Left ventricular, peripheral vascular, and neurohumoral responses to mental stress in normal middle-aged men and women. Reference Group for the Psychophysiological Investigations of Myocardial Ischemia (PIMI) Study

The prognostic study of mental stress-induced myocardial ischemia in coronary revascularization patients with depression/anxiety: rationale and design

BACKGROUND

Mental stress-induced myocardial ischemia (MSIMI) frequently occurs in patients with coronary artery disease (CAD), and is even more common in patients with co-occurring CAD and depression/anxiety. MSIMI appears to be a poor prognostic factor for CAD, but existing data on depression/anxiety patients are limited.

METHODS

This cohort study will consecutively screen 2,647 CAD patients between 2023 and 2025. Included subjects will need to have received coronary revascularization and also have depression and/or anxiety at baseline. This study will enroll 360 subjects who meet the criteria. Two mental stress tests will be carried out in each patient at 1 month and 1 year timelines after coronary revascularization, using Stroop color word tests. MSIMI will be assessed by ^99 m-Tc-sestamibi myocardial perfusion imaging. The endothelial function will be assessed by EndoPAT. Furthermore, we will dynamically monitor patients' health and mental conditions every 3 months. The mean follow-up time will be 1 year. The primary endpoint is the major adverse cardiac events, a composite of all-cause death, cardiac death, myocardial infarction, stroke, or unplanned revascularization. Secondary endpoints will include overall health and mental conditions. The reproducibility of mental stress combined with myocardial perfusion for detecting MSIMI and comparisons between coronary stenosis and ischemic segments will also be included.

CONCLUSIONS

This cohort study will provide information on MSIMI outcomes in CAD patients who also have comorbid depression/anxiety after revascularization. In addition, understanding the long-term dynamics of MSIMI and the match between coronary stenosis and ischemia will provide insight into MSIMI mechanisms.

TRAIL REGISTRATION

ChiCTR2200055792, 2022.1.20, www.medresman.org.cn.

Pilot Study of the Effects of Paced Breathing on Measures of Convergent and Divergent Thinking

BACKGROUND

The ability of the autonomic nervous system's stress response to impair aspects of cognitive flexibility is known. However, the ability to modulate the sympathetic response and improve these cognitive impairments via nonpharmacological intervention, such as paced breathing (PB), requires further investigation.

OBJECTIVE

To better elucidate the effects of PB on cognition.

METHOD

We employed a PB protocol in a total of 52 healthy men and women and measured performance on convergent and divergent cognitive tasks, perceived stress, and physiological measures (eg, blood pressure, heart rate). Participants attended two experimental sessions consisting of either PB or normal breathing followed by cognitive assessments including convergent (compound remote associate, anagram) and divergent (alternate use, fluency) tasks. Experiment 2 consisted of more difficult versions of cognitive tasks compared with Experiment 1.

RESULTS

In Experiment 1, PB significantly reduced the female participants' systolic and diastolic blood pressure immediately after the breathing protocol without affecting their cognition. In Experiment 2, PB significantly reduced perceived stress immediately after the breathing protocol, regardless of sex. There was no effect on cognition in Experiment 2, but a correlation was observed between perceived stress change and anagram number solved change.

CONCLUSION

While PB modulates sympathetic activity in females, there was a lack of improvement in cognitive flexibility performance. At least for a single trial of PB, cognitive flexibility did not improve.

Mental Stress and Cardiovascular Health-Part I

Epidemiological studies have shown that a substantial proportion of acute coronary events occur in individuals who lack the traditional high-risk cardiovascular (CV) profile. Mental stress is an emerging risk and prognostic factor for coronary artery disease and stroke, independently of conventional risk factors. It is associated with an increased rate of CV events. Acute mental stress may develop as a result of anger, fear, or job strain, as well as consequence of earthquakes or hurricanes. Chronic stress may develop as a result of long-term or repetitive stress exposure, such as job-related stress, low socioeconomic status, financial problems, depression, and type A and type D personality. While the response to acute mental stress may result in acute coronary events, the relationship of chronic stress with increased risk of coronary artery disease (CAD) is mainly due to acceleration of atherosclerosis. Emotionally stressful stimuli are processed by a network of cortical and subcortical brain regions, including the prefrontal cortex, insula, amygdala, hypothalamus, and hippocampus. This system is involved in the interpretation of relevance of environmental stimuli, according to individual’s memory, past experience, and current context. The brain transduces the cognitive process of emotional stimuli into hemodynamic, neuroendocrine, and immune changes, called fight or flight response, through the autonomic nervous system and the hypothalamic–pituitary–adrenal axis. These changes may induce transient myocardial ischemia, defined as mental stress-induced myocardial ischemia (MSIMI) in patients with and without significant coronary obstruction. The clinical consequences may be angina, myocardial infarction, arrhythmias, and left ventricular dysfunction. Although MSIMI is associated with a substantial increase in CV mortality, it is usually underestimated because it arises without pain in most cases. MSIMI occurs at lower levels of cardiac work than exercise-induced ischemia, suggesting that the impairment of myocardial blood flow is mainly due to paradoxical coronary vasoconstriction and microvascular dysfunction.

Association between quality of life and mental stress-induced myocardial ischaemia in high-risk patients after coronary revascularization

Objective

We sought to determine the association between mental stress-induced myocardial ischaemia (MSIMI) and quality of life (QoL) in patients with coronary artery disease (CAD) after coronary revascularization.

Methods

This cohort study involved patients with high-risk MSIMI who received coronary revascularization between Dec 2018 and Dec 2019. Patients who screened positive for depression/anxiety were enrolled in this study. Mental stress was induced by the Stroop Colour and Word Test 1 month after coronary revascularization. All participants underwent single photon emission computed tomography (SPECT) scans at rest and under mental stress. MSIMI was defined as the presence of four abnormal SPECT phenomena. QoL was assessed using the Seattle Angina Questionnaire (SAQ) prior to treatment and 1 month after coronary revascularization.

Results

Of the 1845 consecutive patients who received coronary revascularization, 590 (31.9%) had depression/anxiety, and 205 agreed to accept the mental stress test. During the average observation period of 33 days, 105 (51.2%) patients exhibited MSIMI. All SAQ subscales showed significant improvement, except for QoL, in the MSIMI group. The QoL score was lower (− 0.2 ± 32.7 vs. 13.1 ± 29.9, P = 0.005), and the proportion of deterioration in QoL was higher (50.5% vs. 31.9%, P = 0.010) in the MSIMI group than in the non-MSIMI group. Those with a deterioration in QoL had approximately twice the rate of MSIMI than those with an improvement in QoL (unadjusted OR: 2.019, 95% CI 1.122–3.634, P = 0.026; adjusted OR: 1.968, 95% CI 1.083–3.578, P = 0.017).

Conclusion

Among patients with CAD who received coronary revascularization and had depression/anxiety, deterioration in QoL increased the likelihood of MSIMI. Hence, our results indicate that deterioration in QoL is a predictor of MSIMI.

Trail Registration ChiCTR2200055792, retrospectively registered, 2022.1.20, www.medresman.org.cn

The Foundational Role of Cardiovascular Imaging in the Characterization of Mental Stress-Induced Myocardial Ischemia in Patients with Coronary Artery Disease

PURPOSE OF REVIEW

Mental stress-provoked myocardial ischemia (MSIMI) is an ischemic phenomenon provoked by the experience of psychologically stressful circumstances. While MSIMI was initially identified 50 years ago during activities of daily living through the use of wearable Holter monitor, subsequent research utilized the technologies of cardiac imaging-ventriculography and myocardial perfusion-under controlled conditions to pursue an understanding of pathophysiology and prognosis. This work revealed that MSIMI occurs in almost half of patients with stable coronary artery disease (CAD) and is associated with cardiac events and early mortality. We provide a focused review of the instrumental role that cardiac imaging has played in elucidating how stress affects cardiac physiology and how emerging diagnostic techniques will allow for further research on stress-mediated changes in the coronary macro- and microvasculature.

RECENT FINDINGS

Observations about the cardiac response to mental stress diverge from underlying cornerstones of the traditional CAD paradigm which is based upon myocardial oxygen demand and the degree of epicardial coronary stenosis. Evidence from studies utilizing non-invasive and invasive studies of coronary perfusion indicates perturbations in the microvascular compartment in response to mental stress. Cardiovascular imaging enjoined with mental stress provocation may be a commanding tool to advance our understanding of non-obstructive CAD and the coronary microvasculature. This further understanding will facilitate incorporation of mental stress testing in the clinical care of patients with discrepant diagnostic work-up of CAD and in patients who experience anginal symptoms due to non-exertional and/or emotional triggers. Such algorithms will be crucial to identify treatment targets to modify the risk associated with mental stress-associated ischemia and adverse prognosis.

Effects of Psychological Stress on Vascular Physiology: Beyond the Current Imaging Signal

PURPOSE OF REVIEW

This review describes the effects of psychological stress on the physiology of the entire vascular system, from individual cellular components to macrovascular and microvascular responses, and highlights the importance of the vascular system in the context of current limitations in cardiac imaging for evaluation of the cardiovascular response to mental stress.

RECENT FINDINGS

The physiological responses that mediate vascular changes are based on evolutionary needs, but there is increasing evidence that the long-term consequences of psychological stress can precipitate the development and progression of cardiovascular disease (CVD). While there is an extensive body of literature describing localized physiological responses or overt cardiovascular manifestations, often framed within the organ-specific scope of cardiovascular imaging, there has not been a comprehensive description of the global vascular effects of psychological stress. Given the global nature of these processes, targeted cardiovascular imaging modalities may be insufficient. Here we approach the vascular response to mental stress systematically, describing the effects on the endothelium, vascular smooth muscle, and adventitia. We then address the mental stress effects on large vessels and the microvascular compartment, with a discussion of the role of microvascular resistance in the pathophysiology of mental stress-induced myocardial ischemia. Vascular responses to psychological stress involve complex physiological processes that are not fully characterized by routine cardiovascular imaging assessments. Future research incorporating standardized psychological assessments targeted toward vascular mechanisms of stress responses is required to guide the development of behavioral and therapeutic interventions.

A rare long-term undetected pheochromocytoma leading to Takotsubo syndrome in an older male patient: a case report

BACKGROUND

Takotsubo syndrome is an uncommon, acute, and reversible cardiomyopathy that occurs primarily in postmenopausal females. The clinical presentation of the syndrome resembles acute coronary syndrome, but coronary angiography reveals no obstructive coronary artery disease. Rarely, a catecholamine surge due to pheochromocytoma may induce Takotsubo syndrome. The clinical features of pheochromocytoma include paroxysmal hypertension, headache, palpitations, and profuse sweating. However, owing to the episodic, rather than continued, symptoms and signs of pheochromocytoma, its timely diagnosis poses a challenge for clinicians. Here, we report a rare case of long-term undetected pheochromocytoma leading to Takotsubo syndrome in an older male patient.

CASE PRESENTATION

A 70-year-old man presented with paroxysmal chest distress and chest pain. Examinations revealed acute coronary syndrome with normal coronary arteries, heart failure, reversible left ventricular regional wall motion abnormalities, labile blood pressure, a giant left adrenal mass, and extremely high levels of metanephrine and normetanephrine. Clinical manifestations, laboratory reports, and imaging findings suggested a diagnosis of Takotsubo syndrome caused by pheochromocytoma. Supportive therapy, administration of alpha- adrenergic receptor blockers, and left adrenal mass resection resolved the patient's symptoms. A histological examination confirmed the presence of pheochromocytoma. We reviewed his history of midbrain hemorrhage 6 years prior and found a mass in the left adrenal region by reviewing the computed tomography images of the lung that were also taken 6 years prior, on which the pheochromocytoma was evident.

CONCLUSIONS

Our case illustrates the importance of understanding the link between pheochromocytoma and Takotsubo syndrome. A diagnosis of pheochromocytoma-induced Takotsubo syndrome should be considered during the differential diagnosis of acute coronary syndrome, especially in patients with labile blood pressure and normal coronary angiography findings; meanwhile, assessments of catecholamines and its metabolites and abdominal computed tomography scan should be performed at the right time. Clinicians should also be alert to potential pheochromocytoma in patients with unexplained cerebral hemorrhage, even in the absence of symptoms of catecholamine excess.

Clinical factors affecting spot urine fractionated metanephrines in patients suspected pheochromocytoma/paraganglioma

Urinary measurement of fractionated metanephrines is one of the best available biochemical tests for the diagnosis of pheochromocytoma and paraganglioma; however, false-positive results remain an issue. In addition, despite their convenience, there is no evidence to suggest that spot urine samples should replace the standard 24-h urine collection method. The objective of this study is to elucidate clinical variables that may influence the levels of spot urine fractionated metanephrines and to examine their instability. The study is a retrospective review of prospectively collected data from 949 patients whose spot urine fractionated metanephrines were measured under suspicion of pheochromocytoma or paraganglioma at our institution from January 2011 to June 2017. The effects of clinical factors such as age, sex, renal function, and medications on the level of spot urine fractionated metanephrines were evaluated. Urinary fractionated metanephrines were significantly higher in female subjects. They correlated with age but not with estimated glomerular filtration rate (eGFR). A multivariate regression model for urinary fractionated metanephrine levels revealed that age, female sex, eGFR, and the presence of α1-blocker medication were significantly positively correlated with urinary metanephrine (M) levels. Age, female sex, eGFR, and presence of α1-blockers and antidepressant and antipsychotic medications positively correlated with urinary normetanephrine (NM). In addition, age, female sex, eGFR, and presence of α1-blockers and antidepressant and antipsychotic medications were positively correlated with urinary M + NM. In conclusion, sex, age, eGFR, and treatment with α1-blockers, antidepressants, and antipsychotics may affect the levels of urinary fractionated metanephrines. When assessing urinary fractionated metanephrines in patients with suspected PPGLs, we must consider these factors.

Cardiovascular Responses of Women with Fibromyalgia to a Laboratory Stressor: Does Post-traumatic Stress Disorder Comorbidity Matter?

OBJECTIVES

This study compared cardiovascular responses to a laboratory trauma-unrelated stressor of two groups of women diagnosed with fibromyalgia (FM), one of them with comorbid post-traumatic stress disorder (PTSD), with a group of healthy controls in order to detect the possible existence of differences linked to comorbidity.

DESIGN

Case-controls.

METHODS

Eighteen women diagnosed with FM and comorbid PTSD, 18 women diagnosed with FM and no PTSD, and 38 healthy women were exposed to an arithmetic task with harassment while blood pressure and heart rate were measured during task exposure and recovery.

RESULTS

Although heart rate response evidenced a general blunted reactivity for both groups of FM patients, only those with comorbid PTSD presented lower levels of reactivity in terms of their systolic blood pressure response. In addition, systolic blood pressure response was sensitive to the presence of depression in both groups of FM patients and controls. Finally, although both groups of FM patients showed significantly slower rates of recovery, their final recovery state was not worse after twelve minutes of recording.

CONCLUSIONS

Results of this study point to comorbid PTSD as a significant contributor to the blunted cardiovascular reactivity observed in FM patients, which may be dependent to a great extent on depressive symptomatology. As some degree of cardiovascular response to stress is functional in that it mobilizes energy and triggers the necessary compensatory mechanisms to manage stressors, this study supports the well-recognized clinical strategies of detection and treatment of PTSD and concomitant depression in the management of FM.

Sex-Specific Physiology and Cardiovascular Disease

Sex differences in cardiovascular diseases can be classified as those which are specific to one sex and those that differ in incidence, prevalence, etiology, symptomatology, response to treatment, morbidity, and mortality in one sex compared to the other. All sex differences in cardiovascular conditions have their basis in the combined expression of genetic and hormonal differences between women and men. This chapter addresses how understanding basic mechanisms of hormone responses, imaging diagnostics, and integration of genomics and proteomics has advanced diagnosis and improved outcomes for cardiovascular conditions, apart from those related to pregnancy that are more prevalent in women. These conditions include obstructive coronary artery disease, coronary microvascular dysfunction, spontaneous coronary artery dissection, diseases of the cardiac muscle including heart failure and takotsubo cardiomyopathy, and conditions related to neurovascular dysregulation including hot flashes and night sweats associated with menopause and effects of exogenous hormones on vascular function. Improvement in technologies allowing for noninvasive assessment of neuronally mediated vascular reactivity will further improve our understanding of the basic etiology of the neurovascular disorders. Consideration of sex, hormonal status, and pregnancy history in diagnosis and treatment protocols will improve prevention and outcomes of cardiovascular disease in women as they age.

Sex-Specific Association Between Coronary Artery Disease Severity and Myocardial Ischemia Induced by Mental Stress

OBJECTIVE

It is unclear whether mental stress-induced myocardial ischemia (MSIMI) is related to obstructive coronary artery disease (CAD). We examined this question and contrasted results with ischemia induced by conventional stress testing (CSIMI). Because women are more susceptible to ischemia without coronary obstruction than men, we examined sex differences.

METHODS

We studied 276 patients 61 years and younger with recent myocardial infarction. CAD severity was quantified using the log-transformed Gensini Score (lnGS) and the Sullivan Stenosis Score. Patients underwent myocardial perfusion imaging with mental stress (public speaking) and conventional (exercise or pharmacological) stress testing. MSIMI and CSIMI were defined as a new or worsening perfusion defect.

RESULTS

The prevalence of MSIMI was 15% in men and 20% in women. The median GS for patients with MSIMI was 65.0 in men and 28.5 in women. In logistic regression models adjusted for demographic and cardiovascular risk factors, CAD severity was associated with CSIMI in the full sample (odds ratio [OR] = 1.49, 95% [CI], 1.14-1.95, per 1-unit increase in lnGS), with no significant difference by sex. Although CAD severity was not associated with MSIMI in the entire sample, results differed by sex. CAD severity was associated with MSIMI among men (OR = 1.95, 95% CI, 1.13-3.36, per 1-unit increase in lnGS), but not among women (OR = 1.02, 95% CI, 0.74-1.42, p = .042 for interaction). Analysis using Sullivan Stenosis Score yielded similar results.

CONCLUSIONS

Findings suggest that CAD severity is related to MSIMI in men but not women. MSIMI in women may therefore be driven by alternative mechanisms such as coronary microvascular disease.

Blunted endocrine response to a combined physical-cognitive stressor in adults with early life adversity

The negative health effects of early life adversity (ELA) continue long into adulthood. Changes in the physiological response to psychosocial stressors have been proposed to mediate this effect. However, many previous studies have come to contradicting conclusions as to whether ELA induces a long-term increase or decrease in stress reactivity. Therefore, we tested the association of ELA exposure and adult stress reactivity in a sample of early life adoptees and controls. Two previously validated stressful elements (bilateral feet CPT and the Paced Auditory Serial Addition Task (PASAT)) were combined in an extended Cold Pressor Test (CPT). This test was performed on 22 participants who had experienced severe ELA (separation from biological parents, institutionalization, and adoption in early childhood), and in 22 age-matched control participants. A prior history of ELA was associated with blunted reactivity of the hypothalamic-pituitary-adrenal (HPA) axis (Cohen´s d = 0.680). Cardiovascular reactivity remained unchanged, and affective reactivity (self-report ratings) were increased in participants exposed to ELA compared to the control group (range Cohen´s d: 0.642-0.879). Our results suggest that the activity of the HPA axis reactivity was inhibited in ELA participants. Importantly, cardiovascular stress responsiveness was not affected by ELA. This separation of the HPA axis and cardiovascular stress responses may best be explained by ELA selectively enhancing central feedback-sensitivity to glucocorticoids, but preserving cardiovascular/ autonomic stress reactivity.

Altered autonomic reactivity in Korean military soldiers with adjustment disorder

Only few studies addressing the biological background of adjustment disorder (AD) exist. We examined the psychophysiological correlates indicative of autonomic regulation in AD. Heart rate variability (HRV), skin conductance, skin temperature, electromyography, and respiration were measured during serial stress tasks in 33 soldiers with AD and 60 healthy controls (HC). Patients with AD displayed lower relative power of high frequency (rHF) HRV and higher relative power of very low frequency (rVLF) HRV compared with HC at baseline. Inversely, the rHF of patients with AD remained higher and their rVLF remained lower compared with HC parameters after the single stress task, which suggests a reversed sympathovagal balance in AD. Mean heart rate and skin conductance increased during stress tasks in patients, although to a lesser extent than in HC. Skin temperature remained unchanged in all tasks in patients with AD. The tension of the frontalis muscle was higher in patients compared with HC from the second stress task onward. Thoracic breathing was more prevalent in patients with AD. Our study suggests altered autonomic reactivity in AD, which leads to a lack of sympathetic response to stress. We conclude that the distinctive biological mechanisms underlying AD are different from normal stress reactions.

Sex Differences in Hemodynamic and Microvascular Mechanisms of Myocardial Ischemia Induced by Mental Stress

OBJECTIVE

To investigate sex-specific vascular mechanisms for mental stress-induced myocardial ischemia (MSIMI).

APPROACH AND RESULTS

Baseline data from a prospective cohort study of 678 patients with coronary artery disease underwent myocardial perfusion imaging before and during a public speaking stressor. The rate-pressure product response was calculated as the difference between the maximum value during the speech minus the minimum value during rest. Peripheral vasoconstriction by peripheral arterial tonometry was calculated as the ratio of pulse wave amplitude during the speech over the resting baseline; ratios <1 indicate a vasoconstrictive response. MSIMI was defined as percent of left ventricle that was ischemic and as a dichotomous variable. Men (but not women) with MSIMI had a higher rate-pressure product response than those without MSIMI (6500 versus 4800 mm Hg bpm), whereas women (but not men) with MSIMI had a significantly lower peripheral arterial tonometry ratio than those without MSIMI (0.5 versus 0.8). In adjusted linear regression, each 1000-U increase in rate-pressure product response was associated with 0.32% (95% confidence interval, 0.22-0.42) increase in inducible ischemia among men, whereas each 0.10-U decrease in peripheral arterial tonometry ratio was associated with 0.23% (95% confidence interval, 0.11-0.35) increase in inducible myocardial ischemia among women. Results were independent of conventional stress-induced myocardial ischemia.

CONCLUSIONS

Women and men have distinct cardiovascular reactivity mechanisms for MSIMI. For women, stress-induced peripheral vasoconstriction with mental stress, and not increased hemodynamic workload, is associated with MSIMI, whereas for men, it is the opposite. Future studies should examine these pathways on long-term outcomes.

Clinical value of hyperemic left ventricular systolic function in vasodilator stress testing

Exercise results in increased left ventricular contractility in normal individuals. Similar changes can also be seen with vasodilator stress. This article discusses the physiologic basis of these changes as well as reviews the clinical data supporting the use of these parameters for diagnostic and prognostic evaluation. Methodologic limitations as well as other concomitant pathologic processes which may confound interpretation of stress-induced changes in LVEF are also reviewed.

Mental stress-induced left ventricular dysfunction and adverse outcome in ischemic heart disease patients

Aims Mental stress-induced myocardial ischemia (MSIMI) occurs in up to 70% of patients with clinically stable ischemic heart disease and is associated with increased risk of adverse prognosis. We aimed to examine the prognostic value of indices of MSIMI and exercise stress-induced myocardial ischemia (ESIMI) in a population of ischemic heart disease patients that was not confined by having a recent positive physical stress test. Methods and results The Responses of Mental Stress Induced Myocardial Ischemia to Escitalopram Treatment (REMIT) study enrolled 310 subjects who underwent mental and exercise stress testing and were followed annually for a median of four years. Study endpoints included time to first and total rate of major adverse cardiovascular events, defined as all-cause mortality and hospitalizations for cardiovascular causes. Cox and negative binomial regression adjusting for age, sex, resting left ventricular ejection fraction, and heart failure status were used to examine associations of indices of MSIMI and ESIMI with study endpoints. The continuous variable of mental stress-induced left ventricular ejection fraction change was significantly associated with both endpoints (all p values < 0.05). For every reduction of 5% in left ventricular ejection fraction induced by mental stress, patients had a 5% increase in the probability of a major adverse cardiovascular event at the median follow-up time and a 20% increase in the number of major adverse cardiovascular events endured over the follow-up period of six years. Indices of ESIMI did not predict endpoints ( ps > 0.05). Conclusion In patients with stable ischemic heart disease, mental, but not exercise, stress-induced left ventricular ejection fraction change significantly predicts risk of future adverse cardiovascular events.

Behavioral, emotional and neurobiological determinants of coronary heart disease risk in women

Women have more of the stress-related behavioral profile that has been linked to cardiovascular disease than men. For example, women double the rates of stress-related mental disorders such as depression and posttraumatic stress disorder (PTSD) than men, and have higher rates of exposure to adversity early in life. This profile may increase women's long-term risk of cardiometabolic conditions linked to stress, especially coronary heart disease (CHD). In addition to having a higher prevalence of psychosocial stressors, women may be more vulnerable to the adverse effects of these stressors on CHD, perhaps through altered neurobiological physiology. Emerging data suggest that young women are disproportionally susceptible to the adverse effects of stress on the risk of cardiovascular disease, both in terms of initiating the disease as well as worsening the prognosis in women who have already exhibited symptoms of the disease. Women's potential vulnerability to psychosocial stress could also help explain their higher propensity toward abnormal coronary vasomotion and microvascular disease compared with men.

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.

Treatment for diabetic foot ulcers complicated by major cardiac events

OBJECTIVE

Diabetic foot ulcer (DFU) is a major complication in patients with diabetes mellitus and the leading cause of non-traumatic amputation in adults. Patients with DFU are usually fragile due to chronic diabetic comorbidities; therefore, tedious debridement and intervention procedures may not be well tolerated in patients with DFU. This study aimed to identify a casual relationship between in-hospital complications and treatment for limb-threatening DFUs.

METHODS

From 2009 to 2011, 1130 consecutive patients who were admitted to the Diabetic Foot Care Center in Chang Gung Medical Center were surveyed. Rates of in-hospital mortality or events that lead to transfer to the intensive care unit (ICU) for various severe complications were retrospectively analyzed.

RESULTS

Forty-seven patients (4.2%) experienced in-hospital complications (28 patients died). Major adverse cardiac events (MACE) (n=21, 44.7%) were the most common complications, followed by nosocomial infection (n=18, 38.3%). Previous myocardial infarction was a risk factor for MACE. The presentation of MACE was fulminant (eg, acute pulmonary edema, cardiogenic shock,cardiac arrest), and occurred within 10 days of admission or within 10 days following a major procedure in most cases. ST-T segment abnormality at rest was the most common presentation of electrocardiography for MACE.

CONCLUSION

MACE should be prevented during treatment for limb-threatening DFU in high-risk patients. Acute stress might have caused MACE during the first 10 days after admission or a major procedure.

Confluence of depression and acute psychological stress among patients with stable coronary heart disease: effects on myocardial perfusion

Background

Depression is prevalent in coronary heart disease (CHD) patients and increases risk for acute coronary syndrome (ACS) recurrence and mortality despite optimal medical care. The pathways underlying this risk remain elusive. Psychological stress (PS) can provoke impairment in myocardial perfusion and trigger ACS. A confluence of acute PS with depression might reveal coronary vascular mechanisms of risk. We tested whether depression increased risk for impaired myocardial perfusion during acute PS among patients with stable CHD.

Methods and Results

Patients (N=146) completed the Beck Depression Inventory‐I (BDI‐I), a measure of depression linked to recurrent ACS and post‐ACS mortality, and underwent single‐photon emission computed tomography myocardial perfusion imaging at rest and during acute PS. The likelihood of new/worsening impairment in myocardial perfusion from baseline to PS as a function of depression severity was tested. On the BDI‐I, 41 patients scored in the normal range, 48 in the high normal range, and 57 in the depressed range previously linked to CHD prognosis. A BDI‐I score in the depressed range was associated with a significantly greater likelihood of new/worsening impairment in myocardial perfusion from baseline to PS (odds ratio =2.89, 95% CI: 1.26 to 6.63, P=0.012). This remained significant in models controlling ACS recurrence/mortality risk factors and medications. There was no effect for selective serotonin reuptake inhibitor medications.

Conclusions

Depressed patients with CHD are particularly susceptible to impairment in myocardial perfusion during PS. The confluence of PS with depression may contribute to a better understanding of the depression‐associated risk for ACS recurrence and mortality.

Myocardial ischemia and angiotensin-converting enzyme inhibition: comparison of ischemia during mental and physical stress

OBJECTIVE

Mental stress provokes myocardial ischemia in many patients with stable coronary artery disease (CAD). Mental stress-induced myocardial ischemia (MSIMI) portends a worse prognosis, independent of standard cardiac risk factors or outcome of traditional physical stress testing. Angiotensin II plays a significant role in the physiological response to stress, but its role in MSIMI remains unknown. Our aim was to evaluate whether the use of angiotensin-converting enzyme inhibitors (ACEIs) is associated with a differential effect on the incidence of MSIMI compared with ischemia during physical stress.

METHODS

Retrospective analysis of 218 patients with stable CAD, including 110 on ACEI, was performed. 99m-Tc-sestamibi myocardial perfusion imaging was used to define ischemia during mental stress, induced by a standardized public speaking task, and during physical stress, induced by either exercise or adenosine.

RESULTS

Overall, 40 patients (18%) developed MSIMI and 80 patients (37%) developed ischemia during physical stress. MSIMI occurred less frequently in patients receiving ACEIs (13%) compared with those not on ACEIs (24%; p = .030, adjusted odds ratio = 0.42, 95% confidence interval = 0.19-0.91). In contrast, the frequency of myocardial ischemia during physical stress testing was similar in both groups (39% versus 35% in those on and not on ACEIs, respectively); adjusted odds ratio = 0.91, 95% confidence interval = 0.48-1.73).

CONCLUSION

In this retrospective study, patients using ACEI therapy displayed less than half the risk of developing ischemia during mental stress but not physical stress. This possible beneficial effect of ACEIs on MSIMI may be contributing to their salutary effects in CAD.

Myocardial ischemia during mental stress: role of coronary artery disease burden and vasomotion

Background

Mental stress–induced myocardial ischemia (MSIMI) is associated with adverse prognosis in patients with coronary artery disease (CAD), yet the mechanisms underlying this phenomenon remain unclear. We hypothesized that compared with exercise/pharmacological stress–induced myocardial ischemia (PSIMI) that is secondary to the atherosclerotic burden of CAD, MSIMI is primarily due to vasomotor changes.

Methods and Results

Patients with angiographically documented CAD underwent ^99mTc‐sestamibi myocardial perfusion imaging at rest and following both mental and physical stress testing, performed on separate days. The severity and extent of CAD were quantified using the Gensini and Sullivan scores. Peripheral arterial tonometry (Itamar Inc) was used to assess the digital microvascular tone during mental stress as a ratio of pulse wave amplitude during speech compared with baseline. Measurements were made in a discovery sample (n=225) and verified in a replication sample (n=159). In the pooled (n=384) sample, CAD severity and extent scores were not significantly different between those with and without MSIMI, whereas they were greater in those with compared with those without PSIMI (P<0.04 for all). The peripheral arterial tonometry ratio was lower in those with compared with those without MSIMI (0.55±0.36 versus 0.76±0.52, P=0.009). In a multivariable analysis, the peripheral arterial tonometry ratio was the only independent predictor of MSIMI (P=0.009), whereas angiographic severity and extent of CAD independently predicted PSIMI.

Conclusions

The degree of digital microvascular constriction, and not the angiographic burden of CAD, is associated with MSIMI. Varying causes of MSIMI compared with PSIMI may require different therapeutic interventions that require further study.

Depression and cardiovascular disorders

During the past two decades, research in the field of depression and cardiovascular disorders has exploded. Multiple studies have demonstrated that depression is more prevalent in populations with cardiovascular disease, is a robust risk factor for the development of cardiovascular disease in healthy populations, and is predictive of adverse outcomes (such as myocardial infarction and death) among populations with preexisting cardiovascular disease. Mechanistic studies have shown that poor health behaviors, such as physical inactivity, medication nonadherence, and smoking, strongly contribute to this association. Small randomized trials have found that antidepressant therapies may improve cardiac outcomes. Based on this accumulating evidence, the American Heart Association has recommended routine screening for depression in all patients with coronary heart disease. This review examines the key epidemiological literature on depression and cardiovascular disorders and discusses our current understanding of the mechanisms responsible for this association. We also examine current recommendations for screening, diagnosis, and management of depression. We conclude by highlighting new research areas and discussing therapeutic management of depression in patients with cardiovascular disorders.

Prevalence and clinical characteristics of mental stress-induced myocardial ischemia in patients with coronary heart disease

OBJECTIVES

The goal of this study was to evaluate the prevalence and clinical characteristics of mental stress-induced myocardial ischemia.

BACKGROUND

Mental stress-induced myocardial ischemia is prevalent and a risk factor for poor prognosis in patients with coronary heart disease, but past studies mainly studied patients with exercise-induced myocardial ischemia.

METHODS

Eligible patients with clinically stable coronary heart disease, regardless of exercise stress testing status, underwent a battery of 3 mental stress tests followed by a treadmill test. Stress-induced ischemia, assessed by echocardiography and electrocardiography, was defined as: 1) development or worsening of regional wall motion abnormality; 2) left ventricular ejection fraction reduction ≥ 8%; and/or 3) horizontal or downsloping ST-segment depression ≥ 1 mm in 2 or more leads lasting for ≥ 3 consecutive beats during at least 1 mental test or during the exercise test.

RESULTS

Mental stress-induced ischemia occurred in 43.45%, whereas exercise-induced ischemia occurred in 33.79% (p = 0.002) of the study population (N = 310). Women (odds ratio [OR]: 1.88), patients who were not married (OR: 1.99), and patients who lived alone (OR: 2.24) were more likely to have mental stress-induced ischemia (all p < 0.05). Multivariate analysis showed that compared with married men or men living with someone, unmarried men (OR: 2.57) and married women (OR: 3.18), or living alone (male OR: 2.25 and female OR: 2.72, respectively) had higher risk for mental stress-induced ischemia (all p < 0.05).

CONCLUSIONS

Mental stress-induced ischemia is more common than exercise-induced ischemia in patients with clinically stable coronary heart disease. Women, unmarried men, and individuals living alone are at higher risk for mental stress-induced ischemia. (Responses of Myocardial Ischemia to Escitalopram Treatment [REMIT]; NCT00574847).

Role of Stress in Cardiac Arrhythmias

Stress is a major trigger of cardiac arrhythmias; it exerts profound effects on electrophysiology of the cardiomyocytes and the cardiac rhythm. Psychological and physiological stressors impact the cardiovascular system through the autonomic nervous system (ANS). While stressors vary, properties of the stress response at the level of cardiovascular system (collectively referred to as the autonomic cardiovascular responses) are similar and can be studied independently from the properties of specific stressors. Here, we will review the clinical and experimental evidence linking common stressors and atrial arrhythmias. Specifically, we will describe the impact of psychological and circadian stressors on ANS activity and arrhythmogenesis. We will also review studies examining relationships between autonomic cardiovascular responses and cardiac arrhythmias in ambulatory and laboratory settings.

Psychological Correlates of Mental Stress-induced Ischemia in the Laboratory: The Psychophysiological Investigation of Myocardial Ischemia (PIMI) Study

Participants consisted of 184 patients (160 males, 24 females) with positive angiograms or prior myocardial infarctions who displayed at least 1 mm of ST segment depression on a standardized treadmill test. Mean scores on the Reward Dependence subscale of the Tridimensional Personality Questionnaire were higher in patients displaying ischemia during mental stress. Patients who reported higher levels of irritability/anger in response to the Speech stressor were also more likely to display ischemia. However, this result was primarily a result of the females in the sample whose ratings of interest and irritability were associated with ischemia during the Speech task. Psychometric measures previously found in prospective studies to predict acute cardiac events were unrelated to mental stress-induced ischemia in the laboratory.

Panic attack triggering myocardial ischemia documented by myocardial perfusion imaging study. A case report

BACKGROUND

Chest pain, a key element in the investigation of coronary artery disease is often regarded as a benign prognosis when present in panic attacks. However, panic disorder has been suggested as an independent risk factor for long-term prognosis of cardiovascular diseases and a trigger of acute myocardial infarction.

OBJECTIVE

Faced with the extreme importance in differentiate from ischemic to non-ischemic chest pain, we report a case of panic attack induced by inhalation of 35% carbon dioxide triggering myocardial ischemia, documented by myocardial perfusion imaging study.

DISCUSSION

Panic attack is undoubtedly a strong component of mental stress. Patients with coronary artery disease may present myocardial ischemia in mental stress response by two ways: an increase in coronary vasomotor tone or a sympathetic hyperactivity leading to a rise in myocardial oxygen consumption. Coronary artery spasm was presumed to be present in cases of cardiac ischemia linked to panic disorder. Possibly the carbon dioxide challenge test could trigger myocardial ischemia by the same mechanisms.

CONCLUSION

The use of mental stress has been suggested as an alternative method for myocardial ischemia investigation. Based on translational medicine objectives the use of CO2 challenge followed by Sestamibi SPECT could be a useful method to allow improved application of research-based knowledge to the medical field, specifically at the interface of PD and cardiovascular disease.

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.

Anxiolytic-like effect of oxytocin in the simulated public speaking test

Oxytocin (OT) is known to be involved in anxiety, as well as cardiovascular and hormonal regulation. The objective of this study was to assess the acute effect of intranasally administered OT on subjective states, as well as cardiovascular and endocrine parameters, in healthy volunteers (n = 14) performing a simulated public speaking test. OT or placebo was administered intranasally 50 min before the test. Assessments were made across time during the experimental session: (1) baseline (-30 min); (2) pre-test (-15 min); (3) anticipation of the speech (50 min); (4) during the speech (1:03 h), post-test time 1 (1:26 h), and post-test time 2 (1:46 h). Subjective states were evaluated by self-assessment scales. Cortisol serum and plasma adrenocorticotropic hormone (ACTH) were measured. Additionally, heart rate, blood pressure, skin conductance, and the number of spontaneous fluctuations in skin conductance were measured. Compared with placebo, OT reduced the Visual Analogue Mood Scale (VAMS) anxiety index during the pre-test phase only, while increasing sedation at the pre-test, anticipation, and speech phases. OT also lowered the skin conductance level at the pre-test, anticipation, speech, and post-test 2 phases. Other parameters evaluated were not significantly affected by OT. The present results show that OT reduces anticipatory anxiety, but does not affect public speaking fear, suggesting that this hormone has anxiolytic properties.

Symptoms of anxiety and depression are correlates of angina pectoris by recent history and an ischemia-positive treadmill test in patients with documented coronary artery disease in the pimi study

Objective. We tested the association of specific psychological characteristics in patients having stable coronary disease with the reporting of anginal symptoms during daily activities, and positive exercise testing. Methods. One hundred and ninety-six patients with documented CAD enrolled in the Psychophysiological Investigations of Myocardial Ischemia (PIMI) Study completed an anginal history questionnaire and a battery of psychometric tests. They also underwent standardized exercise treadmill tests. Results. Patients with a recent history of angina were more likely to be female, and had higher Beck Depression (P = .002), State Anxiety (P = .001), Trait Anxiety (P = .03), Harm Avoidance (P = .04) and Muscle Tension (P = .004) scores than patients who had no recent history of angina. Along with several treadmill variables indicating more severe disease state and reduced exercise tolerance, patients who developed angina on a positive treadmill test also displayed higher scores on the Beck Depression Inventory (P = .003) and State Anxiety (P = .004) scales. Conclusions. Several psychological characteristics, and most notably anxiety and depression, are strong correlates of recent angina and angina in the presence of ischemia provoked by treadmill testing.

Globalization and modernization: an obesogenic combination

Animal research has well established that a link exists between variations in corticosteroids and the proneness to excess body fat accumulation. Accordingly, it is known that adrenalectomy is an efficient approach to counteract weight gain in most animal models of obesity. In humans, the association between variations in corticosteroids, its stress-related environmental effects and the predisposition to obesity is more difficult to demonstrate. In this paper, we propose that this relationship is accentuated by globalization and modernization which favour a labour context imposing additional stress and changes in life habits promoting a positive energy balance. Our main hypothesis is that the increase in knowledge-based work, and the decrease of quality and duration of sleep both induce an increase in cortisolaemia and glycaemia instability, which results in an increase in food intake, a reduction in energy expenditure and body fat gain. The authors of this paper believe that, from a socioeconomic perspective, globalization leads every nation of the world in conflict with itself and may consequently represent a real problem. On one hand, there are preoccupations related to productivity and money making. On the other hand, people have to adopt a daily lifestyle leading to hyperphagia and decreased energy expenditure in order to maintain their economic competitiveness.

Comparing EndoPAT and BIOPAC measurement of vascular responses to mental stress

There are currently no comparison measurements of stress-induced changes in vascular function during acute mental stress tests to measurements made by BIOPAC MP150 systems technology, a standard polygraph device used to detect deception during polygraph examinations in military or law enforcement applications. Vascular responses to reactive hyperaemia and acute mental stress in 25 healthy subjects were measured by both peripheral arterial tonometry (EndoPAT) and a blood pressure cuff attached to a pressure transducer (BIOPAC) and compared. Reactive hyperaemia was performed at baseline and following three acute mental stress tests. There was no difference in vascular reactivity at baseline and following acute mental stress, as measured by EndoPAT or BIOPAC systems (p > 0·05). Mental stress ratios measured by EndoPAT were significantly different than those measured by BIOPAC (p < 0·01). These data suggest that EndoPAT measurements of vascular responses to acute mental stress may be more specific and sensitive than measurements using the BIOPAC system.

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.

Emotional stress triggers symptoms in hypertrophic cardiomyopathy: a survey of the Hypertrophic Cardiomyopathy Association

BACKGROUND

Symptoms are among the most important factors impacting quality of life (QOL) in hypertrophic cardiomyopathy (HCM) patients, and reflect a poor prognosis. Whether emotional stress can trigger symptoms of chest pain, dyspnea, palpitations, and lightheadedness has not been described.

METHODS

Members of the Hypertrophic Cardiomyopathy Association (HCMA) received an electronic link via e-mail to an ongoing online survey, also accessed via links on the HCMA message-board and homepage. Between May 2007 and November 2008, there were 1,297 respondents. The survey queried demographic and self-reported clinical information, and types and triggers of symptoms. Respondents reported physical and emotional QOL on a 1-10 Likert scale.

RESULTS

Symptoms reported included chest pain (49%), dyspnea (70%), palpitations (61%), and syncope/lightheadedness (59%). The most common symptom trigger was exertion, 64% describing symptoms while climbing stairs or hills. Forty-nine percent described experiencing symptoms during emotional stress. Those reporting chest pain were more likely to report emotion triggering (60%) than those reporting palpitations, syncope/lightheadedness, or dyspnea (50-54% each). Both physical and emotional QOL were significantly decreased in those describing emotion-triggered symptoms. Women were more likely than men to report symptoms overall, as well as emotion-triggered symptoms (50% vs 35%, P < 0.001) and exertion-triggered symptoms (79% vs 58%, P < 0.001). After controlling for presence of symptoms, both emotion- and exertion-triggered symptoms remained significantly more common in women.

CONCLUSIONS

Triggering of symptoms by emotion is common in individuals with HCM. Further studies will determine pathways linking emotional stressors with chest pain, dyspnea, palpitations, and lightheadedness in these patients.

Heart-brain interactions in mental stress-induced myocardial ischemia

Myocardial ischemia that results from emotional provocation occurs in as many as 30% to 50% of patients with coronary artery disease during the discourse of their lives. This emotionally provoked or mental stress ischemia is associated with poor prognosis, with emerging treatment strategies. This article outlines the conceptual constructs that support the pathophysiologic underpinnings, and biobehavioral aspects associated with this mental stress ischemia. We review a biobehavioral model in which cognitive stress is transduced in the brain. The response of the brain to psychosocial stress is a highly sophisticated and integrated process by which sensory inputs are evaluated and appraised for their importance in relation to previous experience and current goals. The biologic consequences of such stress transduced in the central nervous system has its effect on cardiovascular flow and function through changes in autonomic balance, which result in various biologic processes that culminate in the perturbation of flow and function of the heart.

Are older adults less or more physiologically reactive? A meta-analysis of age-related differences in cardiovascular reactivity to laboratory tasks

In this meta-analytic review of 31 laboratory studies, we examined if relatively older adults showed lower or higher cardiovascular reactivity compared with relatively younger adults. Results revealed that age was associated with lower heart rate reactivity but higher systolic blood pressure (SBP) reactivity during emotionally evocative tasks. Consistent with the predictions of dynamic integration theory, the result for SBP was moderated by the degree of task activation. These data are discussed in light of existing self-regulatory models and important future research directions.

Usefulness of peripheral arterial tonometry in the detection of mental stress-induced myocardial ischemia

BACKGROUND

Mental stress-induced myocardial ischemia (MSIMI) identifies a subset of coronary arterial disease (CAD) patients at increased risk for adverse cardiovascular events. Peripheral arterial vasoconstriction has been consistently reported as an underlying mechanism for ischemia development in this setting and as such affords a unique opportunity for the noninvasive detection of this phenomenon.

HYPOTHESIS

We studied the usefulness of a peripheral arterial tonometry (PAT) technique in the detection of MSIMI. We sought to identify response patterns that would predict the development of MSIMI.

METHODS

Participants were 211 patients with documented CAD. Mental stress testing was performed using a public speaking task. Rest-stress myocardial perfusion imaging was the gold standard for ischemia detection. PAT responses were assessed during the 2 phases of the stressful task (stress anticipation and the task performance) and were calculated as a ratio of stress to the resting pulse wave amplitude.

RESULTS

Vascular response during the stress anticipation period (speech preparation) was more pronounced than during the actual speaking task (the mean preparation index was 0.64 +/- 0.53; the mean speech index was 0.72 +/- 0.60; P < 0.001). PAT response during speech preparation had modest accuracy for predicting MSIMI (area under the curve [AUC] was 0.63; 95% confidence interval [CI]: 0.53-0.74, P = 0.015). A PAT index < or = 0.52 was identified as the best cut off value for detecting MSIMI with a sensitivity of 76% and a specificity of 56%.

CONCLUSION

We identified a pattern of peripheral arterial response to mental stress that has a relatively modest accuracy in predicting MSIMI. Further research is needed to validate the findings of this study.

Effects of a cognitive stress challenge on myocardial perfusion and plasma cortisol in coronary heart disease patients with depression

Although it is well established that coronary heart disease (CHD) patients with depression exhibit increased mortality compared with equally ill cardiac patients without depression, the mechanisms mediating this effect remain obscure. Depression is characterized by vulnerability to stress and heightened stress responsiveness, and stress can theoretically act through several biological pathways to contribute to excess mortality from CHD. Mechanisms connecting stress, depression and cardiovascular mortality have not been previously explored in detail. The purpose of this study was to assess the effects of stress and depression on myocardial perfusion and plasma cortisol concentrations in CHD patients. Patients with CHD with and without depression (n = 28) underwent single photon emission computed tomography imaging of myocardial perfusion at rest and during a stressful cognitive challenge. Severity of ischaemia was measured by summing perfusion defect scores across myocardial segments and subtracting out rest from stress scores. Plasma cortisol concentrations were measured at baseline and in response to the stressful challenge. There were no differences in stress-induced myocardial ischaemia or plasma cortisol response to stress between CHD patients with and without depression. Depressed CHD patients with a history of psychological trauma (n = 5) had an increase in stress-induced ischaemia scores [7; standard deviation (SD) = 5] compared with CHD patients with depression without a history of psychological trauma (2 SD = 2) and CHD patients without depression or psychological trauma (1; SD = 2) (F = 8.51; degree of freedom = 2,23; p = 0.007). Eighty per cent of CHD/depression trauma-exposed subjects had stress-induced ischaemia as opposed to 38 per cent of CHD/depression subjects without trauma exposure and 23 per cent of subjects with CHD without depression or trauma. Self-reported nervousness during the cognitive stressor was correlated with stress-induced ischaemia. These preliminary findings suggest that depression with a history of prior exposure to traumatic stress is associated with increased risk for stress-induced cardiovascular ischaemia.

Usefulness of laboratory mental stress test in patients with stable coronary artery disease

BACKGROUND AND HYPOTHESIS

Many episodes of ischemia in daily life are silent occurring during sedentary activities and may be related to mental stress. In 35 patients with stable angina and positive exercise test awaiting bypass surgery, we investigated whether laboratory mental stress tests would trigger ischemia of a comparable severity to that occurring in daily life and attempted to elucidate some of the underlying mechanisms.

METHODS

All patients underwent exercise testing, personality assessment, 2-day Holter monitoring, and laboratory mental stress tests while on their usual medications.

RESULTS

Only four patients (12%) had positive mental stress test (ST depression > or = 0.1 mV). All episodes were silent and usually associated with fast heart rate (> 90 beats/min). In contrast, ambulatory ischemia was common (average duration of 51 min per 24 h), and at least one episode was recorded in 27 patients (77%) including the 4 with positive test. Patients with positive mental stress test had a higher heart rate during testing (124 +/- 24 vs. 86 +/- 16 beats/min, p < 0.01), and a shorter exercise time and time to 1 mm ST depression on cycle ergometry than those with negative mental stress test. None of the four patients were on beta blockers. There was no difference in personality inventory between the two groups. Comparisons between patients with and without positive mental stress test revealed no difference in the duration and frequency of ambulatory ischemia, or in the occurrence of silent ischemia. However, the heart rate at onset of ambulatory ischemia tended to be higher in the patients with positive mental stress test (96 +/- 9 vs. 62 +/- 43, p = 0.07). Further subgroup analysis in patients without beta blockers (4 mental stress test positive and 18 negative) showed similar results.

CONCLUSIONS

Laboratory mental stress test is a weak inducer of ischemia detected by electrocardiographic monitoring in patients with frequent ambulatory ischemia. Wall motion evaluation during mental stress test may improve sensitivity. While larger scale studies may determine its clinical role, the present study illustrated that patients with heightened heart rate response to mental stress were identified in whom beta blockers could be the drug of choice.

Sex differences in vascular and endothelial responses to acute mental stress

OBJECTIVE

Our objective was to assess the differences in systemic vascular and endothelial function in response to acute mental stress between men and women. The endothelium plays a pivotal role in vascular homeostasis and the development of atherosclerotic heart disease. The mechanism and presentation of cardiovascular events show a sex-based difference, although the sex difference in the vascular and endothelial response to mental stress is not known.

METHODS

Male (n = 34) and female (n = 53) subjects participated in a series of three different mental stress tasks during which vascular response was measured non-invasively using peripheral arterial tonometry. Endothelial function was assessed using reactive hyperemia peripheral arterial tonometry. Double product (systolic blood pressure x heart rate) was calculated.

RESULTS

Males had a greater double product response (27.2 + 3.6% increase in double product vs. 19.2 + 1.7%; P = 0.01), and a greater vascular reactivity to mental stress. Females demonstrated a reduced response to reactive hyperemia (-0.47 vs. 13.74%; P = 0.01). Furthermore, a subgroup of females who showed the least vaso-reactivity to mental stress showed the greatest decline in endothelial function (-10.5 + 4% vs. 17.4 + 6.3%; P < 0.001).

INTERPRETATION

This study demonstrates sex-based differences in the vascular and endothelial responses to mental stress. The mental stress-induced reduction in endothelial function and increased double product seen in the females might manifest clinically as contributing to the pathophysiology of mental stress-mediated cardiovascular events in female patients and provide further information regarding the potential mechanism for sex differences in cardiac events.

A study on pathogenesis of sudden death syndrome in broiler chickens

Sudden death syndrome (SDS) in fast growing broiler chickens has been recognized as a patho-physiological entity for four decades, but its pathogenesis still remains unknown. More recent investigations provided evidence that link SDS to cardiac arrhythmia, but the mechanism triggering arrhythmogenesis and factors responsible for fatal outcome are poorly understood. In order to understand the chain of events leading to SDS in broilers, the present study focused on putative mechanisms that trigger arrhythmia and mechanisms that predispose the myocardium to fatal arrhythmia. Susceptibility of broilers to cardiac arrhythmia under stress conditions was evaluated using a simulated stress test with epinephrine. Detailed histopathological evaluation of the broiler heart was undertaken to identify structural features that may predispose the myocardium to fatal arrhythmia. The simulated stress challenge revealed that many broilers are highly susceptible to stress induced cardiac arrhythmia. In some broilers the stress challenge induced severe ventricular arrhythmia, and the life threatening nature of this arrhythmia was evidenced by the fact that several birds showing the most severe arrhythmic responses, died suddenly within several days after the stress challenge. Examination of hearts of broilers that died of SDS revealed microscopic lesions in the cardiomyocytes, and widespread changes in the sub-endocardial and mural His-Purkinje system (HPS). Immune staining for Caspase-3 confirmed that numerous Purkinje cells in the left ventricular myocardium from broiler chickens that died of SDS were undergoing apoptosis. The observed lesions suggest that the electrical stability of the myocardium was compromised. Taken together, our findings indicate that stress is a most likely trigger of cardiac arrhythmia in broilers, whereas the pathological changes seen in the myocardium and in the HPS in fast growing broilers provide a very conducive milieu for sustained ventricular arrhythmia. In cases where the electrical stability of the myocardium is compromised, even an episodic arrhythmic event may readily degenerate to catastrophic ventricular fibrillation and sudden death. We conclude that the combination of stress and changes in the cardiomyocytes and HPS are the key requisite features in the pathogenesis of SDS.