Lyme Carditis Presenting As Idiopathic Myocarditis: Prompt Empirical Treatment Despite Negative Serology

Lyme carditis is a rare but serious complication of Borrelia burgdorferi infection, which can lead to fatal arrhythmias if it is not treated promptly or is misdiagnosed. Lyme carditis can mimic common cardiac conditions, causing diagnostic delays and poor outcomes. In this article, we report a case of Lyme carditis that was initially diagnosed as idiopathic myocarditis, and we highlight the consequences of delayed diagnosis. This case further underscores the importance of timely insertion of a temporary transvenous pacemaker in specific patients at high risk of asystole. The case also sheds light on the need for vigilant interpretation of serologic testing results when clinical suspicion is high.