Rethinking Bereavement: How Stress and Depression Can Lead to “Broken Heart Syndrome”
Bill Schutt on the Surprising, Intimate Connection Between the Heart and the Brain
While most beliefs about the heart’s emotional and spiritual importance exist outside the realm of modern scientific proof, recent research into one particular form of coronary disease has found an indication that hearts and minds are connected after all—if not in the way ancient or alternative medicine suggest.
In 1990 cardiac researchers in Japan studied a group of 30 patients, each of whom had entered the hospital complaining of chest pains and shortness of breath. When tested initially, they all showed symptoms resembling those of a heart attack: dysfunction of the left ventricle, as well as abnormal electrocardiograms (ECGs), graphical representations of the electrical activity of the heart. Upon examination, however, the doctors found no signs of narrowing in the coronary arteries, a symptom typically found in patients suffering from an infarct (i.e., tissue death due to insufficient blood flow). In fact, the majority of the patients showed no signs of heart disease at all.
Even odder were the results of another test performed to evaluate the condition of the left ventricle. After inserting cardiac catheters to inject dye into the ventricle (thank you, Werner Forssmann!), the physicians took x-rays as the patients’ hearts went through their cycles of filling and emptying. When examining the resulting ventriculograms, the researchers were struck by the fact that as the left ventricle finished contracting, it took on a weird shape: narrow at the top and ballooning out at the bottom.
It reminded the Japanese researchers of the octopus traps, or tako-tsubo (“octopus” plus “pot”), that were used by local fishermen. Then, in yet another departure from the typical outcomes of a myocardial infarction, the majority of the patients in question saw their heart conditions resolve during the following three to six months. Apparently, whatever damage had occurred was completely reversible, which made this condition unique among diseases of the cardiac muscle, aka cardiomyopathies.
Since the initial studies of what has become known as Takotsubo syndrome, researchers have made considerable strides in their understanding of who experiences this strange malady and what triggers it. Interestingly, 90 percent of those who suffer from Takotsubo syndrome are postmenopausal women, and most of them have recently experienced acute physical or emotional stress, some of it as severe as surviving a recent suicide attempt. Many others had suffered grief over the death of a loved one. The relationship between bereavement and Takotsubo syndrome has led to an alternative name for the condition: broken heart syndrome.
The workings of Takotsubo syndrome actually make a great deal of sense. During highly emotional or stressful situations, the body’s nervous system (specifically the sympathetic division of the autonomic nervous system, which regulates unconscious body systems) floods the circulatory system with stress hormones—the fight-or-flight response. These chemical messengers prepare the body to deal with real or perceived threats by managing physiological functions like heart rate, blood pressure, and breathing rate. In normal situations, this sympathetic response gets shut down when the threat passes or when emotions subside.
But in patients with Takotsubo syndrome, researchers theorize that there is decreased communication between the brain regions that process emotions and the autonomic nervous system. This causes the sympathetic nervous system to overrespond by continuing its outpouring of stress hormones—the overabundance of which leads to potentially serious cardiovascular problems. These can include spasming of the coronary arteries and their microscopic branches, a phenomenon that could explain the left ventricular dysfunction and chest pains observed in Takotsubo patients.
There are, however, unanswered questions regarding the condition. For example, it remains unclear why the left ventricle takes on its peculiar octopus-trap shape. It’s also unknown whether the brain’s overproduction of stress hormones is caused by the emotional trauma the patient suffered or whether the brain dysfunction responsible for the overstimulation of the sympathetic nervous system was already present, thus making that person more susceptible to Takotsubo syndrome.
Uncertainties aside, the condition serves as a dramatic example of the intimate connection between the heart and the brain—evidence that emotions like grief can lead to physical changes in the heart—in this case, changes of a temporary nature. But this heart/brain connection is actually a two-way street, since it is also clear that a damaged heart can lead to emotional dysfunction.
I spoke to cardiologist and University of Wisconsin professor emeritus Patrick McBride, a leading expert on cardiovascular risk factors. I was interested in learning why stress and depression negatively affect the heart and how the situation might be countered. He emphasized that due to the number of confounding factors, the link is extremely difficult to research. For example, when somebody’s spouse dies, it is quite common for the survivor to end up in the hospital with a heart attack. But while the pattern is clear, the reasons for it are less so.
McBride reviewed the body’s fight-or-flight response with me, the same system which kicks in during Takotsubo syndrome. While its cocktail of adrenaline, cortisol, and other stress-related chemicals is useful in managing physical threats, it can be counterproductive when it comes to emotions. When someone is under chronic stress, as they might be if a loved one had passed away after a long illness, those hormones may circulate so frequently that they can irritate the heart and blood vessels, damaging their inner lining, or endothelium. While this single layer of cells was until recently, thought to be relatively inert, it actually has an endocrine function. Over the past two decades, researchers have shown that the endothelium releases its own set of hormones into the blood.This heart/brain connection is actually a two-way street, since it is also clear that a damaged heart can lead to emotional dysfunction.
“Second to second and minute to minute, the endothelium is responding to our chemical environment,” McBride told me. “If muscles need more oxygen, the chemicals released by the endothelium dilate the blood vessels that supply them, while contracting the blood vessels elsewhere.”
When the endothelium becomes inflamed, the damaged cells also release chemicals like histamine, bradykinin, and cytokines (a broad category of small proteins also released by cells of the immune system). One result is that the blood vessels become more porous, and they leak plasma into the tissues surrounding them. This leads to the characteristic swelling, redness, and pain that we associate with inflammation. Meanwhile, the chemicals that have been released signal the body’s repair team to show up and get to work.
This process is helpful when inflammation is acute, but not so much when the condition becomes chronic. McBride compared the constant presence of inflammatory chemicals to rubbing your skin until it becomes raw. What’s more, as the lining of blood vessels becomes more porous during prolonged inflammation, chemicals in the blood can become modified, making them behave differently. One such change occurs when LDL cholesterol undergoes the process of oxidation, becoming Ox-LDL, a substance known to be involved in the formation of atherosclerotic plaques. MacBride likened Ox-LDL to bacon grease left in a pan.
Things can get even worse if the person in question already has atherosclerotic plaques, since chronic inflammation can cause the vessel’s inner lining to crack open. As the body’s repair crew rushes in to plug the damage, a blood clot forms. Usually clotting is a good thing—an intricate cascade of so-called hemostatic chemical reactions whose fibrous final product (the clot) can effectively halt blood loss from a ruptured vessel. Here, though, the feces hits the fan if a piece of the clot breaks off and flows downstream, where it can get stuck in an increasingly small vessel like a coronary artery or an artery supplying part of the brain. This can lead to a heart attack or a stroke, respectively.
Now, somewhat more well versed on the relationship between stress and the heart, I decided to change course with McBride, seeking to explore the methods currently being used to counteract the heart-unhealthy effects of stress.
Surprisingly, McBride led off with spirituality.
“It’s very clear to me that people with spiritual lives do better—and that’s research-driven.” When people aren’t afraid of their own mortality, he explained, they have better outcomes.
His claim, however, is controversial, since for every study pointing to the benefits of religious activity as it relates to health, there are critics who claim that even the best of these studies were faulty, because they lacked controls or did not consider covariables like age, sex, ethnicity, education, behavior (like smoking and alcohol consumption), and socioeconomic and health status, before reaching their conclusions.
The fact remains, however, that patients who receive social support or are in strong relationships are more likely to have better outcomes. “People who are lonely or widowed have worse outcomes,” McBride said.
Over the past four decades, McBride and his cardiac rehab colleagues have been working to address the high rate of depression that follows heart attacks. The reason for their efforts is that, like other types of acute stress, depression aggravates circulatory tissues. In combination with the heart disease that led to the event, this can have deadly consequences. McBride told me that currently, one in every two to three recovering patients is likely to suffer from the mood disorder. To address this problem, as part of their protocol McBride’s team screens every patient that has had a heart-related event for depression, regardless of whether the event was the placing of a stent, bypass surgery, or a heart attack. As a result, the medical team at the University of Wisconsin’s Preventive Cardiology Clinic has had psychologists and therapists on staff since the 1980s and has been championing a mindfulness program since 1994.
Mindfulness is a therapeutic technique with its roots in Buddhist meditation. When practicing mindfulness, one attempts to focus one’s awareness of thoughts, feelings, and bodily sensations on the present moment, rather than rehashing the past or worrying about the future. The technique also emphasizes acceptance of thoughts and feelings without judging them, helping practitioners understand that there is no “right way” or “wrong way” to feel at any given moment. Since the late 1970s, mindfulness has become a popular stress-management program, and it is commonly employed in prisons, hospitals, and recently, in schools, where anxiety among children has become a serious concern.
McBride told me that initially the professionals running his cardio rehab program referred to these mindfulness classes as “stress management” or “stress reduction.”
“All the guys would show up,” he said.
But then the staff started calling it “mindfulness meditation” and bringing in elements of yoga and tai chi. “And men would never show up. It was just too Eastern for these Western dudes.”
I laughed. “How’d you fix that?”
“We went back to calling it ‘stress management,’ and the men showed up in droves.”
From PUMP: A Natural History of the Heart © 2021 by Bill Schutt. Reprinted by permission of Algonquin Books of Chapel Hill. All rights reserved.