by DANIEL MUÑOZ
Another lesson I will take with me is the experience of latitude Dr. Martin gave me in managing the team—teaching, directing residents and nurses, laying out patient assessments, treatment plans, family communication. On rounds, at the end of each resident presentation, he’d invite me to lead: “Dr. Muñoz, what would you like to do here?” He was always supportive. If he did add something substantive, he’d low-key it—“And you might consider this…”—never taking credit. It was as if I were the attending, except I had a great attending to back me up. To turn the cliché around, I was performing with a net, a very good net.
This is also the first rotation that has given me a hint of the kind of work concentration I might want long-term. I like CICU challenges, the pace, the range of cases, the doctor-patient interaction, not just scans and readouts but doctor to patient, plus the element of teaching. Is this a glimpse of my future? We’ll see.
9
ROTATION: ELECTROPHYSIOLOGY
Circuit Board of the Heart
Another rotation finished, another one beginning. Last Friday, I was deep into the human side of cardiology—people with heart problems. Today, I’m back in the tech world, starting a rotation in EP—electrophysiology. It’s one of the sharpest contrasts in the fellowship, exceeded only by following consults (all about patients) with nuclear (all about pictures).
EP is the electrical study of the heart—in the vernacular, doctor as electrician. Commonly, you see an electrophysiologist for a pacemaker or defibrillator, but there’s considerably more to it. The heart is a muscle, but it’s also a highly choreographed electrical symphony, sending out impulses, which, when unsteady, cause short circuits. If there’s any heart rhythm disturbance—an irregular electrical signal that causes symptoms or potential danger—it often requires evaluation by an EP (electrophysiologist).
The parameters of an arrhythmia (abnormal rhythm) are expansive. There are two clinical subsets: “bradyarrhythmias” and “tachyarrhythmias.” Bradyarrhythmia, or bradycardia, is a heartbeat that is slow, sixty beats per minute or less, usually because of blocking of electrical impulses in the heart’s conduction system—simply put, wiring gone bad. There are trained Olympic athletes or some young, very fit people who have very slow resting heart rates. But in an ordinary person, if the rate falls below fifty beats per minute, symptoms such as fainting, shortness of breath, dizziness, light-headedness, chest discomfort, palpitations, and possibly death can occur.
Tachyarrhythmia, or tachycardia, is a heartbeat that is inappropriately fast, usually over one hundred beats per minute in an adult. If the heart rhythm is too rapid, it means the heart is in overdrive, working unsustainably hard. The heart may not have enough time to fill during ventricular relaxation (that is, the time span between contractions) and may pump an inadequate amount of blood to the brain or body. In certain vulnerable patients with little to no reserve, the immediate result can be serious: hypotension (low blood pressure) and a dangerous compromise in perfusion of vital organs (that is, delivery of sufficient flow to feed and support the organs, particularly the brain). The eventual result can be worse: organ failure or death. The job of the electrophysiologist is to identify and determine which of those heart rhythms is relevant and potentially dangerous, and what needs to be done.
Of all the rotations, this one feels the most foreign to me, the most daunting, because the people who typically do EP have intimidating intelligence. EP doctors tend to be electrical engineering majors, the type who never left their dorm rooms and whose senior theses had brilliant, incomprehensible titles. EPs have to be part physicist, part engineer, part biologist, part wizard, and able to integrate all of those roles. Plenty of cardiologists, if they’re honest, would likely admit to not comprehending the pure science behind electrophysiology. And at this point in my training, my exposure to the management of funky heart rhythms has been modest—the term funky itself a dead giveaway.
Fortunately, in electrophysiology, you have a lot of bosses. Instead of one principal supervising attending for the entire rotation, you have one per week, over four weeks. Part of my job as a first-year Fellow is to carry the EP consult pager, which means that I will be acting as the first line of contact. A typical call on the EP-1 pager could be an issue with a patient on another service (hospital department) who has a pacemaker and the team wants to know if it’s working properly. Simple, straightforward stuff. Except that I don’t know what is or isn’t working right, even though it is my job to try to decipher what the heart rhythm is, what I think needs to be done, and then hand the case off to a senior EP Fellow or the EP attending. It strikes me as perversely funny that when other doctors anywhere in the hospital have an EP-related question, they will call me—like giving a kid those plastic airplane captain’s wings and saying, “Go fly the plane.” I have nothing to qualify me except my official EP-1 pager.
My first EP consult call comes in at 10:00 a.m., when the resident on one of the medicine service teams leaves me a message: “We admitted this guy overnight with an abnormally slow heart rhythm. We’ve got to know, does he need a pacemaker?” This is exactly the kind of scenario I feared: A doctor is asking something I know precious little about, and it’s important. So I do what any prudent person would. I call the resident and say, “I’m happy to see the patient. Thanks for the consult. Get back to you shortly,” which is code for “I don’t know yet, but I will.” In other words, I stall.
I’m not worried about coming up with the right answer. There are places I can look: textbooks, journals, published guidelines. There are people I can ask: the EP experts. I’m concerned about sending a message of uncertainty to the doctors and perhaps to the patient or the patient’s family. And the best remedy for temporary ignorance is immediate diligence, to overdo the digging and learning, and get smart. Fortunately, my approach is possible because the pace of EP is generally measured and sane. My pager is not beeping like a broken car alarm. There’s plenty of time to ask questions, review the medical literature on the subject, and ultimately confer with the attending. Whereas general cardiac consults can be a much faster-paced rotation, with less time available to “look it up” when you don’t know the answer, the EP consult caseload tends to be slow and painstaking, like untangling marionette strings.
According to the chart, the patient is a seventy-seven-year-old man. My initial impression from the door is that he looks uncannily like Blue, the elderly frat member from the movie Old School. Our Mr. Blue lives in a little apartment complex, with neighbors and friends who look after him, but he’s fairly independent for his age. He was brought to the hospital by an EMS (emergency medical service) team after a neighbor found him dizzy and light-headed, unable to get out of bed or walk without almost falling over. The ER doctors immediately noted that his heart rate was thirty-five rather than in the normal sixty to eighty range—and Mr. Blue was no Olympic decathlete. At his age, a heart rate of thirty-five could be a life-threatening emergency, but what matters most is whether his heart is generating enough perfusion. The way to find out is not that complicated: “Sir, how are you feeling?” If his only answer is a moan, it’s a clear indication his brain is not being adequately perfused. If he can look you in the eye and says, “Doc, I’m fine. The ambulance brought me in because I haven’t been feeling so hot,” that’s a temporary confirmation that, for the moment, his brain is getting adequate blood flow.
Fortunately, the resident reports that Mr. Blue is able to converse. His blood pressure is okay, about 120 over 70. More important, he’s awake, alert, and seems oriented to the place, time, and situation. He’s passed the superficial tests. Nonetheless, somebody who’s seventy-seven with a heart rate of thirty-five doesn’t get sent home even if he is clinically perfusing. Instead, Mr. Blue is admitted to the cardiac step-down unit, which acts as an intermediary stage between a regular floor and the CICU. There, a first look at Mr. Blue’s EKG reveals some amount of heart block, or in EP terms, a degree of “conduction abnormality between the top chambers and
the bottom chambers.”
There are three basic degrees of heart block. First-degree block is less serious, and it will appear on the EKG as a prolonged interval between the first and second wave of the cardiac cycle: a delay that shouldn’t be there but may cause no immediate harm. A lot of people live asymptomatically with first-degree heart block. Second-degree heart block is the fuzzy area, a slightly more abnormal conduction pattern, between the relatively benign first and highly threatening third degrees. Third-degree, or complete, heart block, is when the top chambers and the bottom chambers aren’t coordinating activity. A patient in complete heart block will usually end up in the CICU, a wire placed through a catheter in the neck, floated down into the heart, to send electrical impulses to control the heart rate until a permanent pacemaker can be safely implanted.
It appears that Mr. Blue belongs to one of the subsets of second-degree heart block. Since he had a normal EKG at Hopkins a year prior, this situation is new and not good. And this is why the internal medicine team has asked for a consult on whether Mr. Blue needs a pacemaker.
Before I see Mr. Blue, I do a “chart biopsy,” which is an objective look inside the patient based on his or her total records—what’s happened, what’s been done, patient history, as well as the computer data on lab work and tests. I do it as a matter of practicality, a pattern I got into during cardiology consults. Walking in uninformed and asking the patient to tell me about himself would result in a conversation that could last for hours and never reveal what I need to know. The reality is that my task is not to hear a life journey, but instead to focus on developing an understanding of the patient’s heart rhythm. Based on Mr. Blue’s records, his bedside chart, and EKGs, I confirm that it looks to be a subset of second-degree heart block. At the nurses’ station, I scan the monitors on all the patients, and see that, thanks mostly to the passage of time, Mr. Blue’s heart rate is now forty, at least up from thirty-five.
When I walk in, Mr. Blue is lying in bed, a happy, smiling guy who has no idea why so many doctors are interested in him. I start off by introducing myself and asking some basic questions. “What brought you to the hospital?” He says, “Well, I felt a little funny at home, but now I feel better, and to tell you the truth, I don’t know why I’m here.” I ask, “Is anything bothering you?” He answers almost before I finish. “Yup! I’m hungry.” In the med school course informally titled Figuring Out Fast Whether the Patient Is Sick, if the chief complaint is hunger, it’s usually a good sign.
Then I start to ask more focused questions. Instead of asking “How long have you had health issues?” or “Has a doctor ever told you before that you have second-degree heart block?” I ask whether Mr. Blue has ever passed out before, and whether he often feels dizzy or light-headed. I ask direct questions about chest pain, shortness of breath, as symptom-based as possible. His answers are generally in the negative. He’s independent and functional, able to walk a few blocks every day without the assistance of a walker or a cane. He’s a content retired guy. But he does acknowledge that in the last two weeks, he’s had a couple of episodes where, during mild exertion, walking upstairs or getting out of bed, he felt light-headed. The most pronounced episode was yesterday, the day he came in.
Coupling this with his heart rhythm, I begin to wonder if Mr. Blue has deteriorated to second-degree heart block in just the last three weeks. If that were the case, he might need a pacemaker, which would assure his heart rate wouldn’t fall below a critical threshold (fifty beats per minute, for example), and he wouldn’t get symptomatic again. But it’s my first EP consult, in my first week of EP rotation, so I’m wary.
To qualify for a pacemaker, a patient must be diagnosed with a heart rhythm issue that is causing his or her symptoms and that has no underlying cause that we might be able to correct or reverse. In Mr. Blue’s case, he has a heart rhythm issue, which is causing his symptoms and which doesn’t seem to be something that we can quickly correct. I know that because I looked for other culprits—specifically, his medications. Mr. Blue is taking beta-blockers, which are prescribed to slow the heart rate and control the blood pressure. Too much beta-blocker and the heart can slow excessively. But this man has been on the same dosage of a beta-blocker for high blood pressure and coronary disease for years. The effects of a wrong dose would have declared themselves long ago. I check his liver and kidney function, because sometimes abnormal liver or kidney function can impact how the body metabolizes a beta-blocker, causing it to build up in the system and act like a higher dose than it is. But Mr. Blue’s liver and kidney function are both fine.
Nonetheless, while he’s in the hospital, we stop his beta-blocker in order to prevent his heart rate from slowing even further. I don’t expect that decision will correct his heart rhythm and obviate the need for a pacemaker, but this is my first consult and I err on the side of exploring options before electing to implant the device.
That evening, I meet with the week’s EP attending, Dr. Harry, and summarize the consult: “My sense is this is symptomatic bradycardia with second-degree heart block in the absence of a clearly reversible cause of that bradycardia. Because he is symptomatic, it’s an indication for a pacemaker.” He nods, so I go on: “In the interim, we’ve held back his beta-blocker because his heart rate’s thirty-five to forty.” Dr. Harry talks to the patient himself, then concludes, “I agree with your assessment, but let’s give him a day or two more off his beta-blocker and see what happens.”
The next day when I walk in, Mr. Blue’s heart rate is up to fifty, which is still low but considerably better. He remains hungry but otherwise has no complaints. The nurse takes him for a walk around the unit with a monitor on—no panting or wheezing, no pain—and he gets his heart rate up to the low seventies, which is very close to normal. When he lies down and is at rest, it dips back to the high forties to fifty, but still trending in the right direction. This puzzles me: Our only intervention so far has been stopping Mr. Blue’s beta-blocker. Why is he getting better when we withhold a medication he’s been taking for years? And if he is getting better, is he no longer a candidate for a pacemaker? It’s good news, but it doesn’t make physiologic sense, at least not to me.
My instincts say, do some medical detective work. It turns out the patient’s neighbor, a nursing student, helps with his medications. I get her on the phone and tell her that one of Mr. Blue’s medications may have caused a problem but we can’t figure out why. Before I can get another sentence out, she says, “I’m glad you called, because I’ve been concerned about his medicines for a long time. I try to lay them out, keep them in order, but now he’s less able to distinguish between the pills. I worry he gets confused, taking not enough of one, too much of another.” If her instincts are right, there’s a real possibility that Mr. Blue’s low heart rhythm was a response to accidentally taking too much of the beta-blocker.
The next day, after another twenty-four hours without the beta-blocker, Mr. Blue’s heart rate is in the low sixties. By the third day, it’s up to the midsixties, and he has a normal heart rhythm. The second-degree heart block is gone. Mr. Blue was discharged the next day, four days after being admitted—with a better pill-taking system in place, but without a pacemaker.
—
This is a humbling first consult because it makes me realize that my initial assessment was far too preliminary. The treatment plan quickly evolved from “Second-degree heart block, heart rate of thirty-five, serious symptoms, put in a pacemaker” to “No major problems, no light-headedness, no shortness of breath, just hungry, pretty soon we can send him home.” The “intervention” ended up being a very different variety than what I, or even the EP attending, Dr. Harry, originally thought we would need to do. It didn’t involve putting anything in; it involved finding out the patient was unintentionally taking too much beta-blocker. Sometimes waiting is good medicine, and Dr. Harry had the wisdom to weigh the possibilities before acting. And I’m glad that I followed my instincts, that I also trusted my doubts were t
rying to tell me something. Mr. Blue is a classic example that a lot of medical problems are due to a lack of information—information that may not be immediately available from the patient…but that doctors can obtain if they have the time, the resources, and the inclination to do a little digging.
The rest of the patients I see during the rotation are mostly the quick in and out, like patients with atrial fibrillation, who are in for electrical cardioversions. Atrial fibrillation, or atrial flutter, occurs when the top chambers of the heart are whipping away at too fast a rate. The bottom chambers that pump the blood try to ignore some of the noise from the top, but can’t and end up with a random, overly noisy beating of the heart that can cause symptoms such as shortness of breath, palpitations, and angina. Almost any exertion results in exhaustion, or the classic patient description of “I feel crappy.” Because the EP doctors specialize in mapping out the electrical network of the heart like a schematic diagram of house wiring, they can try to burn certain areas in an attempt to break the short circuits and get rid of the electrical impulse causing the abnormal rhythm. Cardioverting the patient, or directing an electrical current into the chest, can get the patient back into a normal or sinus rhythm, often improving or relieving symptoms and heart function.
My job is to meet the patients in a preprocedure room and talk to them, review their records, go through the consent procedure, where I describe what we’re going to do, cover the risks and benefits, and get their permission to proceed. Then I page the attending to room 11, the procedure room, to obtain the official go-ahead. We sedate the patients so they’re asleep but not “fully under,” while having them hooked up to monitors to track their vital signs—blood pressure and oxygenation. Once the patients are sedated, we put pads on their chest and administer timed delivery of electric shock, to reset the cardiac cycle. Again, with the go-ahead from the attending, I press a button that unleashes a two hundred–joule shock to the patient’s chest. For the next second, everyone holds their breath to see if it put the heart back in normal rhythm. Despite being sedated and asleep, patients will occasionally let out a bloodcurdling shriek or string of profanity after being whacked in the chest by all that electricity. Fortunately, the sedating medications ensure that patients do not remember this, and once the sedation wears off, most leave the same day.
