381: The Tick and the Ticker: A Rare Case of Lyme Perimyocarditis

INTRODUCTION: Lyme disease can cause significant cardiovascular complications such as channelopathies, cardiomyopathy, or peri-myocarditis (PM) We present a case of PM in a young patient who was managed with timely initiation of antibiotics METHODS: A 21-year-old male with no significant medical or family history presented to the hospital with chest pain He was in his usual state of health when he developed a sudden onset of dull, substernal chest pain, radiating to the bilateral upper extremities On presentation, his physical examination was unremarkable Electrocardiogram demonstrated diffuse ST-segment elevations in the precordial leads Laboratory investigations were notable for a troponin elevation of 12 ng/ml Echocardiogram was unremarkable The patient was admitted to the hospital for possible PM and was initiated on colchicine therapy He underwent cardiac magnetic resonance imaging, which revealed a patchy intramural myocardial enhancement consistent with myocarditis Workup included testing for COVID-19, Epstein-Barr virus, Coxsackie virus, which was negative, and rheumatologic workup was negative Upon further investigation, it was revealed that the patient had a tick bite a few weeks ago Subsequently, he had a positive serological test for Lyme disease with positive IgM antibodies which were confirmed on the immunoblot test PM was thereby attributed to Lyme disease, and the patient was treated with doxycycline for 21 days with complete resolution RESULTS: PM is characterized by varying disease manifestations and may rapidly deteriorate into a lifethreatening condition leading to catastrophic outcomes such as arrhythmias, cardiac arrest, or cardiogenic shock The etiology of PM is broad and can be due to a variety of insults Lyme carditis occurs when the bacteria disseminate and affect the cardiac muscle and the conduction system Although the predominant abnormality is heart block, PM is a rare manifestation of Lyme carditis Physicians should have a high degree of clinical suspicion to diagnose this condition to prevent catastrophic cardiovascular outcomes Timely introduction of antibiotic therapy is essential to prevent fatal outcomes