A 19-year-old male with no significant medical history presented to the Emergency Department with persistent chest pain and worsening fever over five days. The 12-lead electrocardiogram (ECG) showed sinus rhythm, elevation of the ST segment in the inferior leads, and slight depression in V1-V2. Laboratory tests revealed elevated cardiac enzymes (hs-TnI 11698 pg/ml) and a mild increase in inflammatory markers. Echocardiography demonstrated normal morpho-functional parameters and a mild pericardial effusion. The patient was admitted to the Cardiovascular Intensive Care Unite with a diagnosis of myopericarditis.
Treatment with ibuprofen and colchicine led to a gradual improvement in cardiac enzymes and inflammatory markers. Microbiological exams showed IgM positivity for Coxiella burnetii, suggesting a possible zoonotic origin. Cardiac Magnetic Resonance Imaging (MRI) revealed signs of myocardial edema and non-ischemic late gadolinium enhancement (LGE).
As the myopericarditis was uncomplicated, no immunosuppressive/modulatory treatments were administered. Coronary CT confirmed the integrity of the epicardial coronary circulation. One month later, the patient was asymptomatic with no recurrence of fever or chest pain. Pericardial effusion resolved, and laboratory and instrumental findings were normal.
The cause of myopericarditis was attributed to Coxiella burnetii, an intracellular bacterium with reservoirs in domestic animals. Transmission occurs through contact with urine, feces, unpasteurized milk, or infected animal placentas. Clinical presentation varies from asymptomatic to flu-like symptoms or organ involvement. The heart can be affected in both endocarditic and, rarely, myocarditic forms.
In conclusion, this case represents an infectious myocarditis caused by Coxiella burnetii, confirmed by antibody positivity and a favorable response to anti-inflammatory and antibiotic therapy.
In the literature, few cases of myocarditis due to Coxiella burnetii are reported, and it is a rare complication of Q fever. However, it is an entity that exists and should be considered in the appropriate clinical-anamnestic context.