Myocarditis with fulminant type 1 diabetes mellitus diagnosed by cardiovascular magnetic resonance imaging: a case report

BACKGROUND: Fulminant type 1 diabetes is a non-autoimmune disorder characterized by sudden onset. This complication is rarely associated with myocarditis, suggesting an involvement of viral infection. We report a patient with myocarditis who was admitted for fulminant type 1 diabetes and diagnosed using a combination of non-invasive techniques. CASE PRESENTATION: We describe the case of a 25-year-old Japanese man with fulminant type 1 diabetes complicated by myocarditis. The patient was admitted with flu-like symptoms and diabetic ketoacidosis, followed by chest pain the next day. Myocardial damage was suspected based on ST-segment elevation on electrocardiogram and elevation of cardiac enzymes. However, coronary angiography revealed no abnormality in the coronary arteries. We diagnosed myocarditis by a combination of echocardiography, cardiovascular magnetic resonance imaging (CMR), as well as Thallium-201 and Iodine-123 beta-methyl iodophenyl pentadecanoic acid (Tl-201 BMIPP and I-123 BMIPP) and myocardial imaging. More importantly, CMR revealed diffuse enhancement in the subepicardium of the left ventricle with late gadolinium enhancement, consistent with myocardial edema. The patient was successfully treated, received a two-week education program on diabetes and discharged without complication. CONCLUSIONS: The rapid onset and flu-like symptoms strongly suggest the involvement of viral infection in the pathogenesis of fulminant type 1 diabetes and myocarditis. While cardiac muscle biopsy is routinely performed, this case demonstrates that a combination of non-invasive techniques, especially CMR, may successfully diagnose myocarditis in patients with fulminant type 1 diabetes.