A 35-year-old man presents to the emergency department with complaints of chest pain. The pain is described as 8 on a scale ranging from 1 to 10, retrosternal, and sharp in nature. lt radiates to the back, is worse with taking a deep breath and is improved by ieaning forward. On review of systems, he has noted a "flu-like illness" over the past several days. including fever, rhinorrhea, and cough. He has no medical history and is taking no medications. He denies tobacco, alcohol, or drug use. On physical examination. he appears in moderate distress from pain, with a blood pressure of 125/85 mm Hg, heart rate 105 bpm, respiratory rate 18/min, and ox- ygen saturation of 98% on room air. He is currently afebrile. His head and neck examination is notable for clear mucus in the nasal passages and a mildly erythematous oropharynx The neck is supple, with shotty anterior cervical lymphad- enopathy. The chest is clear to auscultation. Jugular veins are not distended. Cardiac examination is tachycardic with a three component high-pitched squeaking sound. Abdomi- nal and extremity examinations are norma