This is how stress can cause heart attacks

Heart attacks are the leading cause of death worldwide. It is a type of coronary accident related to lifestyle; in particular, the appearance of heart attacks is directly influenced by sustained stress and unhealthy habits.

In this article we will analyze the mechanisms by which stress can make heart attacks easier. For this, it is necessary that we pause previously in the definition of these two concepts.

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What is stress?

We can define stress as a set of physiological responses that occur when stimuli or situations that the body perceives as threatening or demanding.

These body reactions are nonspecific and stereotyped; This means that they do not depend on a specific type of environmental stimulation and that they are very similar regardless of the causes that cause them.

Physiological stress responses depend on the activation of the hypothalamic-pituitary-adrenal axis and the autonomic nervous system. Short-term effects include an increase in heart rate and consumption of stored energy, as well as other signs of physical arousal.

The physiologist Hans Selye described three phases of stress in his model of General Adjustment Syndrome. During the alarm phase, the body recognizes the stressor and mobilizes to deal with it; if the stress still persists, we move on to the resistance phase, in which the activation decreases a little to be able to maintain itself in the long term.

When the body has consumed its resources the third phase appears, called "exhaustion" and characterized by the reappearance of the intense symptoms typical of the alarm phase. Although the advanced phases of the stress response damage the body, the alterations usually disappear after a period of rest during which the person generates new energy reserves.

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Consequences of stress

When stress is maintained in a sustained way, it causes what we know as stress syndrome, consistent in the appearance of peptic ulcer, the increase in the size of the adrenal gland and the decrease of the thymus. These alterations are related to massive glucocorticoid secretion and suppression of the immune response, which facilitates the development of diseases.

Today's increasingly stressful lifestyle has led to a clear increase in the prevalence of blood circulation disorders, such as heart attacks and hypertension. Having high blood pressure increases the probability that atherosclerotic plaques will accumulate, and therefore that cardiovascular accidents will occur.

There are also many psychological symptoms that can be influenced by stress: anxiety, irritability, apathy, sadness, emotional instability... Among stress-related disorders highlight anxiety and depression which, like cardiovascular disorders, are considered lifestyle diseases.

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Definition of heart attack

Heart attacks are the leading cause of death worldwide, according to the World Health Organization, and their frequency continues to grow; while in 1990 they accounted for 12% of deaths, in 2013 this figure was close to 17%.

The infarction consists of the death (or necrosis) of part of the tissue of an organ. Necrosis usually occurs as consequence of the obstruction of the artery that supplies it.

When necrotic tissue is found in the musculature of the heart, we speak of myocardial infarction. Heart attacks can also occur in other organs; in addition to the heart, the most common are the brain, kidneys and intestine.

If the accident takes place in the kidneys we speak of renal infarction, while if they occur in the intestine the correct term is “mesenteric intestinal infarction”. Cerebral infarcts are known as "cerebrovascular accidents" or “cerebrovascular accidents”.

Arterial obstruction is usually due to the accumulation of atheroma plaques (or atherosclerosis) but It can also be a consequence of hernias, the presence of tumors or the deformation of the organ.

Among the most relevant factors that predispose to the appearance of heart attacks are tobacco and alcohol consumption, obesity, sedentary lifestyle, the diabetes and elevated cholesterol levels. They also occur more frequently in men, in people over 40 years of age, and in those with a family history of cardiovascular disorder.

How does stress cause heart attacks?

The appearance of heart attacks as a result of stress is due to the conjunction of a series of interrelated causal mechanisms. Specifically, scientific research has linked heart attacks to increased levels of cortisol and hyperresponsiveness of the amygdala.

Cortisol is a steroid hormone It is produced in the adrenal gland and is released in response to stressful conditions. Although it is essential for the body to consume energy, excessive and continued secretion of cortisol can inflame the arteries, narrowing them and making it easier for them to block.

The tonsils are two brain structures that are located in the temporal lobes and are involved in the learning emotional responses, including those of fear, anxiety and stress. When stress levels are high for much of the time, neurons in the amygdala learn by classical conditioning to provoke stress responses to stimuli that do not really involve a threat.

Therefore, continuous stress in itself negatively affects the cardiovascular system, but also facilitates that the amygdala associates the fear response with harmless stimuli. This produces a vicious cycle in which stress causes more stress, increasing the risk of heart attacks and other circulatory problems.

However, the continued practice of physical and cognitive relaxation exercises can help the body to stop emitting stress responses at inappropriate times. Scientific research particularly supports slow deep breathing and progressive muscle relaxation procedures.

Bibliographic references:

• Ressler, K. J. (2010). Amygdala Activity, Fear, and Anxiety: Modulation by Stress. Biological Psychiatry, 67 (12); 1117 - 1119.

• Tawakol, A. et al. (2017). Relation between resting amygdalar activity and cardiovascular events: a longitudinal and cohort study. The Lancet, 389 (10071); 834 - 845.