A 32-year-old man with no significant past medical history is brought to the emergency department by his partner due to worsening shortness of breath. The symptoms began abruptly three days ago with exertional dyspnea, which has rapidly progressed to dyspnea at rest, orthopnea requiring three pillows, and a non-productive cough. This morning, he coughed up pink, frothy sputum. He reports feeling generally unwell for the past two weeks with intermittent fevers and chills, which he attributed to the flu. He had a dental cleaning one month ago but did not receive antibiotic prophylaxis. His family history is notable for his father having a “heart murmur.” He denies illicit drug use and takes no medications.