Reversible atrioventricular block and the importance of close follow-up: Two cases of Lyme carditis.

Lyme carditis is an uncommon presentation of the early-disseminated phase of Lyme disease, although it is recognizable and often curable. Because of its rarity, diagnosing Lyme carditis requires a high level of suspicion, especially when young patients in certain endemic areas present with symptoms of bradycardia and/or evidence of high-degree atrioventricular (AV) block. Temporary cardiac pacing along with antibiotic therapy has been shown to aid in the management of Lyme carditis until symptoms and conduction blocks have resolved. Herein, we report two cases of Lyme carditis-induced AV block that were successfully managed and reversed with temporary cardiac pacing and antibiotics. In order to monitor for any late sequela that may arise, we also recommend close follow-up for patients treated for Lyme carditis with high-degree AV block. <Learning objective: Lyme carditis manifests as a conduction system disease, predominantly involving the atrioventricular (AV) node. It can present without the classical signs of Lyme disease. It is critical to have a high suspicion of Lyme carditis in patients who present with symptoms of bradycardia or high-degree AV block in high prevalence areas. Early initiation of antibiotics, along with external temporary pacing, dramatically improves mortality rates. Close follow-up is important in patients that develop high-degree AV block.>.