Fulminant Lyme myocarditis without any other signs of Lyme disease in a 37-year-old male patient with microscopic polyangiitis-a case report.

A severely reduced LVEF can be the primary manifestation of Lyme disease even without typical systemic findings and can have a favourable prognosis with antibiotic treatment. A thorough workup for Lyme carditis is required in patients with unexplained heart failure, particularly with EMB, especially in immunosuppressed patients.