Lecture 4: Stress and cardiovascular disease Flashcards
How can psychological conditions influence myocardial infarction and cardiac death?
- Can be trigged by emotional distress
- Vulnerability determined by CAD, myocardial damage and chronic psychiatric, psychological and social conditions which can enhance the likelihood of emotion-related triggers
Phases of acute coronary syndromes
- Gradual subclinical disease progression
- Vulnerable disease stage
- Acute coronary syndromes
- Cardiac symptoms like chest pain and angina occur later in the disease process
What are the 3 categories of classification of cardiovascular risk factors?
- Acute psychological risk factors like outbursts of anger, mental activity and acute distress can trigger within 1 hour
- Episodic psychologic risk factors which lasts from several weeks to two years which can be depression, exhaustion, job loss
- Chronic psychological risk factors which can increase progression of CAD like personality traits and socioenvironmental factors
What is the role of chronic psychologic risk factors?
Chronic psychologic risk factors linked to increased reactivity to acute stressors and greater risk of development of episodic risk factors. Greater emotional and biologic response to acute stressors
What is the definition of psychological distress?
Negative internal state of the individual that is dependent on interpretation or appraisal of threat, harm or demand. Stress has some definitional problems but distress is used to indicate the reaction to stressors. It incorporates a large portion of predictive values of cardiovascular risk like depression, anxiety, hostility and low social support. Severe and uncontrollable distress can result in clinical and subclinical states which have negative affect
How can psychological distress be evaluated?
By environmental precipitants, and factors that can increase vulnerability to these events as well as psychological and social factors which act as buffers (social support, coping resources, optimism). To detect this distress can lead to referral and intervention
What is the role of acute distress in triggering cardiac events?
- potential trigger of acute coronary syndromes and cardiac arrhythmias
- prolonged and repeated exposures to short term stress can lead to more cardiac and vascular disease progression
- acute coronary syndromes preceded by acute trigger
- increase in central and ANS activity is linked to psychological events which result in cardiac pathologies
- acute distress plays a role in clinical syndromes with no anatomical or structural disease
What is the difference between panic disorder and non-cardiac chest pain?
- Can be complicated
- Angina can be the result of abnormal microvascular vessels with normal coronary arteries
Cases which highlight importance of psychological distress as a trigger of acute coronary syndromes
- development of left ventricular dysfunction after suicide hanging due to intense emotions and physical challenge
- spouse found to die after other one dies due to heart causes-> acute coronary occlusion due to structure mental challenge task during coronary angiography
- anger preceded patients in 2 hours preceding the MI with a high relative risk
Myocardial ischemia
This is when cardiac demand exceeds coronary blood supply to heart muscle, causing infarctions. Exercise and psychologic distress can induce transient myocardial ischemia by increasing cardia demand. Psychologic stress can cause decreased supply due to constriction.
Features of ischemia induced by acute psychological distress
- occurs in 40-70% of CAD patients with exercise-inducible ischemia
- not detectable by ECG ST-segment changes
- asymptomatic
- occurs at lower heart rates and similar blood pressure
- linked to lower ischemic thresholds during exercise testing and monitoring
- more than two fold risk of negative CVD outcomes
Cardiac arrhythmias
- arrhythmic vulnerability can be linked to myocardial ischemia
- severe to moderate distress was linked to ventricular fibrillation
- more patients with defibrillators after 9/11, but media could have played a role too
- acute mental stress induced by angerl recall and mental arithmetic was linked to increases in T-wave alterations with defibrillator.
- These T-waves were predictive of future arrhythmias
- mental arithmetic can induce prolongation or QT interval
Acute heart failure
Lots of overlap of acute heart failure with MI, but less evidence.
Takotsubo syndrome clinical characteristics
- left ventricular dysfunction
- apical ballooning
- minimal CAD
- limited cardiac damage
- develops in post-menopausal women
- catecholamine increase plays a role
What is different about takotsubo syndrome?
Can result to normal or near normal LV function. The treatments are patient education, counselling, pharmacologic therapy. There can be substantial cardiac responses to distress like LV function impaired, life-threatening arrhythmias with no CAD.
What are most common psychological risk factors in cardiology?
Depression and exhaustion which could be due to psychological distress (includes marital distress, natural disaster, job loss and job strain). MI is associated with higher prevalence in work stress, home stress, financial stress, major life stress, lower locus of control and more depression (retrospective bias could play a role in results to find an explanation). But high predictive value of distress for adverse CVD outcomes
What can precipitate depressive episodes?
- psychologic reactions to having a life threatening disease with symptoms, functional limitations, CVD changes that can alter the CNS
- mild to moderate episodes linked to adverse life events but not for severe episodes
- dysfunctional cognitions/maladaptive responses to loss and health play a role
- functional severity, social factors and biological all play a role
Link between depression and cardiology
It predicts the first and recurrent MI and cardiac death. Untreated depression can significantly increase the risk of cardiac events.
Fatigue and lack of energy, irritability more often observed in cardiac patients than other symptoms like sadness, guilt, low self-esteem. Prior diagnoses seen to be stronger predictor of post-MI mortality than during.
What is the role of fatigue in acute coronary syndromes?
Known as vital exhaustion which is a lack of energy, increased irritability and demoralization. Vital is seen as the long-term consequences of this condition on daily life functioning. Depression and exhaustion seen as not fully overlapping conditions. Somatic depressive symptoms seen as better predictors of MI than cognitive-affective depressive symptoms.
What has recent evidence found?
There is an association between depressive symptoms and endothelial dysfunction in peripheral arteries but not in coronary arteries. Depression and exhaustion is not a remain of an underlying disease. The predictive value also decreases when the follow up is more than 2 years. Episodic risk factors may not be long enough to sustain and atherosclerotic process and plaque activation could be involved in risk
What are some examples of chronic distress?
Includes personality traits like hostility, type A behaviour pattern, type D personality and trait anxiety. They have genetic underpinnings and could promote the onset of atherosclerosis in young adulthood through SNS processes, health behaviours and CAD risk factors.
What is the role of hostility and type A behaviour?
Hostility seen as toxic side of type A behaviour, which includes cynical mistrust, aggression. Association with severity of underlying CHD. Stronger in younger men than older men but predictive value is inconsistent.
What is the role of type D personality?
Seen as vulnerability factor that accounts for the predictive value of depression, anxiety, trait anger. Seen as inclination to experience negative emotions and social inhibition. Can adversely affect CVD outcomes but more research needed. Predictive value of type D personality from depression has been noted.
PTSD as a risk factor
Seen as chronic risk factor and predictive of increased health use, adverse CVD risk factors, increased CVD morbidity. Could be related to underlying vulnerabilities like rumination about adverse events or other biobehavioural processes.
What is the neurohormonal pathway?
Distress is linked to SAM activation, HPA homrones, increased SNS activity and decreased PNS activity. Depression involves inactivation of CRH system and reduced norepinephrine levels and reduced hemodynamic reactivity to challenge tasks. Leads to disruption of homeostasis which can lead to CVD progression
What is the inflammation and psychologic distress pathway?
Immunosuppressive correlates of prolonged distress is similar to depression. Increased levels of antibody to herpes viruses including CMV. Immune system correlates of distress is linked to a higher risk for acute coronary syndromes. These could promote CVD by enhancing macrophage and lipid deposits. Inflammation can lead to greater plaques and plaque rupture-> coronary syndromes
What is the significance of CVD
Leading cause of death globally, responsible for 32% of deaths. CVD is leading cause of death in women, while cancer is the overall leading cause of death. In US is leading cause of death
What has been found to be a trigger of acute myocardial infarction?
Many reported anger 2 hours before the MI, which increases relative risk to 2.3
Overview of CVD disease (do not learn)
Consists of heart to pump blood, blood vessels to supply tissues with oxygen and nutrients. Pumps oxygenated blood out of LV and pumps used blood through lungs through RV. Needs blood supply from coronary arteries to contract. Types of CVD: CHD (CAD/MI), heart failure, valve, arrhythmias, stroke. CHD caused by narrowing of coronary artery and tissue damage develops. Risk factors include: hypertension, diabetes, elevated lipids, smoking, overweight, psychosocial, age, sex, genetic factors
How can psychosocial risk factors for CAD be categorized?
- acute factors (triggers)
- episodic factors (transient and recurring)
- chronic factors
Associations with disease progression depend on the severity of the underlying coronary disease. Most of these risk factors are sub-threshold and don’t meet diagnostic criteria for disorders
Psychological distress definition
negative internal state of the individual that is dependent on interpretation or appraisal of threat, harm, or demand. 2 types:
- eustress which is evoked by positive emotions or events
- distress is evoked by negative feelings and events
Variables affecting stress responses
Time
Control
Individual Vulnerability
How are psychological risk factors linked to CAD outcome?
Chronic (low SES, personality, hostility, type D, low optimism) can result in early CAD so T cell and macrophage recruitment-> intermediate CAD like foam cells and minimal stenosis. Episodic (depression, exhaustion) come in between severe CAD (lumen narrowing) and acute coronary syndromes. Acute risk factors like anger and mental activity and directly influence acute coronary syndromes
What are the acute psychological factors?
Anger-> disaster like earthquake
Anxiety-> acts of war/aggression
Acute distress-> major public events (sports, elections)
What are the mechanisms underlying mental stress ischaemia?
Decreased cardiac supply
which leads to narrowing coronary arteries. Leads to increased cardiac demand (hemodymanic reactivity) and affects blood pressure, heart rate, contractility.
Risks of ischaemia
Highest for frustration, sadness, tension, much lower for happiness.
Multiple mental stress stimuli and exercise lead to provocation like wall motion, perfusion, ECG and chest pain
Heart rate variability in ischemia
- lower for those with ischemia, and lowest for those with high mental activity compared to low mental activity
- higher heart rate for those with ischemia, highest for those with high mental activity
Link between mental issues and ischaemia
CAD and panic disorder led to higher inducibility of ischemia. Coronary constriction common with acute mental stress led to a reduction in supply. Those with higher blood pressure response to mental stress had a lower diameter response.
Features of mental stress-induced ischaemia
Observed in 30%-70% of patients with coronary artery disease
Reduced coronary supply plays an important role
-Mental stress-induced ischemia is associated with poor prognosis and increased risk of mortality
- Asymptomatic and goes undetected
- Linked to lower heart rate
- mixed reproducibility in lab
Tak-tsubo cardiomyopathy featues
-ECG suggesting acute myocardial infarction
-Apical ballooning or other major ventricular dysfunction
-Chest pain/dyspnea, pulmonary edema, cardiogenic shock
-Short-term recoveryof LV function typically fast; long-term prognosis similar to myocardial infarction
But also:
-Minimal coronary artery disease
-Often triggered by emotional or physical distress (≈50% each)
- High (supraphysiologic) circulating catecholamines on admission
- ≈80% female, mostly post-menopausal (mean age 63 yr)
Episodic psychological factors
Include MDD, exhaustion, burn-out and transient and recurring. Those with general sustained stress at work home or both, severe financial stress and stressful life events in the past year and depression were all linked with MI higher prevalence
How does CVD increase the likelihood of depression?
Symptoms (chest pain, shortness of breath, fatigue, more irritability)
Functional capacity (exercise tolerance)
Biological consequences (inflammation, CNS changes)
Existential questions related to a life-threatening disease
Linked to adverse health behaviours like physical inactivity, poor diet
(Heart structure and function per se do not strongly predict depression)
Depression not a direct by-product of underlying CAD or heart problem
Depression also increases the risk of CVD and mortality
Depression risk factors
Life stressors (particularly in mild-moderate depressive episodes)
Negative cognitive bias
Maladaptive response to loss (of a significant other or “object”)
Genetic vulnerability
Biobehavioural mechanisms
Central Nervous System (SAM, HPA)
Autonomic nervous system (parasympathetic & sympathetic)
Blood clot formation (coagulation & reduced fibrinolysis)
Inflammation & Immune dysregulation
What is the role of C-Reactive protein?
- higher amounts are linked to more adverse outcomes in CVD
- those with depression have higher concentrations of CRP and IL-6, both markers of chronic inflammation
How does depression lead to ACD?
Depressive symptoms-> CNS changes, neurohormones, sympathetic/parasympathetic balance shift-> micro-organism antibodies increase, immune suppression can result in gradual CAD progression. Proinflammatory cytokines increase which leads to plaque activation, prothrombotic state and acute coronary syndromes. Depressive symptoms and CNS changes both bidirectional
Effects of psychological factors on disease risk?
Psychological factors
-> biological effects (CNS, ANS, endrocrine, homeostasis)
-> behavioural effects (health behaviours, symptom reporting, seeking medical care)
Both of which result in disease outcome
Main conclusions
- Acute mental stress can induce myocardial ischemia in patients with CAD and is a significant precipitant (trigger?) of cardiac events
- Depression linked to increased CVD risk, bidirectional
- acute mental stress and depression linked with higher inflammation markers but inconsistent with CAD patients and small effect sizes but acute stress is higher in CAD patients
- future studies needed to: identify high-risk sub-groups and create interventions and develop models of mutually reinforcing risk factors
