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The amount of blood that passes through an average adult heart in a week could fill a backyard swimming pool.
Heart cells grown in a petri dish start to contract spontaneously, seeking out other cells (through electrical connections called gap junctions) to synchronize in their rhythmic dance. In this sense, cardiac cells—and the organ they create—are social entities.
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.
What these deaths had in common was the victims’ absolute belief that there was an external force that could cause their demise and against which they were powerless to fight. This perceived lack of control, Cannon postulated, resulted in an unmitigated physiological response in which blood vessels constricted to such a degree that blood volume acutely dropped, blood pressure plummeted, the heart acutely weakened, and massive organ damage resulted from a lack of transported oxygen.
For all its outward symmetry, the human body is not symmetric. The left lung, for example, has only two lobes, unlike its tri-lobed counterpart on the other side. (The left lung’s middle lobe atrophies during fetal development because the heart gobbles up its space.)
In neuroscience, there is the concept of the reflex arc, in which a threatening stimulus can effect a response without passing through the conscious brain—for example, when you see the taillight flash red on the car speeding in front of you and your foot automatically moves to the brake pedal.
The first use of surgical hypothermia was presented by Wilfred Bigelow, a Canadian surgeon, at a conference in Denver in 1950. Bigelow anesthetized laboratory dogs, cooled them in an ice bath, opened their chests, clamped off their hearts to stop blood flow, and then de-clamped, stitched, warmed, and woke them up with no permanent brain damage.
Lillehei made it clear to the Gliddens that he had used cross-circulation only on dogs, but he told them that if a child of his needed open-heart surgery, he would not hesitate to use the technique. Desperate, the Gliddens gave the go-ahead. The consent form they signed in March 1954 was a single sentence: “I, the undersigned, hereby grant permission for an operation or any procedure the University staff deems necessary upon my son.”
The American Heart Association still does not list emotional stress among the key modifiable risk factors for heart disease—perhaps in part because serum cholesterol is so much easier to reduce than emotional and social disruption. We need a better way, one that recognizes the power and importance of emotions that the heart—the metaphorical heart—was believed to house for millennia.
The vulnerable period is crucial to understanding why normal hearts can self-electrocute. For example, when a healthy young athlete drops dead after getting a blow to the chest from a baseball or hockey puck, it is because the heart was hit during its vulnerable period. Scientists have confirmed the presence of the vulnerable period in mammals by slamming a baseball mounted at the end of an aluminum shaft into the chests of eight- to twelve-week-old anesthetized piglets at various times in the cardiac cycle. They found that when the impact occurs within a narrow window 10 milliseconds long and
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Like much of what Lillehei did as a surgeon, there was no precedent for the myocardial wire. There was no way of knowing up front that it would work, that it wouldn’t cause a host of complications—infection, bleeding, scarring—that putting a piece of metal inside the human body and leaving it there, tunneling a portion of it out through a break in the skin that could serve as a portal for germs, wasn’t totally ridiculous. It was impossible to know any of this without trying. But Lillehei, more than any doctor of the twentieth century, specialized in trying the outlandish.
As with so many great cardiac innovations of the past century, the inspiration for Greatbatch’s invention was a mistake. In the early 1950s, Greatbatch was working on a livestock farm near Ithaca, New York, testing instruments to monitor heart rate and brain waves in sheep and goats, when he learned about heart block from two surgeons doing a summer research sabbatical there. “When they described it, I knew I could fix it,” Greatbatch later wrote. A few years later in Buffalo, Greatbatch was working with the newly invented transistor when he accidentally installed a resistor into a circuit he
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The most recent devices produce continuous blood flow, so patients emerge from the operating room without a pulse. Continuous-flow devices are simpler than devices that send out pulses of blood, mimicking the native heart. They don’t require valves and have fewer moving parts, resulting in less wear and tear. They still pump blood, of course, but the flow is constant, not periodic. Incredibly, humans, we now know, can live for long periods without pulsatile blood flow. However, continuous-flow hearts produce their own complications. They chew up blood cells because of the shear forces
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The morgue was inside Brooks Brothers. I was standing at the corner of Church and Dey, right next to the rubble of the World Trade Center, when a policeman shouted that doctors were needed at the menswear emporium inside the building at One Liberty Plaza. Bodies were piling up there, he said, and another makeshift morgue on the other side of the rubble had just closed. I volunteered and set off down the debris-strewn street.
Someone asked whether a separate body bag was needed for each body part, but no one knew the answer.
A physician told me he happened to be standing outside the first tower when it collapsed. “I ran under a bridge,” he said. “There was huge debris falling all around me. Every step I took, I kept saying to myself, ‘I can’t believe I’m not dead yet; I can’t believe I’m not dead yet.’” Then he began hearing strange thuds. Those, a firefighter told him, were people jumping off buildings.
But all medical technology carries a different price. Artificial hearts cause blood clots and disabling strokes. Dialysis saves lives but often results in painful, even life-threatening, infections. For implantable defibrillators, designed to deliver peace of mind, one of the biggest downsides, paradoxically, is fear.
I don’t remember ever thinking that my mother’s dreams could be fatal, but in retrospect, after she got her coronary stent, we should have been more concerned.
After each stepwise decline, she’d insist, “If I can stay like this, it’ll be okay.” She was able to recalibrate her expectations as her condition deteriorated, leaving her spirit mostly intact. But it was painful to watch.
At the funeral of a friend’s mother two years before, a colleague had said to me, “You never really grow up until your parents die.” Now, finally, I understood what he meant. What he meant was, while your parents are alive, there is always someone who thinks of you as a child.
South Asians seem to have smaller coronary arteries than other ethnic groups, which may result in more turbulent blood flow and wall stress that can initiate atherosclerosis. South Asian blood may also contain smaller and denser cholesterol particles that are more prone to causing arterial hardening.
Cardiology in its current form might have reached the limits of what it can do to prolong life.
Yet a study of nearly 100,000 patients published in 2013 in The New England Journal of Medicine found that shorter “door-to-balloon” times—the period from a patient’s hospital presentation to inflation of a balloon to restore coronary blood flow—did not improve in-hospital survival. The median door-to-balloon time dropped to sixty-seven minutes, from eighty-three, in the period studied, but short-term death rates did not change.
believe that cardiovascular medicine in its current form, focusing on investigating minor iterations of commonly used drugs or add-on therapies or optimizing existing procedures, will increasingly produce only marginal advances in the years ahead. We will need to shift to a new paradigm, one focused on prevention—turning down the faucet rather than mopping up the floor—to continue to make the kind of progress to which patients and doctors have become accustomed.
