Heart--A History Read online

  The twelfth-century Christian mystic Hildegard of Bingen once wrote, “The soul sits at the center of the heart, as though in a house.” In many ways, the heart does resemble a house. It is divided into multiple chambers, separated by doors. The walls have a characteristic texture. The house is old, designed over many millennia. Hidden from view are the wires and pipes that keep it functioning. And though the house has no intrinsic meaning, it carries meaning because of the meanings we attribute to it. The heart was once considered the center of human action and thought—the source of courage, desire, ambition, and love. Even if those connotations are outdated, they are still deeply relevant to how we think about this organ and how it shapes our lives.

  PART I

  Metaphor

  Separation, Edvard Munch, 1896, oil on canvas, 96.5 × 127 cm (Munch Museum, Oslo [MM M 00024]; photograph © Munch Museum)

  1

  A Small Heart

  You can die of a broken heart—it’s scientific fact—and my heart has been breaking since that very first day we met. I can feel it now, aching deep behind my rib cage the way it does every time we’re together, beating a desperate rhythm: Love me. Love me. Love me.

  —Abby McDonald, Getting Over Garrett Delaney (2012)

  When I was fifteen, I had to do a research project for my high school biology class. I decided to measure the electrical signal from the heart of a live frog. To do the experiment, I was going to have to pith the animal—sever its spinal cord while it was still alive, thus paralyzing it—before cutting it open. I borrowed an oscilloscope to measure current, a voltage amplifier, and some red and black electrodes. My science teacher, Mr. Crandall, said it was an impressive project for a high school junior.

  But first I had to collect some frogs. With a fishing net in one hand and my bicycle handlebars in the other, I set off for the woods near my house in Southern California. It was a late Friday afternoon in early spring, and birds were singing petulantly. The road was wet. My bicycle tires made gritty sounds in the gravelly mud.

  My destination was a small pond, no bigger than a backyard swimming pool. The surface was blanketed with leaves, dragonflies, and interconnecting swaths of green muck. I plodded along the bank, my sneakers sinking ever so slightly into the mud. Then, through a parting in the algae, I beheld a wondrous world of darting tadpoles and surging tree frogs. I plunged my net, a white mesh at the end of a three-foot wooden pole, into the water and dragged it along the viscous bottom. When I pulled it out, a small yellow frog was caught in the netting. I dropped it (along with a few leaves) into a garbage bag. With a few more sweeps, I collected more frogs, about six in all. I poked tiny holes in the plastic bag with the tip of a pencil and tied off the top. Then, after stuffing the bag into my backpack, I rode home.

  I dropped the bike at the side of the house and unlatched the wooden door leading to the backyard. Weeds peeked out of cracks in the cement path. Beside the covered patio was a small lemon tree. The fact that it was there always made me feel as if my backyard were a better, freer place than it really was. By then, darkness was approaching, replacing the jaundiced sky. From the kitchen, my mother called out to me to come in for dinner. I left the bag with the frogs on the patio. Inside, my mother asked me if I was going to feed the animals. I told her there was no point because they were going to be sacrificed anyway.

  Animal circulation, I’d learned from Mr. Crandall, evolved over millions of years. Mollusks and worms have a low-pressure, open circulation to ferry nutrients and waste. Larger animals developed tube-shaped vessels and pumps of growing complexity to circulate blood at higher pressure, thus enabling oxygen and nutrient delivery over longer distances. Fish hearts have two chambers; frog hearts have three. Human hearts are more intricate, with four chambers: two atria (the collecting compartments) and two ventricles (the pumps). Frogs require less oxygen than humans because they do not try to maintain a constant internal temperature. Unlike the humans who dissect them, frogs are cold-blooded.

  The next day, a Saturday, I took the garbage bag, my electrical apparatus, a scalpel, and a dissection tray and sat down on a plastic stool under our rusting swing set. In 1856, 127 years earlier, the anatomists Rudolf von Kölliker and Heinrich Müller measured the electric current of a frog’s heartbeat by passing the current down electrodes connected to a magnet, which produced a force that deflected a needle. With some modern technology, this was essentially the experiment I was going to try to replicate. I hooked up the electrodes to the voltage source to test the circuit, getting a clean 60-hertz signal on the oscilloscope. Because the electrode tips were fat and blunt, I wasn’t sure they’d make proper contact if the frog’s heart was too small, but that weekend was the best time for me to get the experiment done, so I decided to proceed anyway.

  I retrieved a frog from the depths of the bag. Grasping it firmly with my hand, I gently applied the scalpel to the beige skin on its back. It kicked its legs wildly, struggling to get free. When I inadvertently relaxed my grip, it got away, hopping around in the dry grass until I scooped it up. Squeezing its hip and hind legs securely until it stopped resisting, I tried again. By this point my own heart was popping against my breastbone, trying to break free. I pushed the tip of the scalpel a few millimeters through the soft foramen magnum and into the base of the skull. The frog struggled, so I pushed harder, feeling the cartilaginous carapace reluctantly give way. I must have been holding my breath—or perhaps hyperventilating—because tiny grains of black began to mottle my vision. I rattled the tip violently back and forth, nearly decapitating the animal. When I placed it in the dissection tray, it tried to drag itself to the edge. It gave one more weak jump before it went limp.

  I made a linear incision along the chest, which bled clear, viscous liquid. The heart was still beating, as far as I could tell—though it was hard to be sure, shrouded as it was by other thoracic structures. To clear the field, I tore out these organs with my fingers. By then my tears were flowing fast. The electrode tips were way too big, nearly the size of the heart itself. Nevertheless, in a panic, I directed them at the pea-sized organ, forgetting that they were still hooked up to the battery. When they made contact, an electrical spark crackled, singeing the chest. It smelled awful, even worse than the formaldehyde-soaked specimens in Mr. Crandall’s storage locker. By the time my mother came outside, I was bawling. I had tortured the poor creature, and moreover had nothing to show for it. My mother surveyed the scene carefully. Then, with her usual scolding sympathy, she said, “You should do a different experiment, son. Your heart is too small for this.”

  The next day, I steeled myself to try again, but when I went to retrieve another frog, the bag was empty; the frogs had disappeared. I still don’t know how they escaped (and neither did my mother). With no original data, I filled my paper with figures from textbooks. I got a B. Disappointed, I asked Mr. Crandall why. He said it was because I had learned nothing new.

  * * *

  If the heart bestows life and death, it also instigates metaphor: it is a vessel that fills with meaning. The fact that my mother associated my lack of courage with a small heart is no surprise; the heart has always been linked to bravery. During the Renaissance, the heart on a coat of arms was a symbol of faithfulness and courage. Even the word “courage” derives from the Latin cor, which means “heart.” A person with a small heart is easily frightened. Discouragement or fear is expressed as a loss of heart.

  This metaphor exists across cultures. After my grandfather died, my father, only fourteen, enrolled at Kanpur Agricultural College, the first in his family to pursue higher education. Every morning he would walk six kilometers to the academy because the family could not afford a bicycle. On the way home, lugging his bag of borrowed books, he would meet my grandmother at an appointed spot on the dusty road. When he would complain of feeling tired or overwhelmed, she would admonish her grieving boy to show strength. “Dil himmauth kar,” she’d say. Take heart.

  Shakespeare explored this motif in his traged
ies. In Antony and Cleopatra, Dercetas describes the warrior Antony’s suicide by the hand that “with the courage which the heart did lend it, splitted the heart.” Antony was distraught over what he believed to be Cleopatra’s treachery, and in describing Antony’s heartbreak, Shakespeare refers to another conception of the heart: as the locus of romantic love. “I made these wars for Egypt and the Queen,” Antony declares, “whose heart I thought I had, for she had mine.” As the critic Joan Lord Hall writes, Antony is conflicted over two very different conceptions of the metaphorical heart. In the end, his craving for battlefield glory overwhelms his desire for passionate fulfillment and leads to his self-destruction.

  The richness and breadth of human emotions are perhaps what distinguish us most from other animals, and throughout history and across many cultures, the heart has been thought of as the place where those emotions reside. The word “emotion” derives from the French verb émouvoir, meaning “to stir up,” and perhaps it is only logical that emotions would be linked to an organ characterized by its agitated movement. The idea that the heart is the locus of emotions has a history spanning from the ancient world. But this symbolism has endured.

  If we ask people which image they most associate with love, there is no doubt that the valentine heart would top the list. The ♥ shape, called a cardioid, is common in nature. It appears in the leaves, flowers, and seeds of many plants, including silphium, which was used for birth control in the early Middle Ages and may be the reason why the heart became associated with sex and romantic love (though the heart’s resemblance to the vulva probably also has something to do with it). Whatever the reason, hearts began to appear in paintings of lovers in the thirteenth century. (These depictions at first were restricted to aristocrats and members of the court—hence the term “courtship.”) Over time the pictures came to be colored red, the color of blood, a symbol of passion. Later, heart-shaped ivy, reputed for its longevity and grown on tombstones, became an emblem of eternal love. In the Roman Catholic Church, the ♥ shape became known as the Sacred Heart of Jesus; adorned with thorns and emitting ethereal light, it was an insignia of monastic love. Devotion to the Sacred Heart reached peak intensity in Europe in the Middle Ages. In the early fourteenth century, for instance, Heinrich Seuse, a Dominican monk, in a fit of pious fervor (and gruesome self-mutilation), took a stylus to his own chest to engrave the name of Jesus onto his heart. “Almighty God,” Seuse wrote, “give me strength this day to carry out my desire, for thou must be chiseled into the core of my heart.” The bliss of having a visible pledge of oneness with his true love, he added, made the very pain seem like a “sweet delight.” When his wounds healed in the spongy tissue, the sacred name was written in letters “the width of a cornstalk and the length of the joint of [a] little finger.” This association between the heart and different types of love has withstood modernity. When Barney Clark, a retired dentist with end-stage heart failure, received the first permanent artificial heart in Salt Lake City, Utah, on December 1, 1982, his wife of thirty-nine years asked the doctors, “Will he still be able to love me?”

  Today we know that emotions do not reside in the heart per se, but we nevertheless continue to subscribe to the heart’s symbolic connotations. Heart metaphors abound in everyday life and language. To “take heart” is to have courage. To “speak from the heart” conveys sincerity. We say we “learned by heart” what we have understood thoroughly or committed to memory. To “take something to heart” reflects worry or sadness. If your “heart goes out to someone,” you sympathize with his or her problems. Reconciliation or repentance requires a “change of heart.”

  Like the biological heart, the metaphorical heart has both size and shape. A bighearted person is generous; a small-hearted person is selfish (though when my mother said I had a small heart, I believe she meant I had a surfeit of compassion). The metaphorical heart is also a material entity. It can be made of gold, stone, even liquid (for example, being poured when we confess something). The metaphorical heart also possesses temperature—warm, cold, hot—as well as a characteristic geography. The center of a place is its heart. Your “heart of heart,” as Hamlet tells Horatio, is the place of your most sacred feelings. To “get to the heart” of something is to find out what is truly important, and just as the statue or monument at the heart of a city often has something to do with love, bravery, or courage, so too it is with the human heart.

  * * *

  Over the years, I have learned that the proper care of my patients depends on trying to understand (or at least recognize) their emotional states, stresses, worries, and fears. There is no other way to practice heart medicine. For even if the heart is not the seat of the emotions, it is highly responsive to them. In this sense, a record of our emotional life is written on our hearts. Fear and grief, for example, can cause profound myocardial injury. The nerves that control unconscious processes, such as the heartbeat, can sense distress and trigger a maladaptive fight-or-flight response that signals blood vessels to constrict, the heart to gallop, and blood pressure to rise, resulting in damage.

  In other words, it is increasingly clear that the biological heart is extraordinarily sensitive to our emotional system—to the metaphorical heart, if you will.

  In the early part of the twentieth century, Karl Pearson, a biostatistician studying cemetery headstones, noticed that husbands and wives tend to die within a year of each other. This finding supports what we now know to be true: heartbreak can cause heart attacks; loveless marriages can lead to chronic and acute heart disease. A 2004 study of nearly thirty thousand patients in fifty-two countries found that psychosocial factors, including depression and stress, were as strong risk factors for heart attacks as high blood pressure and nearly as important as diabetes. The heart might be a pump, but it is certainly not a simple one, and it is most definitely an emotional one.

  Takotsubo cardiomyopathy (from International Journal of Cardiology 209 [2016]: 196–205)

  There is a heart disorder first recognized about two decades ago called takotsubo cardiomyopathy, or the broken-heart syndrome, in which the heart acutely weakens in response to extreme stress or grief, such as after a romantic breakup or the death of a spouse. Patients (almost always women, for unclear reasons) develop symptoms that mimic those of a heart attack. They may develop chest pain and shortness of breath, even heart failure. On an echocardiogram, the heart muscle appears stunned, frequently ballooning into the shape of a takotsubo, a Japanese octopus-trapping pot with a wide bottom and a narrow neck.

  Though we don’t know exactly why this happens, the abnormal shape seems to reflect the distribution of adrenaline receptors in the normal heart. High adrenaline damages heart cells. Areas with higher receptor density (such as the apex, or bottom, of the heart) are more affected and therefore suffer the most damage. Though takotsubo cardiomyopathy often resolves within a few weeks, in the acute period it can cause heart failure, life-threatening arrhythmias, even death. The first studies of this disorder were in the early 1980s on victims of emotional or physical trauma (robbery, attempted murder) who seemed to die not from their injuries but from cardiac causes. Autopsies showed telltale signs of heart injury and cell death.

  Takotsubo cardiomyopathy is the archetype of a disease that is controlled by interactions between the emotions and the physical body. In no other condition do the biological and metaphorical hearts intersect so closely. The disorder can even occur when patients are not conscious of their grief. The husband of an elderly patient of mine had died. She was sad, of course, but accepting, maybe even a bit relieved: it had been a long illness; he had had dementia. But a week after the funeral, she looked at his picture and became tearful, and then she got chest pain, and with it came shortness of breath, distended neck veins, sweaty brow, a noticeable panting while she was quietly sitting in a chair: signs of congestive heart failure. On an ultrasound, her heart had weakened to less than half its normal function. But nothing on other tests was amiss—no sign of clogged arteries anywhe
re. Two weeks later, her emotional state had returned to normal and so, an ultrasound confirmed, had her heart.

  Takotsubo cardiomyopathy has been reported in many stressful situations, including public speaking, gambling losses, domestic disputes, even a surprise birthday party. “Outbreaks” of it have even been associated with widespread social upheaval, such as after a natural disaster. For example, on October 23, 2004, a major earthquake registering 6.8 on the Richter scale devastated Niigata Prefecture on Honshu, the largest island in Japan. Thirty-nine people were killed, and more than three thousand were injured. Landslides forced the closure of two national highways, disrupting telephone service and power and water supplies. On the heels of this catastrophe, researchers found that there was a twenty-four-fold increase in the number of takotsubo cardiomyopathy cases in the Niigata district one month after the earthquake, compared with a similar period the year before. The residences of those affected were closely correlated with the intensity of the tremor. In almost every case, patients lived near the epicenter.

  Using a nationwide database, scientists at the University of Arkansas identified almost 22,000 patients diagnosed with takotsubo cardiomyopathy in the United States in 2011. The highest rate of cases, nearly triple the national average, was in Vermont, where a tropical storm wreaked more damage that year than in nearly a century. The second-highest rate was in Missouri, where a massive tornado ripped through the town of Joplin, killing at least 158 people. Though these geographic areas were not the only ones hit by natural disasters that year, the scientists noted that their populations were perhaps less prepared because of a lack of experience with disasters and thus more vulnerable to the ensuing distress.

  By now, these findings should not surprise. Heart problems, including sudden cardiac death, have long been reported in individuals experiencing intense emotional disturbance—turmoil in their metaphorical hearts. The most unusual disturbances may have especially dramatic effects. In his book The Lost Art of Healing, the cardiologist Bernard Lown describes a case from an Indian medical journal in which a prisoner is condemned to death by hanging. A physician persuades the prisoner to allow authorities to bleed him rather than hang him because death by exsanguination is relatively painless. The man is strapped to a cot and blindfolded. Then his arms and legs are scratched, leading him to believe that he is bleeding. Lown writes: