Rare case of fulminant myocarditis in a patient with rickettsia infection

We report a rare case of fulminant myocarditis caused by Rickettsia conorii infection in a 31-year-old previously healthy male from rural Greece. The patient presented with acute chest pain, fever, and an insect bite eschar. Initial electrocardiography (ECG) demonstrated inferior ST-segment elevation, and coronary angiography excluded obstructive coronary artery disease. Within 24 h, the patient deteriorated to hemodynamic collapse, with left ventricular ejection fraction (LVEF) declining to 20-25%. Management included doxycycline, empirical broad-spectrum antibiotics, intravenous corticosteroids, and aggressive diuresis. Serological confirmation of R. conorii infection (IgM titer 1:64) directed targeted antibiotic monotherapy. Cardiac magnetic resonance (CMR) imaging performed two days post-discharge confirmed acute myocarditis per the 2018 Updated Lake Louise Criteria, with extensive late gadolinium enhancement (LGE) involving 28% of LV mass. LVEF recovered to 56% within weeks. This case highlights the potential for R. conorii to precipitate fulminant myocarditis even in immunocompetent young patients, underscoring the importance of clinical suspicion in endemic regions.