Abstract
Lyme borreliosis is an infectious disease that is increasing in frequency and can cause various forms of carditis in its disseminated phase. In otherwise healthy patients presenting with new-onset atrio-ventricular dissociation, Lyme carditis must be on the differential; however, due to its rarity in non-endemic regions, the clinician must remain vigilant and keep it on the differential. The objective of this clinical case report is to call attention to the importance of rapid diagnosis of Lyme carditis in regions where the disease is not common. The patient presented in this report is a 27-year-old, previously healthy male complaining of fatigue and presyncope over the past 48 hours who presented to a community ED in western Washington State. He had been traveling the country rock climbing and recalled a febrile illness and rash in the preceding three months. He was found to be in third-degree atrio-ventricular block on admission to the ED and was promptly diagnosed with Lyme carditis. He was hospitalized on telemetry monitoring and was treated with transvenous cardiac pacing and IV ceftriaxone. His atrio-ventricular block gradually resolved and he was discharged without need for permanent pacemaker placement. He was able to return to his active lifestyle of hiking, climbing, and other outdoor recreational activities. This case demonstrates how Lyme carditis must be a foremost consideration in a patient with new-onset conductive heart disease, particularly in patients without risk factors for other causes of atrio-ventricular block. A thorough travel and exposure history must be taken when Lyme carditis is suspected in patients presenting outside of areas where the disease is endemic.