Answer: D. Admit the patient to the step-down unit and initiate intravenous ceftriaxone
This man is presenting with late cardiac complications of Borrelia Burgdorferi infection, or Lyme disease. The ECG reveals high-grade atrioventricular block. His prior ECGs have been normal. The historical features of frequent camping, a rash (erythema migrans), and arthritis should trigger concern for Lyme disease. The diagnosis should be confirmed with enzyme-linked immunosorbent assay (ELISA) serologic testing for B burgdorferi antibodies, followed by a Western blot for positive or equivocal results.1
Patients with cardiac manifestations of Lyme disease (also known as Lyme carditis) should be admitted to telemetry and started on intravenous (IV) antibiotics, preferably ceftriazone or high-dose penicillin G.1 IV antibiotics should be continued for at least 4 weeks.1 Choice C is incorrect because the acuity of this patient’s presentation warrants hospital admission and corticosteroids are not recommended.1 A transcutaneous pacemaker is typically not needed in this setting if the patient has an adequate escape rhythm, and permanent pacemakers are contraindicated (class III),2 because Lyme disease is a reversible cause of complete heart block, usually resolving after 1 week of antibiotic therapy.1
- Fish AE, Pride YB, Pinto DS. Lyme carditis. Infect Dis Clin North Am. 2008;22(2):275-288.
- Epstein AE, DiMarco JP, Ellenbogen KA, et al. ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: a report of the American College of Cardiology/American Heart Association task force on practice guidelines. J Am Coll Cardiol. 2008;51(21):e1-e62.