A 32-year-old man presented to the emergency department with recent onset chest pressure and dyspnea. He reported having a flu-like illness one week prior. On exam, his heart rate was 108 and regular, blood pressure was 105/70, and he had a pericardial rub and basilar rales. His troponin T level was elevated at 12. An electrocardiogram showed abnormal findings. The patient is likely experiencing myocarditis, which can develop after a viral illness, and immunosuppressive therapy with prednisone and azathioprine is least likely to improve his left ventricular function over the next six months.