http://well.blogs.nytimes.com/2012/08/10/think-like-a-doctor-a-peculiar-heartbeat-solved/
Think Like a Doctor: A Peculiar Heartbeat
By LISA SANDERS, M.D. The Challenge: Can you solve a medical mystery involving a 31-year-old woman with heart palpitations that leave her dizzy and short of breath?
We will provide you with the same details and test results the doctors had, but it’s up to you to figure out what additional information you need to unravel the mystery. As usual, I’ll be checking in regularly to answer your questions. The first person to figure out the diagnosis will get a copy of my book “Every Patient Tells a Story” and that warm smug feeling we all get when we solve the case — if not before Sherlock Holmes, at least before Dr. Watson.
The Presenting Problem:
A young woman feels dizzy and short of breath while vacationing with her family at the beach, and feels that her heart is beating irregularly.
The Patient’s Story:
It was the third day in a row of temperatures nearing 100, and the air felt heavy with its own sweat. The young woman had spent most of the morning submerged up to her shoulders in the cool waters of the Long Island Sound. But even here she felt awful. She was weak and tired. Her heart seemed to be flipping around in her chest. It wasn’t painful, but it was strange. And a little scary.The Emergency Room Doctor’s Exam:
When she finally headed toward the square of beach where her cousins lay stretched out on oversize towels, basking in the sun, she thought the heat of the day was going to kill her right then and there. When she was halfway up the beach, a wave of dizziness hit her and she had to stop. When it eased up, she made her way up to the family encampment to tell her cousins that it was time to go home. Her heart continued to flip around in her chest like a fish on a line as she trudged to the car.
She managed to drive to their grandmother’s house, where they were all staying. By then she was feeling even worse. Just getting out of the car seemed almost more than she could manage, and by the time she got into the air-conditioned kitchen, her legs were weak, her chest was tight and she felt as if she couldn’t get enough oxygen no matter how fast she breathed.
Until that moment she had been willing to write all of this off to her history of Graves disease, an autoimmune disorder in which the immune system mistakenly makes the thyroid overproduce its hormone. Graves leaves the body in a chronically revved-up state. She’d had the disease for almost a decade, but a few months ago she’d lost her job and, with it, her health insurance. So for the last several months she hadn’t been able to afford the medicine she needed to keep the disease in check.
The high levels of circulating thyroid hormone made her feel antsy. When her thyroid was out of control, she never wanted to eat and had trouble sleeping. She always felt hot, but that summer, the heat seemed unbearable. She was like a car with a broken carburetor, her engine always running a little high. Her heart was always racing. At times her heart rate was in the 90s (normal is 60 to 80 beats a minute), but usually it was over 100.
Sometimes she felt good when her thyroid was out of control, like she had all the energy in the world; sometimes she felt bad, all jittery and nervous. But she’d never felt like this.
On an impulse she grabbed her wrist and tried to take her own pulse. She found her inner rhythm just below her thumb joint. At first she wasn’t sure she was feeling the right place. The throbbing seemed much slower than usual, and it was also irregular. Like a phone call on a bad cell connection, every other beat or so was dropped. That scared her. She made her excuses to her grandmother, then drove herself to the closest emergency room she could find, at Waterbury Hospital, in Waterbury, Conn.
In the E.R., the patient wasn’t quite sure what to say when the nurse asked her why she was there. She knew it would sound strange, but she just blurted it out: Her heart was beating too slowly. The nurse looked at her oddly. Her pulse seemed normal enough, but the nurse took her into a room promptly, and after hooking her up to the heart monitor, the nurse hurried to get help. The patient’s heart was beating only 30 to 40 times a minute.
You can read the emergency department triage note below.
The E.R. doctor came right over. He asked a few questions and quickly examined her. Her exam was normal — except for her somewhat slow, very irregular heartbeat. Her chest X-ray was unremarkable. Her EKG, however, was not. It showed abnormal beats with an irregular rhythm. You can view the patient’s EKG below.
The emergency room doctor wasn’t sure what she had, but he didn’t have to be. What he did know was that she should be admitted to the hospital. You can read the E.R. doctor’s summary below.
Another Doctor Enters the Picture:
Dr. Sarita Soares was a resident who had just started her second year of training. When the call from the E.R. came, she hurried down to see the young woman with the peculiar heart rhythm. The patient was sitting up when the doctor entered the room. She looked ill, flushed and sweaty, as if she might have a fever. She didn’t. And her heart rate was surprisingly slow. Dr. Soares expected it to be racing, given her overheated appearance. Instead, on the monitor it ranged from the low 50s to the high 70s. It was strikingly irregular, though.
After the patient repeated her story, Dr. Soares asked a few more questions, trying to put it all together. No, the patient told her, she’d had no fever or chills. No joint pain. No pain with urination. No blood in her stools. She had a cough — she was a smoker; she’d smoked about a pack a day for 16 years — but the cough was no different from the usual. It didn’t get worse when she lay down. She didn’t feel nauseated, and didn’t have diarrhea or constipation. She had lost her job as a teacher in a group home eight months earlier in a round of layoffs at a hospital a couple of towns over.
She rarely drank. She didn’t use drugs. She had no medical problems other than the Graves disease and the occasional migraine headache, for which she took the occasional Fioricet.
She was drinking green tea to help her lose weight. She used to drink it several times a day but lately had cut down to a couple of glasses a week. She’d been in the hospital only once, when she delivered her son, and had never had surgery. In her family there was some diabetes. One grandmother had had breast cancer, but there was not a history of heart disease, and no one had died suddenly at a young age.
On exam, the doctor found some subtle traces of the patient’s history of Graves disease: Her eyes were a little prominent, her thyroid slightly enlarged, though not tender. The doctor placed her stethoscope over the middle of the thyroid gland. There were no extra sounds (known as bruits). The patient’s abdomen was soft and not tender, and she had no swelling in her legs or feet.
The E.R. doctor had gotten some blood tests, which, while helpful, did not provide a diagnosis. You can see the lab test results below.
Dr. Soares thought she might know what was causing the young woman’s symptoms, but first she needed to ask the patient a few more questions and examine her once more. Later she ordered some tests to confirm the diagnosis.Solving the Mystery:
Now, dear readers, I am turning the case over to you. What questions did the doctor ask, what did she see on exam and what additional tests did she order? What is this patient’s diagnosis?
I’ll post the answer tomorrow
Think Like a Doctor: A Peculiar Heartbeat Solved!
By LISA SANDERS, M.DThink Like a Doctor
Solve a medical mystery with Dr. Lisa Sanders.
The correct answer is…
Lyme carditisThe additional information the doctor sought included:
A question for the patient: Have you been in the woods lately? (She had.)More than 200 readers weighed in. The first reader to provide the correct diagnosis and most complete answer was Dr. Steven Anisman, a cardiologist in Vermont. He said that two nurse practitioners in his office had taught him to think of this entity.
A new finding during a re-examination: The doctor found a fading round, red rash on the patient’s wrist.
An additional lab test: The doctor ordered a Lyme Western blot and ELISA. The tests were hugely positive, but the diagnosis was made and the treatment started before the test results confirmed the diagnosis.
“We have two extremely talented nurse practitioners who help us with inpatient care, and every time we see heart block, they’re immediately thinking Lyme and ordering Lyme titers — often before I even get to see the patient,” he said. As a result, Dr. Anisman reports, their practice has diagnosed quite a few cases of Lyme carditis.
The Diagnosis:
Lyme disease is an infection caused by the bacterium known as Borrelia burgdorferi that can affect multiple body systems. Named after the town in Connecticut where it was first identified in 1975, Lyme is common throughout the Northeast, though cases have been reported as far south as the southern tip of Florida and Texas and as far west as Alaska. The disease is transmitted by one of the black-legged ticks — Ixodes scapularis in the Northeast, and Ixodes pacificus on the West Coast.How the Diagnosis Was Made:
The illness usually presents with a round, red, expanding rash (known as erythema migrans) and usually a fever, headache and joint and muscle pain. Cardiac involvement is common. Up to 10 percent of Lyme patients will have some cardiac involvement within the first few weeks of the infection, though most will report only palpitations. It is estimated that less than half of those with cardiac involvement will develop more significant symptoms, including a slowed heart rate.
Patients with Lyme carditis are treated to prevent later complications of Lyme disease and to shorten the duration of the cardiac effects. Because some of these manifestations can be life-threatening, patients who have symptoms of a slowed or irregular heart rate caused by Lyme, like this patient, should be hospitalized in a monitored bed and treated with intravenous antibiotics.
After Dr. Sarita Soares examined the patient, she excused herself and went out into the chaos of the emergency room to think. A patient with a history of hyperthyroidism who develops a slow heart rate might have de Quervain’s thyroiditis, a disease in which inflammation of the thyroid first causes symptoms related to too much thyroid hormone, but ultimately leads to the destruction of the thyroid gland. But this patient’s EKG didn’t support that diagnosis.
The patient’s EKG, which can be viewed below, shows that her heart was trying to beat faster. The little humps (circled) represent the heart’s natural rhythm generator and showed that part of the heart was working — indeed, it was working overtime. Thanks to her overactive thyroid, her heart was trying to go at a rate of about 140 beats a minute. But for some reason, Dr. Soares noted, the rest of the heart was able to respond to only a few of those attempted beats. What was interrupting it?
Possible Diagnoses:
Dr. Soares considered several possible diagnoses.Talking to the Patient:
Uncontrolled thyroid disease: Thyroid disease has been shown to cause this kind of cardiac abnormality. But it is a very rare complication of this disease and could be diagnosed only if nothing more likely was found.
Congenital heart block: Some babies are born with this kind of abnormal rhythm, but those infants are generally identified early in life.
Fibrous degeneration: The elderly can develop this kind of partly blocked heart rate, but that was unlikely in this young woman.
Heart block caused by coronary artery disease: Younger people can have this kind of blocked rhythm if a heart attack has injured the parts of the heart that carry the message to beat. In the distant past, the patient had used cocaine, a drug that causes the heart to age prematurely, so a heart attack was possible, but there was no other evidence that she had had a heart attack.
Medication-related heart block: Certain classes of drugs, like beta blockers, can do this, but this patient wasn’t taking any medicines.
Sarcoidosis: A disease that can hijack small pieces of tissue anywhere in the body and turn them into tiny nonfunctioning colonies of inflammatory cells, sarcoidosis is known to cause this kind of interrupted heartbeat. But even though this patient had some of the symptoms of sarcoidosis — fever, shortness of breath, cough and body aches are seen in nearly half of those who are found to have this somewhat mysterious disease — most will have abnormalities in a chest X-ray. Hers was completely normal.
Lyme disease: This was by far the most likely diagnosis. Lyme is common in the Northeast, and this kind of irregular heart rate was a known complication of untreated Lyme disease.
Dr. Soares returned to the patient’s room. Had she been out camping this summer? Sure, several times, the patient answered. Ever have any tick bites? Certainly. The patient said that she was always very conscientious about checking herself and her son for ticks. She’d pulled at least one off her body earlier this summer. Any rash? Not that she’d noticed.Treating the Patient:
Still, intrigued by the report of camping and known tick exposure, Dr. Soares examined the patient’s skin once more. There, on her arm near the wrist, was a fading red weal that she hadn’t seen earlier. It wasn’t the bull’s-eye rash classically described in Lyme, but Dr. Soares knew that most Lyme rashes are solid red rashes that expand over the course of several days, then disappear. And one in five patients with documented Lyme infections say they never saw a rash. Seeing that remnant rash clinched it for Dr. Soares. She told the patient her suspicions and ordered the confirming test to look for Lyme antibodies.
Dr. Soares started the patient on the recommended intravenous antibiotic. She would have to be watched in the monitored cardiac unit. And just in case the interruption of the heartbeats got any worse, she asked that pacer pads be put on the patient’s chest and back. If her heart got too slow, or stopped beating altogether, these pads could be turned on to force her heart to beat until a temporary pacemaker could be inserted. Because most of these patients will end up with a perfectly functioning heart once the Lyme has resolved, a permanent pacemaker is rarely needed.
The patient got a lot worse before she got better. The day after she was admitted, her heart rate slowed even more and she developed chest pain. She was immediately taken to the cath lab and given a temporary pacemaker. She was discharged after a few days, but returned a few days later with complications related to her antibiotic treatment. The patient eventually made a full recovery and has returned to full-time employment.
In medicine, we like to live by a rule first articulated by William of Ockham, a 14th-century Franciscan friar, that the simplest explanation is often the best. In medicine that usually means that most of the time, a symptom can be explained by a single diagnosis. Not so in this case. Indeed, it was in talking about this case that I came across what is known as Hickam’s dictum, a saying attributed to Dr. John Hickam, a 20th-century physician and teacher: “Patients can have as many diseases as they damn well please.”
