Medical Mystery: Bradycardia — The Answer
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《新英格兰医药杂志》
To the Editor: The medical mystery in the June 2 issue1 involved a 49-year-old man who reported fatigue, arthralgia, and headache, along with a two-day history of chest pain; an electrocardiogram (Figure 1) had been obtained. The patient was hospitalized. Myocardial infarction was ruled out. The findings on echocardiography were unremarkable. A serologic analysis for Lyme disease was positive, with confirmation by Western blotting. On further questioning, the patient noted that he had received a tick bite six weeks earlier and that it had been associated with a brief febrile illness without a rash.
Figure 1. Electrocardiogram from a Man with Fatigue, Arthralgia, Headache, and Chest Pain.
Intravenous administration of ceftriaxone (2 g daily) was begun. On day 4, the second-degree heart block resolved, but the first-degree heart block and ischemic changes persisted. A nuclear-isotope study with dipyridamole revealed an anterior lateral reversible defect, thought to be consistent with ischemia or myocarditis. The results of cardiac catheterization were normal. Two weeks after intravenous ceftriaxone therapy, the electrocardiogram was normal (Figure 2) and the patient was well. Heart block associated with Lyme disease typically responds to antimicrobial therapy and rarely requires placement of a permanent pacemaker.
Figure 2. Electrocardiogram after Treatment with Ceftriaxone for Lyme Disease.
Ralph Rosenberg, M.D.
University of Connecticut Health Center
Avon, CT 06001
References
Rosenberg R. A medical mystery -- bradycardia. N Engl J Med 2005;352:2337-2337.
Editor's note: We received 1575 responses to this medical mystery; 59 percent were from physicians in practice, 23 percent from physicians in training, 10 percent from medical students, and 8 percent from other readers. Forty-nine percent of the responses were from 79 countries outside the United States. Forty-three percent of the respondents correctly diagnosed Lyme disease, whereas 25 percent suggested a cardiac-conduction abnormality, and 16 percent suggested myocardial ischemia. Others provided explanations that included drug toxicity (e.g., due to atorvastatin), in 3 percent of the responses; endocrine dysfunction (e.g., hypothyroidism), in 3 percent; and other diagnoses (e.g., endocarditis, acute rheumatic fever, Chagas' disease, and sarcoidosis), in 10 percent. We received many insightful comments, including the following:
The high degree of atrioventricular nodal block in combination with constitutional symptoms, arthralgia, and headache all point toward a diagnosis of Lyme disease. That he presented in June to a health care facility in Connecticut clinches the diagnosis!
— Toby Maher, M.R.C.P.
Oh the beautiful springtime in Connecticut!
The flowers, the bees, the mice, the deer,
and the tick.
Don't rush to a pacemaker;
IV ceftriaxone will do the trick.
— Thomas J. Lester, M.D.
Figure 1. Electrocardiogram from a Man with Fatigue, Arthralgia, Headache, and Chest Pain.
Intravenous administration of ceftriaxone (2 g daily) was begun. On day 4, the second-degree heart block resolved, but the first-degree heart block and ischemic changes persisted. A nuclear-isotope study with dipyridamole revealed an anterior lateral reversible defect, thought to be consistent with ischemia or myocarditis. The results of cardiac catheterization were normal. Two weeks after intravenous ceftriaxone therapy, the electrocardiogram was normal (Figure 2) and the patient was well. Heart block associated with Lyme disease typically responds to antimicrobial therapy and rarely requires placement of a permanent pacemaker.
Figure 2. Electrocardiogram after Treatment with Ceftriaxone for Lyme Disease.
Ralph Rosenberg, M.D.
University of Connecticut Health Center
Avon, CT 06001
References
Rosenberg R. A medical mystery -- bradycardia. N Engl J Med 2005;352:2337-2337.
Editor's note: We received 1575 responses to this medical mystery; 59 percent were from physicians in practice, 23 percent from physicians in training, 10 percent from medical students, and 8 percent from other readers. Forty-nine percent of the responses were from 79 countries outside the United States. Forty-three percent of the respondents correctly diagnosed Lyme disease, whereas 25 percent suggested a cardiac-conduction abnormality, and 16 percent suggested myocardial ischemia. Others provided explanations that included drug toxicity (e.g., due to atorvastatin), in 3 percent of the responses; endocrine dysfunction (e.g., hypothyroidism), in 3 percent; and other diagnoses (e.g., endocarditis, acute rheumatic fever, Chagas' disease, and sarcoidosis), in 10 percent. We received many insightful comments, including the following:
The high degree of atrioventricular nodal block in combination with constitutional symptoms, arthralgia, and headache all point toward a diagnosis of Lyme disease. That he presented in June to a health care facility in Connecticut clinches the diagnosis!
— Toby Maher, M.R.C.P.
Oh the beautiful springtime in Connecticut!
The flowers, the bees, the mice, the deer,
and the tick.
Don't rush to a pacemaker;
IV ceftriaxone will do the trick.
— Thomas J. Lester, M.D.