Heart diseases – stress to blame?

The heart is traditionally regarded as a barometer of emotions and experiences. This heart is shattered by unhappiness, trembles from delight, and freezes from fear. Rather strange metaphors to describe the reactions of a muscular organ whose main task is to pump blood. But scientific research and medical observations show that strong emotions do affect the cardiovascular system and can even affect it physically.

Can acute stress be dangerous?

When faced with bad news or accusations, the hero of the film grabs his chest with his hands and grimaces in pain – a classic scene of a heart attack caused by stress, which became a meme before the term even existed. How true is this cliché?

Donald Edmondson and his colleagues in 2013 examined whether strong, violent emotions are often the cause of heart attacks. At the same time, determine how credible it is that negative experiences like grief can increase the chances of a “heart catastrophe” by more than 20 times. Based on a review of scientific papers on this topic, it appears that these alarming findings are derived from studies that used surveys of patients who recently suffered a heart attack or sudden cardiac arrest instead of measuring objective markers of stress. People tend to retroactively project negative experiences onto the past. The link between emotional distress and serious heart problems is confirmed in only 2-3% of those affected. Thus, the likelihood of your “heartbreaking” experiences is not that high.

Despite this, acute stress is not harmless to the heart, according to cardiologist Dmitry Sumin. There are two cases in which strong emotions can threaten heart health. The first is the broken heart syndrome, which was first discovered by Japanese scientists in the 1990s. It really feels like a heart attack (pressing, constricting & burning chest pain, shortness of breath, dizziness). But it is not caused by blockage of the coronary arteries or tissue damage, but rather by an abnormal response of the heart to adrenaline, which is released into the bloodstream during stressful situations. In such a situation, the left ventricle (the main pump of the heart) stops contracting normally and swells like a pear. The condition was therefore named Takotsubo cardiomyopathy after the Japanese pot for catching octopuses, with a wide bottom and a narrow neck.

Why does this reaction occur? The most recent theory associates it with two molecules, microRNA-16 and microRNA-26a, which are linked with depression, anxiety, and increased stress levels. These compounds are found in the blood of those suffering from broken heart syndrome and have also caused the characteristic swelling of the left ventricle in laboratory experiments. It sounds scary, but after such an attack, the heart often recovers fully, and the risk of death does not exceed 1%. It isn’t enough to survive a bad relationship to join the Heartbreak Club. It is a relatively rare condition. According to medical statistics, it accounts for no more than 2% of hospitalizations for suspected heart attacks.

The second case is stress associated with cardiovascular disease that has already developed. In ischemia, for instance, the startle response can indeed be dangerous. Therefore, strong emotions are strongly associated in the public consciousness with a heart attack. However, do not confuse the effect with the cause. In terms of its effect on the body, stress reacts in a similar manner to a sharp physical exertion. Being scared is like running up a couple of flights of stairs. In response to a threat, the body instantly mobilizes to meet it fully armed. It is the heart that bears the majority of the mechanical load in this case. Heart has to pump a lot of blood to the muscles so they can fight or flee. In this tense moment, heart problems emerge that remained hidden under less tense circumstances. Moreover, the problems that are found during emotional stress are more related to the condition of the blood vessels than to the heart.

Oxygen is necessary for the heart. Stress increases this need dramatically. Due to atherosclerosis or thrombosis, damaged vessels cannot meet the increased demand. In an oxygen-deficient environment, the heart muscle cells begin to die off, resulting in myocardial infarction. It is not acute stress that damages the vessels.

Destructive potential of stress

Technically, chronic stress affects your body in the same way as acute stress. The only difference is the reduced intensity of the stress reaction: blood rushes to the muscles a little less, blood sugar does not rise sharply, blood pressure does not rise, and the heart accelerates at the speed of an old minivan, not the latest Tesla.

In acute stress, the body rapidly goes through two initial stages (anxiety and resistance) before it begins to suppress its own stress response. Chronic stress is different. While many body systems are under load, the voltage does not reach the critical level that triggers the automatic braking system. Thus, the transition to the exhaustion stage is imperceptible.

Chronic stress isn’t a single episode but a recurring process. The typical examples are friction within the family, relationship problems with children and ex-spouses after the divorce, and difficulties at work. These problems often lack not just a clear timeframe, but also an unambiguous solution. They require constant attention and become part of our daily routine. It is why coping strategies are so important for chronic stress – what we do consistently to cope with it. However, even the most dangerous of these strategies provides a real opportunity to temporarily relieve tension. For example, stress can be “seized” on junk food, “soaked” with alcohol, “smoked” by smoking, or overcome with excessive work, sacrificing rest and sleep. Negative coping strategies are the biggest enemies of the heart and blood vessels. Essentially, chronic stress is not dangerous in and of itself, but only because of how we cope with it? Several years ago, the answer would have been yes. However, now we know that things are more complicated.

An interesting study appeared in The Lancet in 2017. Scientists tested two groups of subjects (one with atherosclerosis, the other with post-traumatic stress disorder). The team compared several indicators, including the excitability of the amygdala (the brain structure involved in the primary response to stressors), the activity of the bone marrow (our main organ involved in hematopoiesis), markers of inflammation in the blood, and the state of the cardiovascular system. It turned out that overactive amygdalas cause the bone marrow to produce more leukocytes, which can lead to inflammation of the endothelium (the inner lining of blood vessels), which in turn leads to damage to the vascular wall, angina pectoris and blood clots. Therefore, chronic stress directly damages blood vessels. 

Is there a way to detect an overactive amygdala without positron emission tomography? All you need to do is pass an anxiety test (The Hospital Anxiety and Depression Scale (HADS)).

How to help your heart cope with stress

The three main areas are learning to control the immediate response to stress, reducing the number of stressors in life, and adjusting long-term adaptations.

Taking control of the amygdala. This is difficult to accomplish. The amygdala is part of the limbic system of the brain, which is uncontrollable and operates like a stimulus-response automaton. It can only be “tamed” by the brain itself, if you give it a stimulus at the moment of stress, in response to which it will automatically calm down. These are the three easiest ways.

• Rinse your face with cold water. You will trigger the diving reflex common to mammals. In the moment that your brain imagines you are diving, you will naturally slow your heart rate and hold your breath in order to conserve air, as well as constrict peripheral vessels to redirect blood from your muscles to your internal organs, thus relieving stress on your heart.
• Get a breath. Because the heart rate increases during stress, there is a feeling of lack of oxygen, which increases anxiety and excites the amygdala. Breathe in and out through your nose for five to six seconds without pausing.
• Light the lamp. At night or in dim light, the amygdala is most active. Bright lighting reduces arousal in the amygdala and simultaneously enhances its “functional connection” with ventromedial prefrontal cortex, the area that is responsible for conscious emotional control.

Controlling stress triggers. Getting rid of all stressors from life is an impossible goal. However, the amygdala can be activated in two ways. Additionally to external factors, which are often beyond our control, she can be roused by our own internal signals, such as disturbing thoughts. Controlling them is possible. As an example, when you lose your profitable job you automatically perceive it as a disaster. “However, if you start focusing on new opportunities and impressions – on the fact that you are finally able to go where you have always dreamed of going, then the stress level will significantly decrease,” states Dmitry. Why does it work this way?

In the moments of excitement, instead of panicky thoughts of “everything has been lost” or “I will be fired”, try focusing on the realization that you are stressed. As a result, the center of activity will shift from the amygdala to the prefrontal cortex, responsible for control and planning.

Change your focus from a stressful problem to any other problem that requires mental energy by using willpower. It may seem difficult at first, but studies show it activates the prefrontal cortex and slows down amygdala activity.

Correcting strategy. The eight universal ways to cope with stress are confrontation, distancing, self-control, suppressing emotions, seeking social support, running away from a problem, planning a solution, re-evaluating and accepting responsibility. The peculiarity of these options is that within each of them, positive and negative outcomes are possible. Getting away from a problem can be achieved by smoking a pack of cigarettes or going for a run. In order to distance yourself from the problem, you can procrastinate, delaying the solution and building up latent anxiety, or meditate. You will need to consult a specialist to correct them. Here, Cognitive Behavioral Therapy has worked well. It’s better to do it beforehand. “Many patients regret not starting to work on reducing their stress levels earlier during rehabilitation after a stroke or heart attack,” says Dmitry Sumin.