related psychiatric conditions.

Emotional, neurohormonal, and hemodynamic responses to mental stress in Tako-Tsubo cardiomyopathy

Tako-Tsubo cardiomyopathy (TTC) is characterized by apical ballooning of the left ventricle and symptoms and signs mimicking acute myocardial infarction. The high catecholamine levels in the acute phase of TTC and common emotional triggers suggest a dysregulated stress response system. This study examined whether patients with TTC show exaggerated emotional, neurohormonal, and hemodynamic responses to mental stress. Patients with TTC (n = 18; mean age 68.3 ± 11.7, 78% women) and 2 comparison groups (healthy controls, n = 19; mean age 60.0 ± 7.6, 68% women; chronic heart failure, n = 19; mean age 68.8 ± 10.1, 68% women) performed a structured mental stress task (anger recall and mental arithmetic) and low-grade exercise with repeated assessments of negative emotions, neurohormones (catecholamines: norepinephrine, epinephrine, dopamine, hypothalamic-pituitary-adrenal axis hormones: adrenocorticotropic hormone [ACTH], cortisol), echocardiography, blood pressure, and heart rate. TTC was associated with higher norepinephrine (520.7 ± 125.5 vs 407.9 ± 155.3 pg/ml, p = 0.021) and dopamine (16.2 ± 10.3 vs 10.3 ± 3.9 pg/ml, p = 0.027) levels during mental stress and relatively low emotional arousal (p <0.05) compared with healthy controls. During exercise, norepinephrine (511.3 ± 167.1 vs 394.4 ± 124.3 pg/ml, p = 0.037) and dopamine (17.3 ± 10.0 vs 10.8 ± 4.1 pg/ml, p = 0.017) levels were also significantly higher in patients with TTC compared with healthy controls. In conclusion, catecholamine levels during mental stress and exercise were elevated in TTC compared with healthy controls. No evidence was found for a dysregulated hypothalamic-pituitary-adrenal axis or hemodynamic responses. Patients with TTC showed blunted emotional arousal to mental stress. This study suggests that catecholamine hyper-reactivity and not emotional hyper-reactivity to stress is likely to play a role in myocardial vulnerability in TTC.

A brief review and clinical application of heart rate variability biofeedback in sports, exercise, and rehabilitation medicine

CONTEXT

An important component of the effective management of chronic noncommunicable disease is the assessment and management of psychosocial stress. The measurement and modulation of heart rate variability (HRV) may be valuable in this regard.

OBJECTIVE

To describe the measurement and physiological control of HRV; to describe the impact of psychosocial stress on cardiovascular disease, metabolic syndrome, and chronic respiratory disease, and the relationship between these diseases and changes in HRV; and to describe the influence of biofeedback and exercise on HRV and the use of HRV biofeedback in the management of chronic disease.

DATA SOURCES AND STUDY SELECTION

The PubMed, Medline, and Embase databases were searched (up to August 2013). Additional articles were obtained from the reference lists of relevant articles and reviews. Articles were individually selected for further review based on the quality and focus of the study, and the population studied.

RESULTS

Heart rate variability is reduced in stress and in many chronic diseases, and may even predict the development and prognosis of some diseases. Heart rate variability can be increased with both exercise and biofeedback. Although the research on the effect of exercise is conflicting, there is evidence that aerobic training may increase HRV and cardiac vagal tone both in healthy individuals and in patients with disease. Heart rate variability biofeedback is also an effective method of increasing HRV and cardiac vagal tone, and has been shown to decrease stress and reduce the morbidity and mortality of disease.

CONCLUSION

The assessment and management of psychosocial stress is a challenging but important component of effective comprehensive lifestyle interventions for the management of noncommunicable disease. It is, therefore, important for the sports and exercise physician to have an understanding of the therapeutic use of HRV modulation, both in the reduction of stress and in the management of chronic disease.

Current perspective on mental stress-induced myocardial ischemia

Mental stress and emotional arousal can act as triggers of myocardial infarction and other adverse cardiovascular outcomes. This editorial presents an overview of the research on mental stress-induced myocardial ischemia (MSIMI) and comments on two investigations examining MSIMI published in this journal. These studies confirm that MSIMI is frequently observed in patients with coronary artery disease and that characteristics, such as being a woman younger than 50 years and depression, may increase the relative risk of MSIMI. The method used for determining MSIMI (i.e., assessing cardiac function as determined by echocardiography versus measurement of myocardial perfusion using single-photon emission computed tomography), as well as the nature of the mental stress protocols (i.e., one stress task versus several repeated tasks), may have important effects on the findings of MSIMI research and on their interpretation. An overview of clinical characteristics of MSIMI is presented, and the article concludes with possible directions for future MSIMI research.

Lower Framingham risk score and the absence of hypertension are associated with the morning peak in the circadian variation of ST-elevation myocardial infarction onset

There are few studies analyzing the influences of coronary risk factors on the circadian variation of ST-elevation myocardial infarction (STEMI). Between 2008 and 2011, 293 patients were admitted to Miyazaki Prefectural Nobeoka Hospital with STEMI. The onset time of STEMI was identified in 280 patients (age, 70.5±11.7 years; male subjects, 68%; hypertension (HT), 80%; diabetes mellitus, 28%; current smoking (cSM), 33%; Framingham risk score (FRS), 8.77±3.28). The day was divided into six 4-h periods, with the morning peak between 0800 and 1200 hours. The frequency of HT was significantly lower in the morning incidence group than in the nighttime incidence group. Multivariate logistic regression analysis revealed that the prevalence of HT was the only independent variable associated with the morning peak of STEMI (odds ratio (OR), 0.43; 95% confidence interval (95% CI), 0.23-0.83; P=0.01) and that cSM was significantly associated with the nighttime peak of STEMI (OR, 1.96; 95% CI, 1.01-3.80; P=0.04). A comprehensive evaluation using the FRS showed that the FRS was significantly lower in the morning incidence group than in the nighttime incidence group and the other time incidence group (7.95±3.47 vs. 9.14±2.89 vs. 9.06±3.25, P<0.01), and that having a lower FRS was associated with the morning peak of STEMI (OR, 1.12; 95% CI, 1.02-1.21; P=0.01). A lower FRS and non-HT status are associated with the morning peak in the circadian variation of STEMI onset. The morning incidence of STEMI might be affected by pathogenic factors other than the classic coronary risk factors.

Melatonin attenuates the skin sympathetic nerve response to mental stress

Melatonin attenuates muscle sympathetic nerve responses to sympathoexcitatory stimuli, but it is unknown whether melatonin similarly attenuates reflex changes in skin sympathetic nerve activity (SSNA). In this double-blind, placebo-controlled, crossover study, we tested the hypothesis that melatonin (3 mg) would attenuate the SSNA response to mental stress (mental arithmetic). Twelve healthy subjects underwent experimental testing on two separate days. Three minutes of mental stress occurred before and 45 min after ingestion of melatonin (3 mg) or placebo. Skin temperature was maintained at 34°C. Reflex increases in SSNA (peroneal nerve), mean arterial pressure, and heart rate (HR) to mental stress before and after melatonin were determined. Melatonin lowered HR (pre, 66 ± 3 beats/min; and post, 62 ± 3 beats/min, P = 0.046) and SSNA (pre, 14,282 ± 3,706 arbitrary units; and post, 9,571 ± 2,609 arbitrary units, P = 0.034) at rest. In response to mental stress, SSNA increases were significantly attenuated following melatonin ingestion (second minute, 114 ± 30 vs. 74 ± 14%; and third minute, 111 ± 29 vs. 54 ± 12%, both P < 0.05). The mean arterial pressure increase to mental stress was blunted in the third minute (20 ± 2 vs. 17 ± 2 mmHg, P = 0.032), and the HR increase was blunted in the first minute (33 ± 3 vs. 29 ± 3 beats/min, P = 0.034) after melatonin. In summary, exogenous melatonin attenuates the SSNA response to mental stress.

Relation of outbursts of anger and risk of acute myocardial infarction

The aim of the present study was to explore the association between outbursts of anger and acute myocardial infarction (AMI) risk. Outbursts of anger are associated with an abrupt increase in cardiovascular events; however, it remains unknown whether greater levels of anger intensity are associated with greater levels of AMI risk or whether potentially modifiable factors can mitigate the short-term risk of AMI. We conducted a case-crossover analysis of 3,886 participants from the multicenter Determinants of Myocardial Infarction Onset Study, who were interviewed during the index hospitalization for AMI from 1989 to 1996. We compared the observed number and intensity of anger outbursts in the 2 hours preceding AMI symptom onset with its expected frequency according to each patient's control information, defined as the number of anger outbursts in the previous year. Of the 3,886 participants in the Determinants of Myocardial Infarction Onset Study, 1,484 (38%) reported outbursts of anger in the previous year. The incidence rate of AMI onset was elevated 2.43-fold (95% confidence interval 2.01 to 2.90) within 2 hours of an outburst of anger. The association was consistently stronger with increasing anger intensities (p trend <0.001). In conclusion, the risk of experiencing AMI was more than twofold greater after outbursts of anger compared with at other times, and greater intensities of anger were associated with greater relative risks. Compared with nonusers, regular β-blocker users had a lower susceptibility to heart attacks triggered by anger, suggesting that some drugs might lower the risk from each anger episode.

The impact of acute mental stress on vascular endothelial function: evidence, mechanisms and importance

Cardiovascular disease is a principle cause of morbidity and mortality worldwide, and it has a complex etiology that involves lifestyle factors such as psychosocial stress. Recent evidence suggests that temporary impairments in vascular endothelial cell function may contribute to the relationship between stress and cardiovascular disease. Indeed, impaired endothelial function has been observed to occur transiently (lasting up to 1.5h) following mental stress, and such periods of impairment could accumulate to become clinically relevant over the long term. The finding of acute stress induced endothelial dysfunction is not universal however, and both physiological (e.g. sympathetic nervous system and hypothalamic-pituitary-adrenal axis reactivity), and methodological factors contribute to the conflicting results. A clear understanding of the interaction between stress response activation and endothelial function is critical to elucidating the complexities of the relationship between psychosocial stress and cardiovascular disease. Therefore, the purpose of this review is: 1) to briefly describe the importance of vascular endothelial function and how it is assessed, 2) to review the literature investigating the impact of acute mental stress on endothelial function in humans, identifying factors that may explain contradictory results, and 3) to summarize our current understanding of the mechanisms that may mediate an acute mental stress-endothelial function interaction.

Central nervous system involvement in the autonomic responses to psychological distress

Psychological distress can trigger acute coronary syndromes and sudden cardiac death in vulnerable patients. The primary pathophysiological mechanism that plays a role in stress-induced cardiac events involves the autonomic nervous system, particularly disproportional sympathetic activation and parasympathetic withdrawal. This article describes the relation between psychological distress and autonomic nervous system function, with a focus on subsequent adverse cardiovascular outcomes. The role of the central nervous system in these associations is addressed, and a systematic review is presented of studies examining the association between stress-induced central nervous system responses measured by neuroimaging techniques and autonomic nervous system activation. Results of the systematic review indicate that the primary brain areas involved in the autonomic component of the brain-heart association are the insula, medial prefrontal cortex, and cerebellum (based on 121 participants across three studies that fitted the inclusion criteria). Other areas involved in stress-induced autonomic modulation are the (anterior) cingulate cortex, parietal cortex, somatomotor cortex/precentral gyrus, and temporal cortex. The interaction between central and autonomic nervous system responses may have implications for further investigations of the brain-heart associations and mechanisms by which acute and chronic psychological distress increase the risk of myocardial infarction, cardiac arrhythmias, and sudden cardiac death.

Role of central oxytocin in stress-induced cardioprotection in ischemic-reperfused heart model

BACKGROUND AND PURPOSE

There is growing evidence that stress contributes to cardiovascular disease and triggers the release of oxytocin. Moreover previous studies confirmed oxytocin mimics the protection associated with ischemic preconditioning. The present study was aimed to assess the possible cardioprotective effects of the centrally released oxytocin in response to stress and intracerebroventricular (i.c.v.) administration of exogenous oxytocin in ischemic-reperfused isolated rat heart.

METHODS AND SUBJECTS

Rats were divided in two main groups and all of them were subjected to i.c.v. infusion of vehicle or drugs: unstressed rats [control: vehicle, oxytocin (OT; 100 ng/5 μl), atosiban (ATO; 4.3 μg/5 μl) as oxytocin antagonist, ATO+OT] and stressed rats [St: stress, OT+St, ATO+St]. After anesthesia, hearts were isolated and subjected to 30 min regional ischemia and 60 min reperfusion (IR). Acute stress protocol included swimming for 10 min before anesthesia. Myocardial function, infarct size, coronary flow, ventricular arrhythmia, and biochemical parameters such as creatine kinase and lactate dehydrogenase were measured. Ischemia-induced ventricular arrhythmias were counted during the occlusion period.

RESULTS

The plasma levels of oxytocin and corticosterone were significantly elevated by stress. Unexpectedly hearts of stressed rats showed a marked depression of IR injury compared to control group. I.c.v. infusion of oxytocin mimicked the cardioprotective effects of stress, yet did not elevate plasma oxytocin level. The protective effects of both stress and i.c.v. oxytocin were blocked by i.c.v. oxytocin antagonist.

CONCLUSIONS

These findings suggest that i.c.v. infusion of exogenous oxytocin and centrally released endogenous oxytocin in response to stress could play a role in induction of a preconditioning effect in ischemic-reperfused rat heart via brain receptors.

Mental stress-induced ischemia in patients with coronary artery disease: echocardiographic characteristics and relation to exercise-induced ischemia

OBJECTIVE

The aims of this study were to investigate the incidence and parameters associated with myocardial ischemia during mental stress (MS) as measured by echocardiography and to evaluate the relation between MS-induced and exercise-induced myocardial ischemia.

METHODS

Study participants were 79 patients (63 men; mean [M] [standard deviation {SD}] age = 52 [8] years) with angiographically confirmed coronary artery disease and previous positive exercise test result. The MS protocol consisted of mental arithmetic and anger recall task. The patients performed a treadmill exercise test 15 to 20 minutes after the MS task. Data of post-MS exercise were compared with previous exercise stress test results.

RESULTS

The frequency of echocardiographic abnormalities was 35% in response to the mental arithmetic task, compared with 61% with anger recall and 96% with exercise (p < .001, exercise versus MS). Electrocardiogram abnormalities and chest pain were substantially less common during MS than were echocardiographic abnormalities. Independent predictors of MS-induced myocardial ischemia were: wall motion score index at rest (p = .02), peak systolic blood pressure (p = .005), and increase in rate-pressure product (p = .004) during MS. The duration of exercise stress test was significantly shorter (p < .001) when MS preceded the exercise and in the case of earlier exercise (M [SD] = 4.4 [1.9] versus 6.7 [2.2] minutes for patients positive on MS and 5.7 [1.9] versus 8.0 [2.3] minutes for patients negative on MS).

CONCLUSIONS

Echocardiography can be successfully used to document myocardial ischemia induced by MS. MS-induced ischemia was associated with an increase in hemodynamic parameters during MS and worse function of the left ventricle. MS may shorten the duration of subsequent exercise stress testing and can potentiate exercise-induced ischemia in susceptible patients with coronary artery disease.

The effect of acute stress exposure on ischemia and reperfusion injury in rat heart: role of oxytocin

Previous studies showed the protective effects of oxytocin (OT) on myocardial injury in ischemic and reperfused rat heart. Moreover, exposure to various stressors not only evokes sudden cardiovascular effects but also triggers the release of OT in the rat. The present study was aimed to evaluate the possible cardioprotective effects of endogenous OT released in response to stress (St), and effects of administration of exogenous OT on the ischemic-reperfused isolated heart of rats previously exposed to St. Wistar rats were divided into six groups: ischemia/reperfusion (IR); St: rats exposed to swim St for 10 min before anesthesia; St+atosiban (ATO): an OT receptor antagonist, was administered (1.5 mg/kg i.p.) prior to St; St+OT: OT was administered (0.03 mg/kg i.p.) prior to St; OT: OT was administrated prior to anesthesia; ATO was given prior to anesthesia. Isolated hearts were perfused with Krebs buffer solution by the Langendorff method and subjected to 30 min of regional ischemia followed by 60 min of reperfusion. The infarct size (IS) and creatine kinase MB isoenzyme (CK-MB) and lactate dehydrogenase (LDH) in coronary effluent were measured. Hemodynamic parameters were recorded throughout the experiment. The plasma concentrations of OT and corticosterone were significantly increased by St. Unexpectedly St decreased IR injury compared with the IR alone group. OT administration significantly inhibited myocardial injury, and administration of ATO with St abolished recovery of the rate pressure product, and increased IS and levels of CK-MB and LDH. These findings indicate that activation of cardiac OT receptors by OT released in response to St may participate in cardioprotection and inhibition of myocardial IR injury.

Effects of chronic mental stress and atherogenic diet on the immune inflammatory environment in mouse aorta

Inflammation and stress are regarded as two important atherogenic factors. Because stress can affect leukocyte distribution, we hypothesized that stress-mediated leukocyte extravasation can modify the inflammatory environment of the arterial wall possibly contributing to atherogenesis. To test this hypothesis we evaluated the inflammatory environment of the aorta in C57Bl/6 mice subjected to 3 and 12 months of chronic stress and compared it to age matched non-stressed animals. Experiments were carried out in mice fed regular chow or atherogenic diets. Both treatments increased the expression of vascular and leukocyte adhesion molecules and leukocyte accumulation. At 3 months, stress but not an atherogenic diet elevated the number of CD4 cells, CD8 cells, macrophages, dendritic cells and neutrophils. These changes were associated with elevation of transcripts for ICAM-1 and VCAM-1, E-selectin and neuropeptide Y. At 12 months, stress or high cholesterol acted similarly to elevate the number of CD8 and macrophages, and synergistically on the number of all cell types investigated. At this time-point, strong synergism was also observed on the level of E-selectin and NPY in the aorta, but not in the circulation. Despite these effects, histological and morphological alterations of the arterial wall were severe in the atherogenic diet, but not in the stress groups. Thus, although stress and an atherogenic diet may both affect leukocyte accumulation in the aorta, they may contribute differently to atherogenesis.

[Psychiatric and behavioral aspects of cardiovascular disease: epidemiology, mechanisms, and treatment]

Psychosocial and behavioral factors, including mood (depression, anxiety, anger, and stress), personality (Type A, Type D, and hostility), and social support, are associated with both the development and progression of cardiovascular disease. "Negative" emotions have been associated with increased rates of cardiovascular death and recurrent cardiac events, although the mechanisms responsible for this association remain unclear. A number of pathophysiological mechanisms have been proposed to explain these relationships, including hypothalamic-pituitary-adrenal axis dysregulation, platelet activation, and inflammation. Behavioral factors also have been implicated, such as nonadherence to prescribed medical therapies and physical inactivity. Several randomized trials of patients with cardiovascular disease have examined the impact of pharmacologic and behavioral treatments on hard cardiovascular disease events as well as on cardiovascular disease biomarkers of risk. Although psychological treatments generally have been shown to improve quality of life and psychological functioning among cardiac patients, the benefit of psychological interventions with respect to improving clinical outcomes has not been conclusively demonstrated.

[Psychiatric and behavioral aspects of cardiovascular disease: epidemiology, mechanisms, and treatment]

Psychosocial and behavioral factors, including mood (depression, anxiety, anger, and stress), personality (Type A, Type D, and hostility), and social support, are associated with both the development and progression of cardiovascular disease. "Negative" emotions have been associated with increased rates of cardiovascular death and recurrent cardiac events, although the mechanisms responsible for this association remain unclear. A number of pathophysiological mechanisms have been proposed to explain these relationships, including hypothalamic-pituitary-adrenal axis dysregulation, platelet activation, and inflammation. Behavioral factors also have been implicated, such as nonadherence to prescribed medical therapies and physical inactivity. Several randomized trials of patients with cardiovascular disease have examined the impact of pharmacologic and behavioral treatments on hard cardiovascular disease events as well as on cardiovascular disease biomarkers of risk. Although psychological treatments generally have been shown to improve quality of life and psychological functioning among cardiac patients, the benefit of psychological interventions with respect to improving clinical outcomes has not been conclusively demonstrated.

Distress in the radiology waiting room

PURPOSE

To assess the level of distress in women awaiting radiologic procedures.

MATERIALS AND METHODS

In this institutional review board-approved and HIPAA-compliant study, 214 women between 18 and 86 (mean, 47.9) years of age completed the State Trait Anxiety Inventory (STAI), Impact of Events Scale (IES), Center for Epidemiologic Studies Depression Scale (CES-D), and Perceived Stress Scale (PSS) immediately prior to their procedures. One hundred twelve women awaited breast biopsy; 42, hepatic chemoembolization for cancer; and 60, uterine fibroid embolization. Data were analyzed with multivariate analysis of variance and post hoc Tukey tests. Results are reported as means and 95% confidence intervals (CIs).

RESULTS

All three patient groups experienced abnormally high mean PSS, IES, and CES-D scores, but only the breast biopsy group had highly abnormal anxiety levels. Breast biopsy patients had a significantly higher mean STAI score of 48 (95% CI: 45, 50) than did women awaiting hepatic chemoembolization (mean score, 26; 95% CI: 22, 29; P < .001) and fibroid embolization (mean score, 24; 95% CI: 21, 27; P < .001). IES ratings did not differ significantly among the groups, with a mean score of 26 (95% CI: 23, 29) for breast biopsy patients, 23 (95% CI: 18, 28) for hepatic chemoembolization patients, and 23 (95% CI: 18, 27) for fibroid embolization patients. The CES-D score did not differ significantly among breast biopsy (mean score, 15; 95% CI: 13, 17), hepatic chemoembolization (mean score, 14; 95% CI: 11, 18), and fibroid embolization (mean score, 12; 95% CI: 9, 15) patients. PSS ratings of breast biopsy patients were significantly higher (mean score, 18; 95% CI: 16, 19) than those of hepatic chemoembolization patients (mean, 15; 95% CI: 13, 17; P < .01), but they were not significantly different from those of women awaiting fibroid embolization (mean, 16; 95% CI: 14, 18; P = .23).

CONCLUSION

Uncertainty of diagnosis can be associated with greater stress than is awaiting more invasive and potentially risky treatment.

Autonomic nervous system reactivity to positive and negative mood induction: the role of acute psychological responses and frontal electrocortical activity

The differential effects of positive versus negative emotions on autonomic nervous system activity are insufficiently understood. This study examined the role of acute mood responses and central nervous system activity on heart rate variability (HRV) using 5-min event recall tasks (happiness and anger recall) and a 5-min Stroop Color Word Test (SCWT) in 20 healthy individuals (mean age 25 ± 4 years, 55% female). HRV was measured in high frequency (HF) and low frequency (LF) domains, and frontal brain activity using electroencephalography (EEG) in the alpha frequency band in F3 and F4. Happiness Recall resulted in increased LF-HRV (p = 0.005) but not HF-HRV (p=0.71). Anger Recall did not change HRV (p-values > 0.10). The SCWT produced decreases in HF-HRV (p = 0.001) as well as LF-HRV (p = 0.001). The magnitude of feeling "happy" during Happiness Recall was positively correlated with ΔHF-HRV (p = 0.050), whereas an incongruent mood state ("frustrated") was associated with smaller ΔHF-HRV (p = 0.070). Associations between frontal EEG activation and HRV responses were mostly non-significant, except for increased right frontal activation during Happiness Recall which was associated with a decrease in LF/HF ratio (p = 0.009). It is concluded that positive and negative mood induction result in differential HRV responses, which is related to both task valence and the intensity of task-induced emotions.

Circadian, day-of-week, and age patterns of the occurrence of acute coronary syndrome in Beijing's emergency medical services system

Background

Previous in-hospital studies suggest that there are significant circadian rhythms associated with the incidence of acute coronary syndromes (ACSs). No study to date has examined the presentation of ACS in the prehospital setting. Our goal was to examine circadian, day-of-week, and age patterns of occurrence in ACS in a large, urban emergency medical services (EMS) system.

Methods

We retrospectively reviewed the electronic prehospital medical records from the Beijing's EMS system spanning August 1, 2005, to July 31, 2007. Data were analyzed by hour of the day and day of the week. χ² tests were performed to compare the difference.

Results

Seven thousand thirty-two cases of ACS were identified by the EMS system physicians during the 2-year study period, including 536 cases of acute myocardial infarction. A significant variation of circadian distribution of ACS was observed in both 24-hour (P < .001) and 2-hour (P < .001) interval time course. Two peaks were observed in the morning from 0800 to 1000 and approaching midnight from 2200 to 2400. Increases of 50% and 60.8% in the morning and evening peaks were found, respectively, when compared with the early morning baseline (nadir). No significant difference was found among the accumulated cases in 2 years on each day in a week (P = .203).

Conclusions

Our study shows that, in the Beijing metropolitan area, the presentation of ACS has significant circadian rhythm characterized by 2 peaks within 24 hours, the morning peak is 0800 to 1000, and the late evening peak is 2200 to 2400. No significant weekly rhythm was observed in the present study.

Homicide by fright: the intersection of cardiology and criminal law

The prevailing lay wisdom associates emotional stress with sudden death, and recent medical reports have linked massive catecholamine surges with demonstrable cardiac dysfunction that can be either reversible or fatal. This association does not strictly prove causality, and the question remains open for additional scientific investigation. From the legal viewpoint, however, the issue has been resolved, and case law clearly holds that sudden emotional stress can cause death. More significantly, case law also holds that if the sudden emotional stress is caused by criminal conduct, the resulting death of a victim of the criminal conduct can be prosecuted as homicide. Cardiologists are often called to testify in such circumstances. In the present study, we have reviewed 8 legal cases that are the basis of current opinions in these matters. These legal principles can be summarized as follows: emotional stress is sufficient, and physical abuse is not required for conviction; a time-lapse between the induction of emotional stress and death does not necessarily mitigate the charge of homicide; the criminal act must be the proximate cause of the victim's death; however, the accused does not always need to be physically present to commit the crime. In conclusion, although the pathophysiology of sudden death associated with massive emotional stress has not been fully elucidated from a scientific viewpoint, in the legal system, the association can be causative and can be the basis for a criminal prosecution. Cardiologists may be called on to provide expert opinions in the prosecution of these cases.

Seasonal variation in blood concentrations of interleukin-6, adrenocorticotrophic hormone, metabolites of catecholamine and cortisol in healthy volunteers

We investigated seasonal changes in blood concentrations of interleukin-6 (IL-6), adrenocorticotrophic hormone (ACTH), metabolites of catecholamine (VMA, HVA, and 5-HIAA) and cortisol in humans. Eight volunteers were investigated at four times during the year (February, May, August and October) at latitude 35 degrees N. The mean ambient temperature at the collection periods was higher in the order of summer > autumn approximately spring > winter. Changes in mood were also monitored by a profile of mood states (POMS) questionnaire. The concentration of IL-6 was significantly higher in winter and summer than in spring and autumn. The concentrations of ACTH, HVA and VMA were significantly higher in summer. No seasonal variation was detected in cortisol. There were significant differences among the seasons in subscale tension and anger in the POMS questionnaire; the tension subscale showed significant differences between spring and autumn, with a higher score in spring. The results demonstrate that Il-6, ACTH, HVA and VMA exhibit statistically significant seasonal rhythms, which might have important diagnostic and therapeutic implications.

Effect of oral melatonin on the procoagulant response to acute psychosocial stress in healthy men: a randomized placebo-controlled study

Acute mental stress is a potent trigger of acute coronary syndromes. Catecholamine-induced hypercoagulability with acute stress contributes to thrombus growth after coronary plaque rupture. Melatonin may diminish catecholamine activity. We hypothesized that melatonin mitigates the acute procoagulant stress response and that this effect is accompanied by a decrease in the stress-induced catecholamine surge. Forty-five healthy young men received a single oral dose of either 3 mg melatonin (n = 24) or placebo medication (n = 21). One hour thereafter, they underwent a standardized short-term psychosocial stressor. Plasma levels of clotting factor VII activity (FVII:C), FVIII:C, fibrinogen, D-dimer, and catecholamines were measured at rest, immediately after stress, and 20 min and 60 min post-stress. The integrated change in D-dimer levels from rest to 60 min post-stress differed between medication groups controlling for demographic and metabolic factors (P = 0.047, eta(p)(2) = 0.195). Compared with the melatonin group, the placebo group showed a greater increase in absolute D-dimer levels from rest to immediately post-stress (P = 0.13; eta(p)(2) = 0.060) and significant recovery of D-dimer levels from immediately post-stress to 60 min thereafter (P = 0.007; eta(p)(2) = 0.174). Stress-induced changes in FVII:C, FVIII:C, fibrinogen, and catecholamines did not significantly differ between groups. Oral melatonin attenuated the stress-induced elevation in the sensitive coagulation activation marker D-dimer without affecting catecholamine activity. The finding provides preliminary support for a protective effect of melatonin in reducing the atherothrombotic risk with acute mental stress.

Effects of acute mental stress and exercise on inflammatory markers in patients with coronary artery disease and healthy controls

Physical and mental stressors result in increased inflammation markers in populations free of coronary artery disease (CAD). However, inflammatory responses to mental and exercise challenges have not been established in patients with CAD. This study investigated the responses of inflammatory markers, including C-reactive protein (CRP), interleukin-6 (IL-6), and soluble intercellular adhesion molecule-1, in patients with CAD after successful elective percutaneous coronary intervention (n = 36, 59 +/- 8 years of age, 33% women) and healthy controls without a history of CAD (n = 28, 54 +/- 10 years of age, 36% women). Increases in inflammatory markers were examined in response to mental challenge tasks (anger recall and mental arithmetic) and treadmill exercise. Stress echocardiography was used to rule out stress-induced ischemia as a possible confounding factor. Results showed that CRP increased significantly to mental challenge and exercise (p values <0.01), and CRP responses were higher in patients with CAD than in controls (change in mental arithmetic 0.19 +/- 0.11 vs 0.01 +/- 0.03 mg/L, p = 0.003; change in exercise 0.57 +/- 0.11 vs 0.08 +/- 0.0.03 mg/L, p = 0.001). Increased norepinephrine responses were related to larger CRP and IL-6 increases to mental challenge tasks (p values <0.05). Exercise elicited increased CRP, IL-6, and soluble intercellular adhesion molecule-1 levels (p values <0.01), and these responses were larger than with mental challenge tasks (p values <0.05). In conclusion, mental stress and exercise induce increased levels of inflammatory markers in patients with CAD. These stress-induced increases are larger than in healthy subjects, occur in the absence of myocardial ischemia, and are related to the neurohormonal stress response.

Interleukin-18 and stress

Interleukin-18 (IL-18) is a pro-inflammatory cytokine believed to play a role in a variety of conditions and diseases including infections, autoimmunity, cancer, diabetes and atherosclerosis. IL-18 is also a possible contributor to the sickness syndrome by inducing anorexia and sleep. Originally recognized to be produced by cells of the immune system, IL-18 is also found in endocrine tissues, including the adrenal and the pituitary glands, and in the central nervous system where it is produced by microglial and ependymal cells as well as by neurons of the medial habenular nucleus. IL-18 is produced constitutively and its levels can increase during infection but also during stress in the absence of an exogenous stimulus. IL-18 levels are elevated by activation of the hypothalamic-pituitary-adrenal (HPA) axis in a tissue specific way via differential promoter and splicing usage, and may be down-regulated by the activation of the para-sympathetic system. This suggested the possibility that IL-18 may participate in the regulation of the HPA axis or that it may have a role in mediating the CNS dependent effects on the susceptibility to or the progression of diseases. This review summarizes the evidence linking stress and IL-18 and discusses the possible implication of the neuro-immuno-modulatory action of IL-18.

A bio-psycho-socio-molecular approach to pain and stress management

Stress and trauma are interconnected with the experience of pain. This connection is due to a physiological coupling of underlying molecular autoregulatory mechanisms, as well as phenomenological similarities. Nonpharmaceutical therapeutic approaches such as the relaxation response, a process that supports physiological stress reduction and decreases the negative mental and physical effects of stress, also facilitate pain relief, again demonstrating physiological commonalities. These behavioral approaches have a critical impact on molecular patterns of autoregulation, leading to the assumption of a bio-psycho-socio-molecular model of autoregulation, including stress and pain. Thus, molecules and behavior may be seen as two sides of the same problem in pain and stress relief.

Delayed increase in LDL cholesterol following pentagastrin-induced panic attacks

OBJECTIVE

Panic disorder (PD) has been associated with an increased risk for cardiovascular (CV) morbidity and mortality. There are inconsistent reports of increased low-density lipoprotein cholesterol (LDL-C) in patients with PD. Studies have reported a correlation between cholesterol levels and the intensity and frequency of panic attacks (PAs), suggesting that an elevation in cholesterol could be due to physiological and neurochemical changes that occur during and after a PA. The objective of our study was to show that the occurrence of a PA is associated with an increase in LDL-C.

MATERIALS AND METHODS

We used a double-blind, placebo-controlled crossover design with randomized injections of placebo and pentagastrin in 18 patients with PD (11 men, 7 women) and 33 healthy-control subjects (24 men, 9 women).

RESULTS

Pentagastrin-induced PAs were associated with a statistically significant 10.4% delayed (24 h) increase in LDL-C levels in male subjects. Such an effect was not observed in female subjects.

CONCLUSION

LDL-C levels are directly affected by the occurrence of a PA in males. These findings, in association with previous reports of increased cholesterol levels in PD patients, suggest that a chronic increase in LDL-C as a result of frequent PAs may be one of the mechanisms that contributes, at least in male patients, to previously reported increased CV risk in patients with PD. The gender difference and the temporal association between PAs and increased LDL-C may explain the inconsistency in the findings of previous investigations of cholesterol levels in PD patients.

Interactions among higher trait anxiety, sympathetic activity, and endothelial function in the elderly

Negative psychological characteristics have been recognized as independent risk factors of cardiovascular disease (CVD). The purpose of this study was to evaluate the influence of depression and anxiety on cardiac autonomic function and endothelial function in healthy elderly subjects. Forty-six healthy elderly volunteers (mean age 60.8 years) were enrolled in this study. Cardiac autonomic function was assessed by spectral analysis of heart rate variability (HRV) with the head-up tilt test. Brachial artery endothelium-dependent flow-mediated dilation (FMD) was measured using high-resolution ultrasound. A significant positive correlation was observed between the State and Trait Anxiety Inventory (STAI)-trait score as a parameter of anxiety and HRV sympathetic modulation in the supine position (baseline), and a significant negative correlation between this score and the head-up-induced HRV sympathetic response from the baseline. The STAI-trait score also showed a significant negative correlation with the percent change of FMD (%FMD). Analysis using structural equation modeling showed that higher trait anxiety reduced %FMD via abnormalities of sympathetic activity. On the other hand, psychometric parameters of depression were not associated with any HRV component or %FMD. These results suggest that there are specific interactions among higher trait anxiety, abnormalities of sympathetic activity, and endothelial dysfunction. This finding may be useful in clarifying the pathophysiological mechanism by which anxiety is associated with increased risks for atherosclerosis and CVD.