A 77-year-old man with a past medical history of myelodysplastic syndrome, coronary artery disease, hypertension, and chronic atrial fibrillation presented at the hematology outpatient clinic with progressive shortness of breath, weakness, and chest and back pain. Echocardiography was performed and the patient was diagnosed with severe pericardial effusion near the right ventricle. Pericardial drainage was performed. Erysipelothrix rhusiopathiae was isolated from the pericardial fluid. Complications of respiratory and renal failure developed during follow-up. The clinical and laboratory findings of vegetation on the tricuspid valve, pericardial effusion, and atrial fibrillation with a low heart rate suggested possible pancarditis. A multidisciplinary treatment approach with the cardiology and infectious disease departments was critical to successful management of this case.