Heart: An American Medical Odyssey
Page 6
DR. REINER
An eclectic playlist streams softly in the background as I back through the doorway, warm water dripping from my arms. The staff, wearing masks, scrubs, and several pounds of protective lead, go about their jobs with an efficient, good-humored professionalism. The patient, covered neck to toe by a blue surgical drape, lies cruciform on a narrow gantry, eyes closed in a fentanyl-induced fugue, his right arm strapped to a board, palm up and perpendicular to the table, an oval opening in the drape exposing his wrist painted orange with antiseptic scrub. Two palm-sized patches on his chest are attached to the defibrillator perched on a rolling cart near the wall, its reassuring beeps quickly fading into familiar white noise. I dry my hands with a towel and slip into the sleeves of a sterile gown that unfolds with a quick downward flip. I pull on a pair of gloves, the latex issuing its characteristic thwack as I release each cuff. A nurse ties the back of my gown, and I step toward the patient preparing for a routine procedure that not long ago was impossible.
• • •
For millennia, the human heart remained mysterious and inviolable, the center of the physical body and the immortal soul, the sacred wellspring of character, intelligence, and valor.
In ancient Egypt, the heart was the only internal organ left in place during mummification, believed indispensable in Duat, the underworld, where it would be weighed against a feather, the symbol of Maat, goddess of truth and justice. Should the scales balance, the deceased would be deemed worthy of admission to the afterlife. If, however, the heart was heavy, Ammit, the devourer of the dead, a fearsome creature with the head of a crocodile, body of a lion, and hindquarter of a hippopotamus, would consume the heart, leaving the soul without rest.
Although the Greeks of the fourth century B.C. knew that the heart had four chambers and understood its anatomical relationship to the large blood vessels arising from it, knowledge they derived principally from the dissection of animals, luminaries like Aristotle and Hippocrates did not understand the organ’s role in the circulation of blood. Aristotle believed that the heart was the center of human consciousness, and in many of the languages that evolved over the millennia, the word heart represents more than just the cardiac structure. Mandarin uses the same character (xīn) for both “heart” and “mind.” The English word courage is derived from the Latin cor (heart), as are its Italian, French, and Portuguese counterparts, and the word core literally means heart.
At the beginning of the third century B.C., human dissection was permitted in Alexandria, and it was there that important advances were made in understanding the structure of the vascular system. The Greek physician Herophilus correctly considered the atria part of the heart (as opposed to part of the vessels leading into the heart) and was the first to describe the differences between the thick-walled arteries and the thin-walled veins, noting correctly that the vessel exiting the right ventricle was an artery, not a vein, and the vessels leading into the left atrium were veins, not arteries. Herophilus is also credited as being the first physician to count the pulse, though he incorrectly believed that the pulsations were caused by the contraction of the arteries.
Galen, a second-century Greek physician who lived in the Roman Empire and whose writings would dominate medicine for fifteen hundred years, believed that the heart was the source of the body’s heat and moved pneuma (air, vital spirits) around the body. Although Galen did not believe that the heart was a muscle, he clearly understood its unique attributes:
Its flesh is hard and not easily injured, being composed of fibres of many different kinds, and because of this, even if it would appear to be like muscles it is clearly different from them. . . . And in its hardness, tone, or tension and general strength and resistance to injury, the fibres of the heart much surpass all other fibres. For no organ functions so continuously, or moves with such force as the heart.
The classic view of circulation, which would perpetuate into the seventeenth century, can be summarized. The veins, it was thought, were the principal blood vessels and arose from the liver; the arteries contained only a small amount of blood mixed with pneuma; the heart provided the body’s heat and vital spirits; blood was propelled by inspiration; and the pulse was caused by contraction of the arteries.
Even Leonardo da Vinci, whose detailed dissections and subsequent drawings so elegantly depicted the anatomy of the heart, could not break with the Aristotelian and Galenic view of the purpose of the heart, though he came close to articulating its role in circulation when he wrote, “The heart is the seed which engenders the tree of the veins.”
William Harvey, an English physician born in Folkestone, Kent, on April 1, 1578, had a different idea, and in 1628 he published a ninety-page book, On the Motion of the Heart and Blood in Living Beings (De Motu Cordis). In the introduction to an 1889 English translation from the original Latin, Alexander Bowie succinctly summarizes Harvey’s theory:
That there is one blood stream, common to both arteries and veins; that the blood poured into the right auricle, passes into the right ventricle; that it is from there forced by the contraction of the ventricular walls along the pulmonary artery through the lungs and pulmonary veins to the left auricle; that it then passes into the left ventricle to be distributed through the aorta to every part of the animal body; and that the heart is the great propeller of this perpetual motion, as in a circle; this is the great truth of the motion of the heart and blood, commonly called the circulation, and must forever remain the glorious legacy of William Harvey.
Although Harvey describes for the first time the physiology of the circulatory system, he does not refute the heart’s incorporeal role:
The heart of animals is the foundation of their life, the sovereign of everything within them, the sun of their microcosm, that upon which all growth depends, from which all power proceeds.
Until the twentieth century, entry to the heart, be it accidental, intentional, or surgical, was believed to lead to certain death. In 1902, the surgeon Harry Sherman described the heart:
An organ . . . particularly vulnerable—in fact, so vulnerable that any interference, even for surgical purposes, might be followed by immediate fatal results.
• • •
In 1929, Werner Forssmann, a German physician, set out to challenge the dogma that declared the heart sacrosanct. Forssmann, twenty-five years old at the time, was interested in finding a safe route into the chambers of the heart. Although studies in cadavers demonstrated the technical feasibility of his idea, Forssmann’s hospital chief forbade him from performing the experiment on a patient. Undeterred, Forssmann decided to perform it on himself. In a now legendary and visionary display of both arrogance and bravery, a colleague placed a large-bore needle into the brachial vein of Forssmann’s right arm and then advanced a well-lubricated ureteral catheter a short distance. A week later, now without assistance, Forssmann anesthetized his own left arm, punctured a vein, and inserted the catheter its entire sixty centimeters length. In a 1929 paper describing his experiment, Forssmann wrote:
I checked the catheter position radiologically, after having climbed stairs from the OR to the radiology department. A nurse was holding a mirror in front of the X-ray screen for me to observe the catheter advance in position. The length of the catheter did not allow further advancement than into the right atrium. I paid particular attention to the possible effects on the cardiac conduction system, but could not detect any effect.
Forssmann’s maverick work proved that an intrusion into the heart need not be deadly and thus unlocked the door to the heart. For the next quarter-century, other physicians, including Dr. André Cournand and Dr. Dickinson Richards of Columbia University (who would share the Nobel Prize with Forssmann in 1956), refined Forssmann’s technique, conducting hemodynamic and dye studies within the cardiac chambers that exponentially expanded knowledge of the structure and physiology of the heart. Imaging of the coronary arteries, however, remained out-of-bounds as physicians believed that a direct injection of dye into a
coronary vessel would cause cardiac arrest.
Another paradigm shift occurred in 1958 when Dr. Mason Sones, a Cleveland Clinic cardiologist, made one of medicine’s great serendipitous discoveries after his catheter accidentally engaged the origin of a twenty-six-year-old patient’s right coronary artery and dye was mistakenly injected. A great commotion ensued in the procedure room, but the patient did not die, and Sones’s accident became the world’s first coronary angiogram. Finally there was a way to create a detailed road map of the arteries supplying the heart.
• • •
In the early years, cardiac catheterization was an audacious and cumbersome procedure requiring an overnight hospital stay. The X-ray dye was quite toxic, frequently causing nausea and vomiting and, occasionally, cardiac arrest. Patients were instructed to cough violently, a primitive but effective way of maintaining a minimal cardiac output should the heart rate suddenly drop. Manipulation of rigid catheters in diseased arteries was hazardous work, occasionally resulting in vessel injury, perforation, or closure. The mortality rate was a risky 1 percent when cardiac catheterization was originally introduced and dropped steadily thereafter, but the procedure continued to carry hazards. My uncle Henry died during a cardiac catheterization in 1980 while I was a junior in college. I remember my father calling to give me the sad news that his older brother was dead and then trying to describe the procedure that had killed him. I had never before heard of heart catheterization; I remember thinking how terrible it was that an ostensibly healthy man could die while undergoing it.
• • •
I stand on the right side of the patient facing a huge, flat panel screen suspended from ceiling-mounted rails by a thick metal post. Not your typical big-screen TV, the glossy $100,000 ultra-high-resolution monitor is capable of simultaneously displaying a dozen medical-grade inputs and is powered by a six-foot-tall rack of video servers in the next room. Interventional cardiologists are often gadget geeks who wouldn’t be caught dead with last year’s phone, and a cath lab is a multimillion-dollar cathedral to the latest technology.
With the patient asleep and the lights in the room dimmed, I reach up to focus a small surgical spotlight on the upturned right wrist. In most patients, blood is supplied to the hand through the ulnar and radial arteries, redundant vessels that meet in a vascular arch in the palm. Like the interstate highway system, all arteries eventually connect, and the radial artery, easy to identify and compress, lying just under the skin, makes an ideal entry point.
In the 1960s and 1970s, coronary arteriography required a surgical cut-down to expose the brachial artery, located in the crook of an elbow. In the late 1980s and 1990s, the preferred route of entry became the femoral artery, a large vessel in the groin accessible by needle, but often located deep under the skin and occasionally prone to severe or fatal bleeding. In the United States, use of the radial artery for access is relatively new, but European cardiologists have used this method for years, recognizing its superior safety and comfort compared with puncturing the leg. American doctors have been slow to adopt the technique because, until recently, very few were taught it during their years of training, there is a learning curve that requires several dozen cases before flattening out, and some physicians are reluctant to learn new tricks. I learned the procedure from my former fellow, and now colleague, Dr. Ramesh Mazhari, who quite patiently taught her former teacher.
Using a very fine needle, I inject a small amount of lidocaine under the skin on the thumb side, about two finger breadths above the horizontal wrist crease. After allowing the anesthetic to take effect, I pinch an IV catheter between my right thumb and forefinger and, with my other hand, get a fix on the location of the pulsating vessel lying a millimeter or two below. Very deliberately, as if demonstrating the procedure in slow motion, I pierce the skin aiming for the target under my left hand, and a few seconds later a crimson flash appears in the IV announcing the needle’s arrival in the slim radial artery. I step on a foot pedal to turn on the X-ray tube mounted in the large C-shaped arm encircling the patient and watch on the monitor as the curved tip of a thin wire slides through the radial artery sheath and up the arm toward the shoulder. A one-meter-long catheter is threaded onto the wire, and together they are navigated through the radial and brachial arteries of the arm to the axillary and subclavian arteries of the shoulder and finally down into the aorta to the level of the aortic valve, from where the coronary arteries arise.
Through my latex gloves, I can feel the familiar supple smoothness of the catheter. With a subtle clockwise torque I engage the origin of the coronary, the two-millimeter polyethylene catheter now swinging in synchrony with the moving muscle. I glance quickly at the patient and then at the EKG and blood pressure waveforms while I work the controls to position the digital detector above the patient’s head for the first set of images. A programmable power injector delivers six milliliters of iodinated X-ray contrast into the coronary artery; on the monitor, a gray-scale road map of the vessel plays back in a continuous loop, the angular borders of the vessel flexing in concert with the underlying myocardium. I repeat the imaging in multiple projections before switching catheters to assess the other coronaries. Finally, I pass a rounded catheter, shaped like a pig’s tail, across the aortic valve and inject dye into the heart, inside the left ventricle, creating a vivid image of the contracting heart. The images acquired during the cardiac catheterization are stored in an array of servers, immediately reviewable on workstations around the hospital, and over the Internet, on my iPad, smart phone, or computer anywhere in the world.
The patient occasionally stirs but will not remember the half-hour procedure, accomplished through a 2-millimeter puncture in his wrist.
• • •
Two weeks after the November 1978 election, and five months after his heart attack, Dick Cheney underwent a follow-up stress test at Natrona County Memorial Hospital in Casper. Now back at unrestricted activity, walking every day for exercise, weighing a slimmer 179 pounds, and no longer smoking, the newly elected congressman achieved a peak heart rate of 200 beats per minute without chest pain or EKG abnormalities.
Although he was demonstrating reassuring cardiac fitness at the outset of his congressional career, the stress test could not delineate the amount of Cheney’s underlying coronary disease or whether another heart attack was imminent. In a February 1979 letter to Dr. Freeman Cary, the attending physician of the US Capitol, Dr. Hiser had raised the possibility of coronary arteriography (that is, cardiac catheterization) to further define Cheney’s coronary anatomy:
Dick Cheney suffered an inferior myocardial infarction in 1978. He has had several treadmills performed since then and has done quite well on them. . . . He had been recommended to have coronary arteriography performed because of his young age and the brilliant career he should have before him. He has not made a final decision as to whether he would desire to have this done.
The day before Thanksgiving in 1979, almost a year and a half after his heart attack, Cheney finally underwent cardiac catheterization to define the extent of his coronary artery disease. Dr. Al Del Negro performed the procedure at Georgetown University Hospital in Washington, DC, employing a now archaic surgical cutdown to expose the brachial artery in the patient’s right arm. Using fluoroscopy, a series of catheters were passed to the heart through the incision in the arm, and a hand-powered syringe forcefully injected contrast into the congressman’s coronaries. The images were captured on 35 mm movie film, processed in a darkroom at the conclusion of the procedure, and reviewed later with the aid of a projector.
Mr. Cheney was found to have a 50 percent narrowing in the right coronary artery, the vessel supplying the underside of the heart (a moderate lesion) and a 75 percent blockage in the circumflex branch, which supplies the side of the heart, the likely culprit for the heart attack a year and a half earlier. Overall, the test demonstrated not enough disease to warrant coronary artery bypass graft surgery, but much more disease than one would want to see, o
r expect to find, in a thirty-eight-year-old man.
CHAPTER 4
Cura Personalis
No one cares how much you know, until they know how much you care.
—THEODORE ROOSEVELT
DR. REINER
It’s said that law school doesn’t teach students the law; it teaches them how to think like lawyers. Medical school, on the other hand, teaches plenty of science but very little of the art of being a doctor. Humanism, the notion that a physician should focus on the care of the patient rather than the treatment of the disease—what the Jesuits at Georgetown call cura personalis, or care for the whole person—is difficult to incorporate into medical training. How does a student learn to combine competence with compassion or optimism with realism? You learn from your patients and your peers, senior physicians, and those only a step or two ahead, mentors with attributes to be emulated and others with traits to avoid. It’s an education that continues for a lifetime, and it began for me at the end of medical school when I found myself in the belly of the beast.
• • •
I awoke one morning in my junior year of medical school covered in hives. The textbooks call it urticaria, “an allergic skin eruption characterized by multiple, circumscribed, smooth, raised, pinkish, itchy wheals, developing very suddenly, usually lasting a few days, and leaving no visible trace.” The lesions are the end result of the release into the skin of histamine, a chemical mediator of inflammation. The list of potential triggers of urticaria is long: foods, medications, insect bites, animal dander, viral infections, autoimmune diseases, pollen, heat, cold, emotional stress, and, very rarely, malignancy.