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

Psychological factors and cardiac repolarization instability during anger in implantable cardioverter defibrillator patients

Background

Evidence indicates that emotions such as anger are associated with increased incidence of sudden cardiac death, but the biological mechanisms remain unclear. We tested the hypothesis that, in patients with sudden death vulnerability, anger would be associated with arrhythmic vulnerability, indexed by cardiac repolarization instability.

Methods

Patients with coronary artery disease (CAD) and an implantable cardioverter defibrillator (ICD; n = 41) and healthy controls (n = 26) gave an anger‐inducing speech (anger recall), rated their current (state) anger, and completed measures of trait (chronic) levels of Anger and Hostility. Repolarization instability was measured using QT Variability Index (QTVI) at resting baseline and during anger recall using continuous ECG.

Results

ICD patients had significantly higher QTVI at baseline and during anger recall compared with controls, indicating greater arrhythmic vulnerability overall. QTVI increased from baseline to anger recall to a similar extent in both groups. In ICD patients but not controls, during anger recall, self‐rated anger was related to QTVI (r = .44, p = .007). Trait (chronic) Anger Expression (r = .26, p = .04), Anger Control (r = −.26, p = .04), and Hostility (r = .25, p = .05) were each associated with the change in QTVI from baseline to anger recall (ΔQTVI). Moderation analyses evaluated whether psychological trait associations with ΔQTVI were specific to the ICD group. Results indicated that Hostility scores predicted ΔQTVI from baseline to anger recall in ICD patients (β = 0.07, p = .01), but not in controls.

Conclusions

Anger increases repolarization lability, but in patients with CAD and arrhythmic vulnerability, chronic and acute anger interact to trigger cardiac repolarization lability associated with susceptibility to malignant arrhythmias.

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.

A meta-analysis on the prevalence, associated factors and diagnostic methods of mental stress induced myocardial ischemia

Background

The high prevalence of mental stress induced myocardial ischemia (MSIMI) causes double risk of adverse cardiac events in patients with MSIMI. However, multiple types of mental stress, diagnostic techniques, and diagnostic measurements may increase the complexity and heterogeneity in the assessment of MSIMI. Therefore, we performed this meta-analysis to assess the prevalence, associated factors, and diagnostic methods of MSIMI.

Methods

We systematically searched PubMed, EMBACE, Web of Science, CNKI, Wanfang through 1 Feb 2020 in English and Chinese. Review Manager (RevMan) Version 5.3 and Stata 12.0 were used for data analyses.

Results

Twenty articles were enrolled. The pooled estimates for the prevalence of MSIMI in CAD patients was 32%. Potential associated factors of MSIMI involved history of post myocardial infarction (MI), or coronary artery bypass graft (CABG) (RR: 1.29, 95% CI 1.00–1.66, P = 0.05; RR: 1.59, 95% CI 1.00–2.52, P = 0.05). Evidence supported that diagnostic methods could influence the prevalence of MSIMI. Significant differences of MSIMI prevalence were found in different types of mental stress (Public Speaking: 22%; Mental arithmetic: 26%; Anger recall: 34%; Two types: 37%; Three or more than three types: 43%, P = 0.02), diagnostic techniques (SPECT: 26%; RNV: 38%; ECG: 16%; Echocardiography: 41%; Two types: 43%, P < 0.0001), and diagnostic measurements (LVEF decrease: 19%; WMA: 51%; ST depression: 16%; MPD: 26%; Two or more than two measurements: 45%, P < 0.00001). Moreover, univariate meta-regression demonstrated that MSIMI was linked with mental stress (exp(b): 1.0508, SE: 0.0201, P: 0.018).

Conclusions

This meta-analysis implicated that patients with diabetes, post MI or CABG might be more vulnerable to MSIMI. However, the prevalence of MSIMI could be influenced by diagnostic methods, especially the adopted types of mental stress, diagnostic techniques and measurements. Therefore, it is necessary to formulate a standard diagnostic method for MSIMI, which should be adequate, assessable, and affordable worldwide.

Registration PROSPERO. Online Protocol: CRD42020162822.

Brain Correlates of Mental Stress-Induced Myocardial Ischemia

OBJECTIVE

Coronary artery disease (CAD) is a major cause of morbidity and mortality, and despite important advances in our understanding of this disorder, the underlying mechanisms remain under investigation. Recently, increased attention has been placed on the role of behavioral factors such as emotional stress on CAD risk. Brain areas involved in memory and the stress response, including medial prefrontal cortex, insula, and parietal cortex, also have outputs to the peripheral cardiovascular system. The purpose of this study was to assess the effects of mental stress on brain and cardiac function in patients with CAD.

METHODS

CAD patients (N = 170) underwent cardiac imaging with [Tc-99m] sestamibi single-photon emission tomography at rest and during a public speaking mental stress task. On another day, they underwent imaging of the brain with [O-15] water positron emission tomography (PET) during mental stress (arithmetic and public speaking) and control conditions.

RESULTS

Patients with mental stress-induced myocardial ischemia showed increased activation with stress in anterior cingulate, inferior frontal gyrus, and parietal cortex (p < .005). This was seen with both arithmetic stress and public speaking stress. Arithmetic stress was additionally associated with left insula activation, and public speaking with right pre/postcentral gyrus and middle temporal gyrus activation (p < .005).

CONCLUSIONS

These findings suggest that mental stress-induced myocardial ischemia is associated with activation in brain areas involved in the stress response and autonomic regulation of the cardiovascular system. Altered brain reactivity to stress could possibly represent a mechanism through which stress leads to increased risk of CAD-related morbidity and mortality.

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.

The Mental Stress Ischemia Prognosis Study: Objectives, Study Design, and Prevalence of Inducible Ischemia

OBJECTIVE

Mental stress-induced myocardial ischemia (MSIMI) is a common phenomenon in patients with coronary artery disease (CAD), but contemporary studies of its prognostic significance and its underlying pathophysiology are limited.

METHODS

We prospectively enrolled patients with confirmed CAD in the Mental Stress Ischemia Prognosis Study (MIPS) between 2011 and 2014. All patients underwent mental stress testing using a standardized public speaking task, and ischemia was detected by Tc-sestamibi myocardial perfusion imaging. Patients also underwent conventional stress testing for myocardial ischemia (CSIMI) using exercise or pharmacological stress testing. Furthermore, digital microvascular flow, endothelial function, arterial stiffness, and blood sample collections were performed before, during, and after mental stress. Two-year adverse clinical outcomes are being assessed.

RESULTS

Six-hundred ninety-five patients completed baseline enrollment in the MIPS. Their mean (standard deviation) age was 62.9 (9.1) years, 72% were men, 30% were African American, and 32% had a history myocardial infarction. The prevalence of MSIMI and CSIMI is 16.1% and 34.7%, respectively. A total of 151 patients (22.9%) had only CSIMI, 28 (4.2%) had only MSIMI, and 78 (11.8%) had both MSIMI and CSIMI. Patients with ischemia had a lower ejection fraction and higher prevalence of previous coronary artery bypass grafting compared with those without inducible ischemia (p < .050). The prevalence of obstructive CAD was not statistically different between patients with and without MSIMI (p = .426); in contrast, it was higher in patients with CSIMI (p < .001).

CONCLUSIONS

The MIPS data will provide useful information to assess the prognostic significance and underlying mechanisms of MSIMI.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Emotional triggering of cardiac dysfunction: the present and future

Mental stress and emotional arousal can act as triggers of acute myocardial infarction and other adverse cardiovascular outcomes. Experimental research examining mechanisms of the adverse interplay between mind and heart has led to the discovery of mental stress-induced cardiac dysfunction or myocardial ischemia (MSIMI). Evidence about the prevalence, clinical significance, and mechanistic bases of MSIMI outlines a wide range of central and peripheral bio-pathologic processes that are associated with emotions and behaviors. MSIMI is recognized as an integrated and intermediate biomarker underpinning the negative mind-heart interplay. Particularly, MSIMI research paves the way toward investigations aiming more specifically at recognizing the susceptibilities of individuals who are prone to respond adversely to the psycho-social-environmental stress. This article reviews recent literature on MSIMI research following the comprehensive review of Strike and Steptoe Eur Heart J 24:690-703, 2003. Further, this article outlines the main steps in the identification of the specific bio-pathologic manifestations of the cardiovascular system to emotional stress. Finally, a speculative description is provided of future directions in better searching for areas that may be critical targets in resolving adverse mind-heart interplays.

Psychological stress and short-term hospitalisations or death in patients with heart failure

OBJECTIVE

Standard predictors do not fully explain variations in the frequency and timing of heart failure (HF) adverse events (AEs). Psychological stress can trigger acute cardiovascular (CV) events, but it is not known whether stress can precipitate AEs in patients with HF. We investigated prospective associations of psychological stress with AEs in patients with HF.

METHODS

144 patients with HF (77% male; 57.5±11.5, range 23-87 years, left ventricular ejection fraction ≤40%) were longitudinally evaluated for psychological stress (Perceived Stress Scale) and AEs (CV hospitalisations/death) at 2-week intervals for 3 months and at 9-month follow-up.

RESULTS

42 patients (29.2%) had at least one CV hospitalisation and nine (6.3%) died. Patients reporting high average perceived stress across study measurements had a higher likelihood of AEs during the study period compared with those with lower stress (odds ratio=1.10, 95% confidence interval=1.04 to 1.17). In contrast to average levels, increases in stress did not predict AEs (p=0.96). Perceived stress was elevated after a CV hospitalisation (B=2.70, standard error (SE)=0.93, p=0.004) suggesting that CV hospitalisations increase stress. Subsequent analysis indicated that 24 of 38 (63%) patients showed a stress increase following hospitalisation. However, a prospective association between stress and AEs was present when accounting for prior hospitalisations (B=2.43, SE=1.23, p=0.05).

CONCLUSIONS

Sustained levels of perceived stress are associated with increased risk of AEs, and increased distress following hospitalisation occurs in many, but not all, patients with HF. Patients with chronically high stress may be an important target group for HF interventions aimed at reducing hospitalisations.

High Concordance Between Mental Stress-Induced and Adenosine-Induced Myocardial Ischemia Assessed Using SPECT in Heart Failure Patients: Hemodynamic and Biomarker Correlates

Mental stress can trigger myocardial ischemia, but the prevalence of mental stress-induced ischemia in congestive heart failure (CHF) patients is unknown. We characterized mental stress-induced and adenosine-induced changes in myocardial perfusion and neurohormonal activation in CHF patients with reduced left-ventricular function using SPECT to precisely quantify segment-level myocardial perfusion.

METHODS

Thirty-four coronary artery disease patients (mean age±SD, 62±10 y) with CHF longer than 3 mo and ejection fraction less than 40% underwent both adenosine and mental stress myocardial perfusion SPECT on consecutive days. Mental stress consisted of anger recall (anger-provoking speech) followed by subtraction of serial sevens. The presence and extent of myocardial ischemia was quantified using the conventional 17-segment model.

RESULTS

Sixty-eight percent of patients had 1 ischemic segment or more during mental stress and 81% during adenosine. On segment-by-segment analysis, perfusion with mental stress and adenosine were highly correlated. No significant differences were found between any 2 time points for B-type natriuretic peptide, tumor necrosis factor-α, IL-1b, troponin, vascular endothelin growth factor, IL-17a, matrix metallopeptidase-9, or C-reactive protein. However, endothelin-1 and IL-6 increased, and IL-10 decreased, between the stressor and 30 min after stress. Left-ventricular end diastolic dimension was 179±65 mL at rest and increased to 217±71 after mental stress and 229±86 after adenosine (P<0.01 for both). Resting end systolic volume was 129±60 mL at rest and increased to 158±66 after mental stress (P<0.05) and 171±87 after adenosine (P<0.07), with no significant differences between adenosine and mental stress. Ejection fraction was 30±12 at baseline, 29±11 with mental stress, and 28±10 with adenosine (P=not significant).

CONCLUSION

There was high concordance between ischemic perfusion defects induced by adenosine and mental stress, suggesting that mental stress is equivalent to pharmacologic stress in eliciting clinically significant myocardial perfusion defects in CHF patients. Cardiac dilatation suggests clinically important changes with both conditions. Psychosocial stressors during daily life may contribute to the ischemic burden of CHF patients with coronary artery disease.

Sex differences in platelet reactivity and cardiovascular and psychological response to mental stress in patients with stable ischemic heart disease: insights from the REMIT study

BACKGROUND

Although emotional stress is associated with ischemic heart disease (IHD) and related clinical events, sex-specific differences in the psychobiological response to mental stress have not been clearly identified.

OBJECTIVES

We aimed to study the differential psychological and cardiovascular responses to mental stress between male and female patients with stable IHD.

METHODS

Patients with stable IHD enrolled in the REMIT (Responses of Mental Stress-Induced Myocardial Ischemia to Escitalopram) study underwent psychometric assessments, transthoracic echocardiography, and platelet aggregation studies at baseline and after 3 mental stress tasks. Mental stress-induced myocardial ischemia (MSIMI) was defined as the development or worsening of regional wall motion abnormality, reduction of left ventricular ejection fraction (LVEF) ≥8% by transthoracic echocardiography, and/or ischemic ST-segment change on electrocardiogram during 1 or more of the 3 mental stress tasks.

RESULTS

In the 310 participants with known IHD (18% women, 82% men), most baseline characteristics were similar between women and men (including heart rate, blood pressure, and LVEF), although women were more likely to be nonwhite, living alone (p < 0.001), and unmarried (p < 0.001); they also had higher baseline depression and anxiety (p < 0.05). At rest, women had heightened platelet aggregation responses to serotonin (p = 0.007) and epinephrine (p = 0.004) compared with men. Following mental stress, women had more MSIMI (57% vs. 41%; p < 0.04), expressed more negative (p = 0.02) and less positive emotion (p < 0.001), and demonstrated higher collagen-stimulated platelet aggregation responses (p = 0.04) than men. Men were more likely than women to show changes in traditional physiological measures, such as blood pressure (p < 0.05) and double product.

CONCLUSIONS

In this exploratory analysis, we identified clear, measurable, and differential responses to mental stress in women and men. Further studies should test the association of sex differences in cardiovascular and platelet reactivity in response to mental stress and long-term outcomes. (Responses of Myocardial Ischemia to Escitalopram Treatment [REMIT]; NCT00574847).

Effect of escitalopram on mental stress-induced myocardial ischemia: results of the REMIT trial

IMPORTANCE

Mental stress can induce myocardial ischemia and also has been implicated in triggering cardiac events. However, pharmacological interventions aimed at reducing mental stress-induced myocardial ischemia (MSIMI) have not been well studied.

OBJECTIVE

To examine the effects of 6 weeks of escitalopram treatment vs placebo on MSIMI and other psychological stress-related biophysiological and emotional parameters.

DESIGN, SETTING, AND PARTICIPANTS

The REMIT (Responses of Mental Stress Induced Myocardial Ischemia to Escitalopram Treatment) study, a randomized, double-blind, placebo-controlled trial of patients with clinically stable coronary heart disease and laboratory-diagnosed MSIMI. Enrollment occurred from July 24, 2007, through August 24, 2011, at a tertiary medical center.

INTERVENTIONS

Eligible participants were randomized 1:1 to receive escitalopram (dose began at 5 mg/d, with titration to 20 mg/d in 3 weeks) or placebo over 6 weeks.

MAIN OUTCOMES AND MEASURES

Occurrence of MSIMI, defined as development or worsening of regional wall motion abnormality; left ventricular ejection fraction reduction of 8% or more; and/or horizontal or down-sloping ST-segment depression of 1 mm or more in 2 or more leads, lasting for 3 or more consecutive beats, during 1 or more of 3 mental stressor tasks.

RESULTS

Of 127 participants randomized to receive escitalopram (n = 64) or placebo (n = 63), 112 (88.2%) completed end point assessments (n = 56 in each group). At the end of 6 weeks, more patients taking escitalopram (34.2% [95% CI, 25.4%-43.0%]) had absence of MSIMI during the 3 mental stressor tasks compared with patients taking placebo (17.5% [95% CI, 10.4%-24.5%]), based on the unadjusted multiple imputation model for intention-to-treat analysis. A significant difference favoring escitalopram was observed (odds ratio, 2.62 [95% CI, 1.06-6.44]). Rates of exercise-induced ischemia were slightly lower at 6 weeks in the escitalopram group (45.8% [95% CI, 36.6%-55.0%]) than in patients receiving placebo (52.5% [95% CI, 43.3%-61.8%]), but this difference was not statistically significant (adjusted odds ratio; 1.24 [95% CI, 0.60-2.58]; P = .56).

CONCLUSIONS AND RELEVANCE

Among patients with stable coronary heart disease and baseline MSIMI, 6 weeks of escitalopram, compared with placebo, resulted in a lower rate of MSIMI. There was no statistically significant difference in exercise-induced ischemia. Replication of these results in multicenter settings and investigations of other medications for reducing MSIMI are needed.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00574847.

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.

QT variability during rest and exercise in patients with implantable cardioverter defibrillators and healthy controls

BACKGROUND

Increased QT Variability (QTVI) is predictive of life threatening arrhythmias in vulnerable patients. The predictive value of QTVI is based on resting ECGs, and little is known about the effect of acute exercise on QTVI. The relation between QTVI and arrhythmic vulnerability markers such as T-wave alternans (TWA) has also not been studied. This study examined the effects of exercise on QTVI and TWA in patients with arrhythmic vulnerability.

METHODS

Digitized ECGs were obtained from 47 ICD patients (43 males; age 60.9 +/- 10.1) and 23 healthy controls (18 males; age 59.7 +/- 9.5) during rest and bicycle exercise. QTVI was assessed using a previously validated algorithm and TWA was measured as both a continuous and a categorical variable based on a priori diagnostic criteria.

RESULTS

QTVI increased with exercise in ICD patients (-0.79 +/- 0.11 to 0.36 +/- 0.08, P < 0.001) and controls (-1.50 +/- 0.07 to -0.19 +/- 0.12, P < 0.001), and QTVI levels were consistently higher in ICD patients than controls during rest and exercise (P < 0.001). The magnitude of QTVI increase from baseline levels was not larger among ICD patients versus controls (P > 0.20). Among ICD patients, elevated exercise QTVI was related to lower LV ejection fraction and inducibility of ischemia (P < 0.05). QTVI at rest correlated with exercise TWA (r = 0.54, P = 0.0004).

CONCLUSIONS

QT variability increases significantly with exercise, and exercise QTVI is related to other well-documented markers of arrhythmic vulnerability, including low ejection fraction, inducible ischemia, and TWA. Resting QTVI may be useful in the risk stratification of individuals incapable of performing standard exercise protocols.

Psychobiology of depression/distress in congestive heart failure

Heart failure affects millions of Americans and new diagnosis rates are expected to almost triple over the next 30 years as our population ages. Affective disorders including clinical depression and anxiety are common in patients with congestive heart failure. Furthermore, the presence of these disorders significantly impacts quality of life, medical outcomes, and healthcare service utilization. In recent years, the literature has attempted to describe potential pathophysiologic mechanisms relating affective disorders and psychosocial stress to heart failure. Several potential mechanisms have been proposed including autonomic nervous system dysfunction, inflammation, cardiac arrhythmias, and altered platelet function. These mechanisms are reviewed in this article. Additional novel mechanisms such as mental stress-induced myocardial ischemia are also discussed.

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.

Social support predicts hemodynamic recovery from mental stress in patients with implanted defibrillators

OBJECTIVE

Emotionally stressful events appear to trigger malignant ventricular arrhythmias and myocardial infarction in cardiac patients. However, the physiological pathways linking psychological stress to arrhythmias and adverse disease outcomes remain incompletely understood. In patients with implanted cardioverter-defibrillators (ICD) we investigated the impact of emotions and social support on cardiovascular recovery from mental stress. The hypothesis tested was that psychosocial resources help to maintain adaptive hemodynamic responses to mental stress.

METHODS

In 55 ICD patients we noninvasively measured hemodynamic and autonomic parameters during two sequentially performed mental stress tests (arithmetic and anger recall tests). The cardiovascular data obtained were associated with results from well-validated psychometric self-rating tests for anxiety and depression (HADS), anger (STAXI), and perceived social support (FSozU).

RESULTS

In the rest period after mental stress application the majority of the study participants (82%) showed a rapid fall in cardiac index, arterial blood pressure, and heart rate, as well as an increase in high-frequency heart rate variability, while the remainder had no or unexpected changes in the hemodynamic parameters examined. Patients missing hemodynamic recovery in the post-stress phase reported significantly less social support than normally reacting patients (P<.05). Multivariate logistic regression models confirm that social support is an independent and significant predictor of preserved hemodynamic recovery from mental stress, even after controlling for somatic confounders (multivariate odds ratio 4.1; 95% confidence interval 1.3-12.7; P=.015).

CONCLUSIONS

Our data indicate that in ICD patients better perceived social support is associated with a more pronounced hemodynamic recovery after mental stress.

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.

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.

Mental stress provokes ischemia in coronary artery disease subjects without exercise- or adenosine-induced ischemia

OBJECTIVES

The purpose of this study was to investigate the possibility that some patients with coronary artery disease (CAD) but negative exercise or chemical stress test results might have mental stress-induced ischemia. The study population consisted solely of those with negative test results.

BACKGROUND

Mental stress-induced ischemia has been reported in 20% to 70% of CAD subjects with exercise-induced ischemia. Because mechanisms of exercise and mental stress-induced ischemia may differ, we studied whether mental stress would produce ischemia in a proportion of subjects with CAD who have no inducible ischemia with exercise or pharmacologic tests.

METHODS

Twenty-one subjects (14 men, 7 women) with a mean age of 67 years and with a documented history of CAD were studied. All subjects had a recent negative nuclear stress test result (exercise or chemical). Subjects completed a speaking task involving role playing a difficult interpersonal situation. A total of 30 mCi 99mTc-sestamibi was injected at one minute into the speech, and imaging was started 40 min later. A resting image obtained within one week was compared with the stress image. Images were analyzed for number and severity of perfusion defects. The summed difference score based on the difference between summed stress and rest scores was calculated. Severity was assessed using a semiquantitative scoring method from zero to four.

RESULTS

Six of 21 (29%) subjects demonstrated reversible ischemia (summed difference score > or =3) with mental stress. No subject had chest pain or electrocardiographic changes during the stressor. Mean systolic and diastolic blood pressure and heart rate all increased between resting and times of peak stress.

CONCLUSIONS

Mental stress may produce ischemia in some subjects with CAD and negative exercise or chemical nuclear stress test results.