Induction of silent myocardial ischemia with mental stress testing: relation to the triggers of ischemia during daily life activities and to ischemic functional severity

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.

Mental Stress-Induced Myocardial Ischemia

PURPOSE OF REVIEW

To summarize recent evidence on mental stress-induced myocardial ischemia (MSIMI), its mechanisms, and clinical significance.

RECENT FINDINGS

MSIMI can occur in patients with normal cardiac stress testing, is only weakly related to severity of coronary artery disease (CAD), and it is often silent. Among patients with CAD, MSIMI is associated with a twofold increased risk of major adverse cardiovascular events compared to those who do not have MSIMI. Certain groups such as young women with myocardial infarction and those with psychological comorbidities are more susceptible to MSIMI. Abnormal microvascular vasoreactivity and inflammation are implicated mechanisms in MSIMI. Increased brain activity in regions that modulate autonomic reactivity to emotional stress and fear is associated with MSIMI. MSIMI has important prognostic implications in patients with CAD. Stress can no longer be ignored as a risk factor in cardiology care. Clinical trials testing effective strategies to target MSIMI are needed.

Consistency of Positron Emission Tomography and Myocardial Contrast Echocardiography in Diagnosing Mental Stress-Induced Myocardial Ischemia: Study Protocol of a Prospective Study-Background, Design and Method

Mental stress-induced myocardial ischemia (MSIMI) has attracted increasing attention in the last 30 y. Positron emission tomography/computed tomography (PET/CT) is among the most accurate methods for evaluating myocardial perfusion. Even so, echocardiography seems to be a more harmless option when the radiation exposure and high expense of PET/CT are considered. To date, no previous studies have compared the consistency between echocardiography and PET/CT in the diagnosis of MSIMI. The primary aim of this research was to compare the consistency of myocardial contrast echocardiography and PET/CT in diagnosing MSIMI in women with angina symptom/ischemia but no obstructive coronary artery disease (INOCA). Fifty adult female patients with INOCA were recruited for a 12-min-long mental stress test. Each patient underwent both echocardiography and PET/CT at baseline and during mental stress testing; the interval between the two examinations was 1-3 d and the sequence was assigned naturally. MSIMI is defined by a summed difference score (SDS) ≥3 on PET-CT during mental stress testing. It is also defined by new abnormal wall motion, ejection fraction reduction ≥5%, and/or development of ischemic ST change on the electrocardiogram during mental stress testing. This study examined the consistency of PET/CT and myocardial contrast echocardiography in diagnosing MSIMI.

Peripheral Vasoconstriction During Mental Stress and Adverse Cardiovascular Outcomes in Patients With Coronary Artery Disease

RATIONALE

Excessive vasoconstriction in response to mental stress may be a potential mechanism by which acute psychological stress leads to adverse cardiac events.

OBJECTIVES

We investigated whether excessive digital vasoconstriction during acute mental stress predicts adverse cardiovascular outcomes among patients with coronary artery disease.

METHODS AND RESULTS

Five hundred forty-nine patients with stable coronary artery disease (age 63±9, 76% male, 29% black) underwent mental stress testing with a standardized public speaking stressor and followed prospectively for cardiovascular end points. Digital pulse wave amplitude was continuously measured using peripheral artery tonometry (PAT, Itamar Inc). Stress/rest PAT ratio (sPAT) of pulse wave amplitude during mental stress/baseline was calculated and dichotomized by the median value into low and high sPAT ratio groups. Upon 3-year follow-up, Fine and Gray's subdistribution hazard ratios were used to examine the association between sPAT ratio and the composite end point of cardiovascular death, myocardial infarction, revascularization, and hospitalization for heart failure. The median sPAT ratio was 0.68 (interquartile range, 0.48-0.88), indicating 32% vasoconstriction with mental stress. Men were more likely to have low sPAT ratio than women (odds ratio, 1.79; P=0.007) while those on β-blockers were less likely to have low sPAT ratio (odds ratio, 0.52; P=0.003). After adjusting for demographic and cardiovascular risk factors, medications, and rate-pressure product change during mental stress, those with low sPAT ratio were at significantly higher risk of adverse outcomes (subdistribution hazard ratio, 1.77 [95% CI, 1.12-2.80]).

CONCLUSIONS

Greater peripheral vasoconstriction with mental stress, denoted by a low sPAT ratio, is associated with a higher risk of adverse cardiovascular outcomes in patients with coronary artery disease.

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.

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.

Electrocardiographic features for the measurement of drivers' mental workload

This study examines the effect of mental workload on the electrocardiogram (ECG) of participants driving the Lane Change Task (LCT). Different levels of mental workload were induced by a secondary task (n-back task) with three levels of difficulty. Subjective data showed a significant increase of the experienced workload over all three levels. An exploratory approach was chosen to extract a large number of rhythmical and morphological features from the ECG signal thereby identifying those which differentiated best between the levels of mental workload. No single rhythmical or morphological feature was able to differentiate between all three levels. A group of parameters were extracted which were at least able to discriminate between two levels. For future research, a combination of features is recommended to achieve best diagnosticity for different levels of mental workload.

Analytical parameters and vital signs in patients subjected to dental extraction

Background

Dental consultation may provoke stress to the patient, especially when a dental surgery is going to be performed, stressful situations can cause a reaction in the sympathetic nervous system that could lead to cardiovascular alterations. Blood pressure and cardiac frequency are used often as an indirect measurement and this parameters combined can serve as good indicators of stress. Objective: Analyze the changes in vital signs and analytical parameters induced by a dental extraction.

Material and Methods

24 healthy patients who required a simple dental extraction underwent to a blood test and motorization of their pre- and post-extraction vital signs before, at 2 and 48 hours after the procedure. Data analysis was performed by means of repeated measures one way ANOVA followed by multiple comparisons Bonferroni’s Post-hoc test.

Results

The evaluated patients were 13 women and 11 men with an average age of 35.1. Thirteen patients (54.17% of the sample) were smokers and five were regular drinkers (20.8%). No significant differences were observed in the vital signs with the exception of diastolic blood pressure and cardiac rate that were slightly lower after extraction. Only two analytical parameters showed statistical significant changes. Total bilirubin was significantly higher at 48 hours after extraction and leukocyte count was significantly lower at this time. In any case, the magnitude of the changes observed was very low. The analytical parameters and the vital signs did not show any relevant change.

Conclusions

Eventual alterations found after simple tooth extraction should not be attributed to the procedure.

Key words:Blood pressure, heart rate, monitoring physiologic, oxygen saturation, tooth extraction.

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.

Acute psychological and physical stress transiently enhances brachial artery flow-mediated dilation stimulated by exercise-induced increases in shear stress

Exercise elevates conduit artery shear stress and stimulates flow-mediated dilation (FMD). However, little is known regarding the impact of acute psychological and physical stress on this response. The purpose of this study was to examine the impact of the Trier Social Stress Test (TSST (speech and arithmetic tasks)) and a cold pressor test (CPT) with and without social evaluation (SE) on exercise-induced brachial artery FMD (EX-FMD). A total of 59 healthy male subjects were randomly assigned to 1 of 3 conditions: TSST, CPT, or CPT with SE. During 6 min of handgrip exercise, brachial artery EX-FMD was assessed before and 15 and 35 min poststress with echo and Doppler ultrasound. Shear stress was estimated as shear rate, calculated as brachial artery mean blood velocity/brachial artery diameter. Results are means ± SD. All conditions elicited significant physiological stress responses. Salivary cortisol increased from 4.6 ± 2.4 nmol/L to 10.0 ± 5.0 nmol/L (p < 0.001; condition effect: p = 0.292). Mean arterial pressure increased from 98.6 ± 12.1 mm Hg to 131.9 ± 18.7 mm Hg (p < 0.001; condition effect: p = 0.664). Exercise shear rate did not differ between conditions (p = 0.592), although it was modestly lower poststress (prestress: 72.3 ± 4.5 s−1; 15 min poststress: 70.8 ± 5.4 s−1; 35 min poststress: 70.6 ± 6.1 s−1; trial effect: p = 0.011). EX-FMD increased from prestress to 15 min poststress in all conditions (prestress: 6.2% ± 2.8%; 15 min poststress: 7.9% ± 3.2%; 35 min poststress: 6.6% ± 2.9%; trial effect: p < 0.001; condition effect: p = 0.611). In conclusion, all conditions elicited similar stress responses that transiently enhanced EX-FMD. This response may help to support muscle perfusion during stress.

Brain natriuretic hormone predicts stress-induced alterations in diastolic function

BACKGROUND

Mental stress (MS) reduces diastolic function (DF) and may lead to congestive heart failure with preserved systolic function. Whether brain natriuretic hormone (brain natriuretic peptide [BNP]) mediates the relationship of MS with DF is unknown.

METHODS

One hundred sixty individuals aged 30 to 50 years underwent 2-hour protocol of 40-minute rest, videogame stressor and recovery. Hemodynamics, pro-BNP samples and DF indices were obtained throughout the protocol. Separate regression analyses were conducted using rest and stress E/A, E' and E/E' as dependent variables. Predictor variables were entered into the stepwise regression models in a hierarchical fashion. At the first level, age, sex, race, height, body mass index, pro-BNP and left ventricular mass (LVM) were permitted to enter the models. The second level consisted of systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR). The final level contained cross-product terms of race by SBP, DBP and HR.

RESULTS

E/A ratio was lower during stress compared to rest and recovery (P < 0.01). Resting E/A ratio was predicted by a regression model of age (-0.31), pro-BNP (0.16), HR (-0.40) and DBP (-0.23) with an R² = 0.33. Stress E/A ratio was predicted by age (-0.24), pro-BNP (0.08), HR (-0.38) and SBP (-0.21) with total R² = 0.22. Resting E' model consisted of age (-0.22), pro-BNP (0.26), DBP (-0.27) and LVM (-0.15) with an R² = 0.29. Stress E' was predicted by age (-0.18), pro-BNP (0.35) and LVM (-0.18) with an R² = 0.18. Resting E/E' was predicted by race (0.17, B > W) and DBP (0.24) with an R² = 0.10. Stress E/E' consisted of pro-BNP (-0.36), height (-0.26) and HR (-0.21) with an R² = 0.15.

CONCLUSIONS

pro-BNP predicts both resting and stress DF, suggesting that lower BNP during MS may be a marker of diastolic dysfunction in apparently healthy individuals.

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.

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.

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.

Anger, emotion, and arrhythmias: from brain to heart

Strong emotion and mental stress are now recognized as playing a significant role in severe and fatal ventricular arrhythmias. The mechanisms, although incompletely understood, include central processing at the cortical and brain stem level, the autonomic nerves and the electrophysiology of the myocardium. Each of these is usually studied separately by investigators from different disciplines. However, many are regulatory processes which incorporate interactive feedforward and feedback mechanisms. In this review we consider the whole as an integrated interactive brain-heart system.

Enhancing standard cardiac rehabilitation with stress management training: background, methods, and design for the enhanced study

PURPOSE

Enhancing Standard Cardiac Rehabilitation with Stress Management Training in Patients with Heart Disease (ENHANCED) is a randomized clinical trial funded by the National Heart Lung and Blood Institute to evaluate the effects of stress management training (SMT) on changes in biomarkers of risk and quality of life for patients enrolled in traditional exercise-based cardiac rehabilitation (CR).

METHODS

One hundred fifty cardiac patients recruited from Duke University and the University of North Carolina will be evaluated and randomized to CR enhanced by SMT (including sessions devoted to relaxation training, cognitive restructuring, communication skills, and problem solving) or to standard exercise-based CR. Before and after 12 weeks of treatment, patients will undergo a battery of psychometric questionnaires and evaluation of cardiovascular biomarkers, including measures of flow-mediated dilation, heart rate variability, baroreflex sensitivity, platelet function and inflammation, and ischemia during laboratory mental stress testing. The primary outcomes include a composite measure of stress (distress, depression, anxiety, and hostility and 24-hour urinary catecholamines and cortisol) and a composite measure of cardiac biomarkers of risk (vascular endothelial function, cardiac vagal control, inflammation, platelet function, and mental stress-induced myocardial ischemia). Secondary outcomes include measures of quality of life as well as clinical events, including death, hospitalizations, myocardial infarction, and revascularization procedures.

RESULTS

This article reviews prior studies in the area and describes the design of the ENHANCED study. Several key methodological issues are discussed including the assessment of biomarkers of risk and barriers to the integration of SMT into traditional CR.

CONCLUSIONS

The ENHANCED study will provide important information by determining to what extent SMT combined with exercise-based CR may improve prognosis and quality of life in vulnerable cardiac patients.

Psychic trauma as cause of death

AIM

of study Psychic trauma is described as the action of 'an emotionally overwhelming factor' capable of causing neurovegetative alterations leading to transitory or persisting bodily changes. The medico-legal concept of psychic trauma and its definition as a cause in penal cases is debated. The authors present three cases of death after psychic trauma, and discuss the definition of cause within the penal ambit of identified 'emotionally overwhelming factors'.

MATERIALS AND METHODS

The methodological approach to ascertainment and criterion-based assessment in each case involved the following phases: (1) examination of circumstantial evidence, clinical records and documentation; (2) autopsy; (3) ascertainment of cause of death; and (4) ascertainment of psychic trauma, and its coexisting relationship with the cause of death.

RESULTS

The results and assessment of each of the three cases are discussed from the viewpoint of the causal connotation of psychic trauma. In the cases presented, psychic trauma caused death, as deduced from assessment of the type of externally caused emotional insult, the subjects' personal characteristics and the circumstances of the event causing death.

CONCLUSIONS

In cases of death due to psychic trauma, careful methodological ascertainment is essential, with the double aim of defining 'emotionally overwhelming factors' as a significant cause of death from the penal point of view, and of identifying the responsibility of third parties involved in the death event and associated dynamics of homicide.

Neurohormonal and inflammatory hyper-responsiveness to acute mental stress in depression

Depression is associated with dysregulated hypothalamic-pituitary-adrenal (HPA) axis function, overactivity of the sympathoadrenal system, and increased levels of inflammation markers. It is not known whether these biological processes are disproportionately elevated in response to acute negative emotional arousal by mental stress (MS). The present study investigates responses of neurohormones and inflammatory markers to MS in 14 clinically depressed (age: 42+/-10 years; 50% female) and 14 non-depressed control (age: 39+/-6 years; 50% female) participants. Heightened acute MS reactivity was documented in depressed participants (adrenocorticotropic hormone, rho=0.001; norepinephrine, rho=0.042; epinephrine, rho=0.039), and a delayed increase in cortisol was observed (rho=0.002). Inflammation markers increased more strongly in depressed versus non-depressed participants (IL-6, rho=0.027; tumor necrosis factor-alpha, rho=0.050; and recovery C-reactive protein, rho=0.003). It is concluded that depressed individuals display hyper-reactivity of neuroimmunological markers in response to acute negative emotions. This hyper-reactivity may serve a pathologic role in the elevated morbidity and mortality risk associated with depression.

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.

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.

Comparison of peripheral arterial response to mental stress in men versus women with coronary artery disease

There are profound gender-related differences in the incidence, presentation, and outcomes of coronary artery disease (CAD). These differences are not entirely explained by traditional cardiovascular risk factors. Nontraditional risk factors, such as psychological traits, have increasingly been recognized as important contributors to the genesis and outcomes of CAD. Mental stress induces significant peripheral arterial vasoconstriction, with consequent increases in heart rate and blood pressure. These changes are thought to underlie the development of myocardial ischemia and other mental stress-induced adverse cardiac events in patients with CAD. This study examined for gender-related differences in peripheral arterial response to mental stress in a cohort of patients with CAD using a novel peripheral arterial tonometric (PAT) technique. There were 211 patients (77 women; 37%) with a documented history of CAD and a mean age of 64 +/- 9 years. Patients were enrolled from August 18, 2004, to February 21, 2007. Mental stress was induced using a public speaking task. Hemodynamic and PAT measurements were recorded during rest and mental stress. The PAT response was calculated as a ratio of pulse wave amplitude during stress to at rest. PAT responses were compared between men and women. The PAT ratio (during stress to at rest) was significantly higher in women compared with men. Mean PAT ratio was 0.80 +/- 0.72 in women compared with 0.59 +/- 0.48 in men (p = 0.032). This finding remained significant after controlling for possible confounding factors (p = 0.037). In conclusion, peripheral vasoconstrictive response to mental stress was more pronounced in men compared with women. This finding may suggest that men have higher susceptibility to mental stress-related adverse effects. Additional studies are needed to determine the significance of this finding.

Variability of myocardial ischemic responses to mental versus exercise or adenosine stress in patients with coronary artery disease

BACKGROUND

Mental stress precipitates myocardial ischemia in a significant percentage of coronary artery disease (CAD) patients. Exercise or adenosine stresses produce different physiologic responses and cause myocardial ischemia via different mechanisms. Little is known about the comparative severity and location of myocardial ischemia provoked by these different stressors. In this study we sought to compare the within-individual ischemic responses to mental versus exercise or adenosine stress in a cohort of CAD patients.

METHODS AND RESULTS

All patients underwent mental stress and either exercise or adenosine testing within a 1-week period. Mental stress was induced via a public speaking task. Rest-stress myocardial perfusion imaging was used with all testing protocols. Participants were 187 patients (65 women [35%]) with a documented history of CAD and a mean age of 64 +/- 9 years. Mental stress-induced myocardial ischemia (MSIMI) was less prevalent and frequently of less magnitude than exercise- or adenosine-induced ischemia. Ischemia induced by exercise or adenosine testing did not accurately predict the development or the location of MSIMI. The overall concordance between these stressors for provoking ischemia was weak (percent agreement, 71%; kappa [+/- SE], 0.26 +/- 0.07). In a minority of patients (11%) mental stress provoked ischemia in the absence of exercise- or adenosine-induced ischemia. Moreover, in patients who had myocardial ischemia during both stressors, there were significant within-individual differences in the coronary artery distribution of the ischemic regions. MSIMI was more likely to occur in a single-vessel distribution (86%) compared with exercise- or adenosine-induced ischemia (54%). The stressors had moderate agreement if the ischemic region was in the right coronary artery territory (percent agreement, 76%; kappa, 0.52 +/- 0.19) or the left anterior descending coronary artery (percent agreement, 76%; kappa, 0.51 +/- 0.19) and significantly lower agreement in the left circumflex territory (percent agreement, 62%; kappa, 0.22 +/- 0.18).

CONCLUSIONS

Our findings indicate that mental and exercise or adenosine stresses provoke different myocardial ischemic responses. These observations suggest that exercise or adenosine testing may not adequately assess the likelihood of occurrence or severity of MSIMI and that different mechanisms are operative in each condition.

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.

Do men and women differ on measures of mental stress-induced ischemia?

OBJECTIVE

To consider the effects of gender on ischemia in a larger sample, with broadly defined coronary artery disease (CAD). Mental stress has been shown to cause transient myocardial ischemia in a significant percentage of people with CAD. However, little is known about the effects of mental stress on ischemic processes in women. Most studies to date either had few women or required a positive exercise stress test.

METHODS

Participants (61 women, 93 men; average age = 63 years) had documented CAD (positive stress test, abnormal catheterization even with minimal disease, or previous myocardial infarction). They underwent mental stress testing and radionuclide perfusion imaging (stress/ rest). Cardiac function data were collected and stress was compared with baseline. The data were then submitted to a series of analyses of variance.

RESULTS

A total of 50 (32%) participants exhibited reversible ischemia post psychological stress. This reflects a relative rate of 33% (n = 31 of 93) for men and 31% (n = 19 of 61) for women. No difference between men and women were observed on any measure of hemodynamic functioning (blood pressure, heart rate, or cardiac perfusion).

CONCLUSIONS

Results of this study showed no significant differences between men and women on measures of hemodynamic functioning or cardiac perfusion.

Mental stress hemodynamic responses and myocardial ischemia: does left ventricular dysfunction alter these relationships?

OBJECTIVE

To assess if mental stress hemodynamic responses are impaired and related to mental stress (MS) ischemia in patients with left ventricular (LV) dysfunction.

BACKGROUND

Impaired LV function is an important coronary artery disease (CAD) risk factor and hemodynamic characteristics play an important role in clinical outcomes. Patients with severe LV dysfunction (SLVD) are frequently excluded from prior studies and the effects of LV dysfunction on MS hemodynamic responses are not known.

METHODS

Fifty-eight patients with CAD, consisting of 22 patients with normal LV function (ejection fraction (EF) > or =50%), 16 patients with mild-to-moderate LV dysfunction (30% < EF < 50%), and 20 patients with severe LV dysfunction (EF < or =30) underwent bicycle exercise (EX) and MS testing with 12-lead electrocardiogram and monitoring of vital signs on consecutive days in random order. Blood pressure and heart rate (HR) measurements were obtained. Ischemia was measured using single photon emission computed tomography.

RESULTS

Both MS and EX produced significant increases in all hemodynamic measurements. HR levels were higher both at rest and during MS in SLVD patients. LV groups increased similarly from rest to stress (both MS and EX) for all measurements except HR during MS, which increased more in patients with SLVD than patients with normal LV function. Hemodynamic responses to MS were not related to myocardial ischemia or heart failure symptoms.

CONCLUSIONS

HR response during MS is increased in patients with SLVD, whereas blood pressure responses are similar to those in patients with preserved LV function. Hemodynamic reactivity is unrelated to MS-induced ischemia.

Mast cell deficient W/Wv mice have lower serum IL-6 and less cardiac tissue necrosis than their normal littermates following myocardial ischemia-reperfusion

Myocardial ischemia-reperfusion (IR) injury complicates all forms of coronary artery revascularization. Circulating interleukin-6 (IL-6) has been implicated in cell death following a variety of stimuli. Macrophages, platelets, neutrophils and the endothelium have been shown to release IL-6 after IR injury. Cardiac mast cells have been implicated in IR; however, their involvement has never been quantified. In this randomized, prospective study, we compared cardiac tissue susceptibility and serum IL-6 changes between mast cell deficient (W/Wv) mice and their normal littermates (+/+). Twenty-eight male W/Wv mice (n=14) and their +/+ littermates (n=14) were anaesthetized with 2.5% isoflurane. The left coronary artery (LCA) was ligated for 30 minutes or a sham procedure was performed. After 6 hours of reperfusion, the animals were sacrificed. The muscle viability was assessed on fresh whole-mount slices by nitroblue tetrazolium (NBT) histochemical assay and serum IL-6 concentrations measured by ELISA. Cardiac muscle viability was significantly higher in W/Wv mice than the +/+ mice. Serum IL-6 levels were higher in the +/+ sham mice (465 +/- 32 pg/ml, n=6) than the W/Wv mice (185 +/- 31 pg/ml, n=6), p < 0.001. The IL-6 levels increased significantly after reperfusion only in the +/+ mice (698 +/- 41 pg/ml, n=8, p = 0.001), while it remained similar in the W/Wv mice (202 +/- 48 pg/ml, n=8, p = 0.783). These results show that the absence of mast cells reduces the myocardial damage associated with IR injury. Furthermore, there is an attenuation in the inflammatory response, as measured by serum IL-6 levels, following this local insult. This finding entertains the prospect of developing prophylactic therapy--targeting selective inhibition of cardiac mast cell activation, in clinical situations involving medical or surgical myocardial revascularization.

The effect of compound nutrients on stress-induced changes in serum IL-2, IL-6 and TNF-alpha levels in rats

The effect of compound nutrients on serum concentrations of the cytokines, such as interleukin (IL)-2, tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 in immobilization and cold water-immersion stressed rat were investigated. Oral (gavage) administration of compound nutrients was found to attenuate the acute and chronic immobilization and cold water-immersion stress-induced increase in serum IL-6 level and decrease in IL-2 level. Compound nutrients exerted different effects on TNF-alpha level in two different models studied, with reduced serum TNF-alpha level in acute stress, while no significant effect in chronic stress. These results suggested that compound nutrients might be proposed as a possible candidate in the research or therapeutic modulation of stress-related disorders.

Triggering effect of physical and mental stress on spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators

BACKGROUND

Physical and mental stress as well as sexual activity are potential triggering factors of acute coronary events and sudden cardiac death.

HYPOTHESIS

These factors may also trigger recurrence of spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators (ICDs).

METHODS

We performed a case-crossover study in 43 consecutive patients with 95 symptomatic, ICD-documented tachyarrhythmic events and calculated the relative risk of tachyarrhythmia recurrence during physical and mental stress. Physical and mental activity was graded on a 4-step intensity scale, and stress was defined as physical exertion or mental stress with an intensity grade > or = II during or up to 1 h before arrhythmia recurrence. Relative risk was determined taking into account the habitual weekly stress frequency of each patient.

RESULTS

Physical stress was present in 26% (n = 25), mental stress in 24% (n = 23), and sexual activity in 2% (n = 2) of analyzed events. The weekly habitual stress frequency was 8 +/- 8 (median 7) for physical stress, 6 +/- 6 (median 4) for mental stress, and 0.5 +/- 0.5 (median 0.25) for sexual activity. Thus, relative risk of arrhythmia recurrence during the presence of stress was 7.5 for physical activity (95% confidence interval [CI] 5.2-11.1), 9.5 (CI 6.3-14.5) for mental activity, and 7.5 (CI 2.3-24.8) for sexual activity.

CONCLUSIONS

Physical and mental stress as well as sexual activity are factors that significantly increase relative risk of spontaneous recurrence of sustained ventricular tachyarrhythmias in patients with ICDs. Consideration of this stress-related relative risk increase may contribute to avoidance of harmful shock delivery in ICD recipients.

Mental stress and coronary artery disease: a multidisciplinary guide

Research suggests that acute and chronic stress are risk factors for the development and progression of coronary artery disease. Much of this work is multidisciplinary, using unfamiliar concepts deriving from disciplines other than cardiology and medicine. This article addresses and clarifies, for the cardiologist, some of the key concepts and issues in this area and provides an overview of evidence linking acute and chronic stress to cardiac pathology. Areas addressed include definitions and measurement of mental stress, methodological issues in stress research, and distinctions between stress and variables such as personality, emotion, and depression. Mental stress is a multifactorial process involving the environment, individual experiences and coping, and a set of neuroendocrine, autonomic, cardiovascular, and other systemic physiologic responses. There are difficulties identifying a single consensus physiologic stress measure because of individual differences in perceptions and physiologic response patterns. Nonetheless, important associations exist between mental stress and clinically relevant cardiovascular end points. As multidisciplinary research in this area continues, one major goal is the better integration of psychosocial knowledge and measures with cardiology research and practice.

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

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

Haemodynamic effects of mental stress during cardiac arrest simulation testing on advanced life support courses

We investigated the haemodynamic response to the mental stress induced by being evaluated as a team leader in simulated advanced life support (ALS) scenarios.

METHODS

Healthcare providers participating as candidates to ALS courses were monitored while acting as team leaders in a cardiac arrest testing scenario (CASTest). Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured before, during and after the CASTest. The correlation between the haemodynamic responses and sex, age, body mass index (BMI) and marks on course multiple choice questions (MCQs) were studied using multiple linear regression.

RESULTS

Eighty-eight subjects (46 women, 42 men, mean age 34.9+/-6.8 years) were enrolled. Mean HR, SBP and DBP increased significantly during the CASTest and reached a peak after a phase of the scenario which included an unsuccessful defibrillation. Ten minutes after the CASTest, HR, SBP and DBP were still significantly higher than their respective baseline values. A significant positive correlation was found between the DBP and SBP response during the scenario and the BMI, and between the DBP response and the candidates' age. The haemodynamic stress response was neither correlated with the candidates' marks in the course MCQ nor with their instructor potential (IP).

CONCLUSION

During the testing scenario the ALS candidates showed a significant haemodynamic response to mental stress, which depended mainly on their age and BMI rather than on their knowledge and skills.

Myocardial perfusion study of panic attacks in patients with coronary artery disease

Panic disorder (PD) and panic-like anxiety have been associated with an increased risk of cardiovascular death. No study has specifically examined the association between panic attacks and ischemia in patients who have coronary artery disease (CAD). We hypothesized that panic attacks would induce myocardial perfusion defects in patients who have CAD and PD. Sixty-five patients who had CAD and positive results with nuclear exercise stress testing (35 with PD and 30 without PD served as controls) underwent a well-established panic challenge test (1 vital capacity inhalation of a gas mixture containing 35% carbon dioxide and 65% oxygen) and were injected with technetium-99m sestamibi at inhalation. Single-photon emission computed tomography was used to assess per-panic challenge perfusion defects, and heart rate, blood pressure, and 12-lead electrocardiogram were continuously measured during the procedure. Patients were not withdrawn from their cardiac medications. Patients who had PD were significantly younger than the controls; otherwise groups did not differ with respect to gender, cardiac medications, nuclear exercise test results, and baseline heart rate and blood pressure. Seventy-four percent of patients (26 of 35) who had PD had a panic attack at inhalation versus 6.7% of controls (2 of 30, p <0.001). As hypothesized, patients who had PD and demonstrated a panic attack were more likely to develop a reversible myocardial perfusion defect than were controls who did not have an attack (80.9% vs 46.4% p = 0.009). Thus, despite being on their cardiac medications, panic attacks preferentially induced significant perfusion defects in patients who had CAD and PD. In conclusion, panic attacks in patients who have CAD appear to be bad for the heart.

Depression and Anxiety in Heart Failure

BACKGROUND

Although common among patients with heart failure, depression and anxiety have been relatively neglected by researchers and practitioners. Both depression and anxiety have been implicated in contributing independently to the poor outcomes seen in patients with heart failure. Emphasis in the literature is on physical symptom recognition and management, in contrast to the patient's perspective of the effects of heart failure on his or her daily life.

METHODS AND RESULTS

This review summarizes and integrates research findings on anxiety and depression and translates these findings to clinical practice. Depression and anxiety are prevalent among patients with heart failure and require assessment and intervention. Short-term nonpharmacologic approaches, in conjunction with drug therapy, hold promise for successful management of patients who are depressed or anxious.

CONCLUSION

Carefully designed clinical trials that are tailored to individual needs, yet are embedded within a systemic framework, are needed to inform clinicians regarding optimal practices for the treatment of patients with heart failure who suffer from depression or anxiety.

The effect of mental stress on the non-dipolar components of the T wave: modulation by hypnosis

OBJECTIVE

Mental or emotional stress-induced ventricular arrhythmias and sudden cardiac death are thought to be mediated by the autonomic nervous system and ischemia. In the absence of ischemia, increased inhomogeneity of repolarization is thought to be important. We tested the hypotheses that in the absence of ischemia, mental stress may modulate repolarization by changing autonomic balance; and mental relaxation induced by hypnosis may offset the potentially adverse effects of stress on the cardiac electrophysiology.

METHODS

Twelve healthy volunteers (6 male, age 18-35, mean 25 years) experienced a series of different emotions intended to induce a wide range of autonomic response (42 test epochs) on two separate occasions, with and without hypnosis, with continuous electrocardiogram recording. Low- (LF) and HF (high-frequency) heart rate variability was measured and ventricular repolarization was assessed using the relative T-wave residua (proportion of nondipolar components of the T wave) calculated for the T-onset - T peak (TWR-peak T), T peak -T end (TWR-end T), and the whole T wave (TWR).

RESULTS

Emotionally induced changes in LF and LF/HF ratio correlated with changes in TWR, e.g., (R = 0.51, p < .001; R = 0.59, p < .0001; and R = 0.59, p < .0003, for LF/HF versus TWR, TWR-Peak T, and TWR-end T, respectively. Mental relaxation induced by hypnosis increased LF power (1,205 ms2) versus 624 ms2, p < .003 for hypnotized versus nonhypnotized state), HF power (1,619 ms2 versus 572 ms2), p < .0004), and reduced LF/HF ratio (1.0 versus 1.5, p = .052) and was associated with a marked reduction in the changes in repolarization in response to emotion, e.g., 10.7 x 10(-6) versus 5.0 x10(-6), p < .03 for TWR.

CONCLUSIONS

a) Mental stress in the absence of ischemia altered repolarization inhomogeneity via change in the autonomic balance. b) Mental relaxation induced by hypnosis greatly reduced the effect of mental stress on repolarization. c) These findings may have implications for arrhythmogenesis.

Emotions in everyday life: an ambulatory monitoring study with female students

Additional heart rate as an indicator of emotional arousal was monitored throughout the day with a special ambulatory device. Fifty female students received acoustic feedback every 10-20 min. The feedback was based either on events (additional heart rate present) or was random without additional heart rate. Following the feedback the subjects were asked to disclose their emotions. The following emotions were listed on the display of the monitoring device: no emotion, happiness, anger, anxiety/fear, sadness, surprise, and disgust. The frequency and quality of the emotions were not different between event-related and random feedbacks, indicating that the subjects were not able to discriminate between events with and without additional heart rate correctly. Accordingly, the physiological profiles of the differing emotions compared to conditions with "no emotion" were equivocal. The psychological ratings of excitement and enjoyment, however, came up to expectations. The results show that cognitive schemata and personality dimensions are more important in emotion perception than physiological activation.

Comparison of mental stress-induced myocardial ischemia in coronary artery disease patients with versus without left ventricular dysfunction

To examine the susceptibility to myocardial ischemia with mental stress in patients who have coronary artery disease and normal left ventricular (LV) function versus those who have impaired LV function, we examined 58 patients who had coronary artery disease, including 22 who had normal LV function (ejection fraction >/=50%), 16 who had mild to moderate LV dysfunction (ejection fraction 30% to 50%), and 20 who had severe LV dysfunction (ejection fraction </=30%) and underwent bicycle and mental stress testing with myocardial perfusion scintigraphy on consecutive days in random order. Ischemia was assessed based on summed difference scores in regional rest versus stress myocardial perfusion and defined as a summed difference score >3. At comparable double products across the 3 groups, ischemia was induced with mental stress more frequently in patients who had severe LV dysfunction (50%) than in those who had normal LV function (9%; p <0.01). The frequency of exercise-induced ischemia was different only between those who had mild/moderate LV dysfunction and those who had normal LV function (56% vs 18%, respectively, p <0.05). The pattern of mental stress versus exercise ischemia differed between groups (p <0.02): there was a higher prevalence of mental stress ischemia versus exercise ischemia in patients who had severe LV dysfunction (p = 0.06), a marginally higher prevalence of exercise versus mental stress ischemia in those who had moderate LV dysfunction (p = 0.07), and no difference in mental stress versus exercise ischemia in those who had normal LV function. Thus, at comparable double products during mental stress and similar extent of coronary artery disease, ischemia with mental stress was induced more frequently in patients who had severe LV dysfunction than in those who had normal LV function. These data suggest that mental stress ischemia may be of particular clinical importance in patients who have coronary artery disease and LV dysfunction.

Heart rate variability

BACKGROUND

The authors conducted a study to evaluate the sensitivity of heart rate variability, or HRV, in quantifying the cardiocirculatory reaction to dental stress compared with other clinical parameters more frequently used in clinical practice.

METHODS

Twenty-five healthy subjects (15 men and 10 women aged 19 through 73 years) who underwent dental extractions were enrolled in the study. The authors measured systolic blood pressure, or SBP; diastolic blood pressure, or DBP; heart rate, or HR; and HRV at baseline, immediately after local anesthetic was administered, during the dental extraction and five minutes after the dental extraction. Time domain measures of HRV were based on interbeat intervals and were obtained by using standard deviations of the R-R intervals, which were calculated during a five-minute period in a continuous electrocardiographic record.

RESULTS

Analysis of variance for repeated measures showed no time-related difference between the four study periods with regard to SBP and DBP. However, HR values were significantly different in three of the four periods, and HRV values were significantly different in all four testing periods. Furthermore, HRV values exhibited greater variability in the maximum changes recorded during dental extractions compared with HR values (0 to 80 milliseconds versus 0 to 31 beats/minute, respectively).

CONCLUSIONS

HRV is a highly sensitive parameter for quantifying the sympathetic drive to the heart during a cardiovascular reaction to a dental operation.

CLINICAL IMPLICATIONS

Clinicians may find that HRV evaluation is useful in monitoring patients with heart disease to detect early signs of cardiac impairment related to local, high sympathetic activity and to prevent cardiovascular emergencies.

Acute and chronic psychological stress in coronary disease

PURPOSE OF REVIEW

Coronary artery disease (CAD) is the leading cause of death in the United States and other developed countries. Along with a number of other factors thought to contribute to the high prevalence of CAD in developed societies (longer life expectancy, obesity, sedentary lifestyles), various psychological and social factors appear to promote the development or worsening of heart disease. It is well recognized that stress can be harmful to the cardiovascular system. The combination of the preexisting vulnerability and the major stressor are believed to result in cardiac arrhythmias and/or plaque rupture leading to death.

RECENT FINDINGS

Recently, the epidemiologic evidence of a link between stress and CAD is very convincing, yet the biopsychosocial pathway that would explain how stress can lead to disease is less clear. Different types of psychological stress have been found to be associated with increased cardiovascular events. Evidence regarding the efficacy of psychosocial interventions is also presented.

SUMMARY

It is suggested that, taken as a whole, evidence for a psychological and social impact on CAD morbidity and mortality is convincing.

What's “Unstable” in Unstable Angina?

The role of emotional distress (e.g., anger, depression, and anxiety) in anginal chest discomfort (ACD) may have been underestimated. The authors review the empirical studies in this area, which are inconsistent with the standard theory on the ischemia-angina relationship; summarize the substantial evidence indicating a strong and consistent cross-sectional/prospective epidemiological association of emotional distress and ischemia/ACD; review the distress-targeted, interventional evidence confirming a causal relationship (i.e., reduced chest discomfort and health system utilization), thus confirming clinical utility of such interventions; and explore the possible mechanisms that might account for the relationship between emotional distress and chest discomfort. Substantial clinical benefit may be achieved by aggressively detecting and treating emotional distress in ACD patients.

Correlations between preprocedure mood and clinical outcome in patients undergoing coronary angioplasty

We studied the relationship between mood and mood shift immediately before percutaneous coronary intervention (PCI) and 3 end points: total ischemic burden during PCI, adverse cardiac end points (ACE) after PCI, and death by 6-month follow up. Patients (n = 119) with unstable angina or myocardial infarction completed a visual analog scale (VAS) twice before PCI; before and after a session of stress relaxation, imagery, or touch; or approximately 30 minutes apart for patients assigned to prayer or to standard care. VAS included happiness, satisfaction, calm, hope, worry, shortness of breath, fear, and sadness. We observed a significant correlation between higher hope score before PCI and lower ischemic burden. Patients who experienced ACE had significantly lower hope and happiness scores than those who did not. Patients who survived to 6 months had significantly greater increases in worry and in hope. Our data suggest correlations between simple mood assessments before PCI and clinical outcomes during and after the procedure. More study is needed to understand whether attempts to alter patient mood can affect clinical outcomes.

Effects of mental stress on flow-mediated brachial arterial dilation and influence of behavioral factors and hypercholesterolemia in subjects without cardiovascular disease

Mental and emotional arousal are known to trigger coronary events. The relation between hypercholesterolemia, behavioral factors, and mental stress-induced alterations in endothelial function are not well defined. Flow-mediated brachial arterial vasodilation has been established as a measure of arterial endothelial function. High-resolution ultrasound was used to measure mental stress-mediated, flow-mediated, and the combination of mental stress- and flow-mediated brachial artery dilation in 38 subjects, 20 of whom had total cholesterol levels > or =200 mg/dl. Mental stress was provoked by anger recall and mental arithmetic and trait hostility were assessed using the Cook-Medley scale. Under mental stress, participants with hypercholesterolemia showed less vasodilation than participants without hypercholesterolemia, even after adjustment for age and the magnitude of blood pressure response to mental stress. Mental stress attenuated flow-mediated brachial arterial vasodilation. There was an inverse relation between hostile affect and percent change in brachial artery diameter after mental stress combined with hyperemia (r = -0.57, p <0.001). Thus, hypercholesterolemia is associated with impaired vasodilation in response to mental stress. Mental stress inhibits flow-mediated vasodilation in normal subjects and those with hypercholesterolemia. The magnitude of this inhibition is associated with hostility.

Simultaneous assessment of myocardial perfusion and function during mental stress in patients with chronic coronary artery disease

BACKGROUND

Mental stress (MS) is an important provocateur of myocardial ischemia in many patients with chronic coronary artery disease. The majority of laboratory assessments of ischemia in response to MS have included measurements of either myocardial perfusion or function alone. We performed this study to determine the relationship between alterations in perfusion and ventricular function during MS. Methods and results Twenty-eight patients with reversible perfusion defects on exercise or pharmacologic stress myocardial perfusion imaging (MPI) underwent simultaneous technetium 99m sestamibi single photon emission computed tomography (SPECT) MPI and transthoracic echocardiography at rest and during MS according to a mental arithmetic protocol. In all cases the MS study was performed within 4 weeks of the initial exercise or pharmacologic MPI that demonstrated ischemia. SPECT studies were analyzed visually with the use of a 13-segment model and quantitatively by semiautomated circumferential profile analysis. Echocardiograms were graded on a segmental model for regional wall motion on a 4-point scale. Of 28 patients, 18 (64%) had perfusion defects and/or left ventricular dysfunction develop during MS: 9 (32%) had myocardial perfusion defects develop, 6 (21%) had regional or global left ventricular dysfunction develop, and 3 (11%) had both perfusion defects and left ventricular dysfunction develop. The overall concordance between perfusion and function criteria for ischemia during MS was only 46%. Among 9 patients with MS-induced left ventricular dysfunction, 5 had new regional wall motion abnormalities and 4 had a global decrement in function. In patients with MS-induced ischemia by SPECT, the number of reversible perfusion defects was similar during both MS and exercise/pharmacologic stress (2.8 +/- 2.0 vs 3.5 +/- 1.8, P =.41). Hemodynamic changes during MS were similar whether patients were divided on the basis of perfusion defects or left ventricular dysfunction during MS.

CONCLUSIONS

These data indicate the feasibility of simultaneous assessment of perfusion and function responses during MS. Flow and function responses to MS are frequently not concordant. These data suggest that MS-induced changes in perfusion may represent a different phenomenon than MS-induced changes in left ventricular function (either globally or regionally).

Psychosocial influences on the development and course of coronary heart disease: current status and implications for research and practice

Psychosocial characteristics predict the development and course of coronary heart disease (CHD). In this review, the authors discussed human and animal research on psychophysiological mechanisms influencing coronary artery disease and its progression to CHD. They then reviewed literature on personality and characteristics of the social environment as risk factors for CHD. Hostility confers increased risk, and a group of risk factors involving depression and anxiety may be especially important following myocardial infarction. Social isolation, interpersonal conflict, and job stress confer increased risk. Psychosocial interventions may have beneficial effects on CHD morbidity and mortality, although inconsistent results and a variety of methodological limitations preclude firm conclusions. Finally, they discussed implications for clinical care and the agenda for future research.

Effects of psychological and social factors on organic disease: a critical assessment of research on coronary heart disease

An extensive research literature in the behavioral sciences and medicine suggests that psychological and social factors may play a direct role in organic coronary artery disease (CAD) pathology. However, many in the medical and scientific community regard this evidence with skepticism. This chapter critically examines research on the impact of psychological and psychosocial factors on the development and outcome of coronary heart disease, with particular emphasis on studies employing verifiable outcomes of CAD morbidity or mortality. Five key variables identified as possible psychosocial risk factors for CAD are addressed: acute and chronic stress, hostility, depression, social support, and socioeconomic status. Evidence regarding the efficacy of psychosocial interventions is also presented. It is suggested that, taken as a whole, evidence for a psychological and social impact on CAD morbidity and mortality is convincing. However, continued progress in this area requires multidisciplinary research integrating expertise in cardiology and the behavioral sciences, and more effective efforts to communicate research findings to a biomedical audience.