A woman in her 30s with a history of gestational diabetes and hypertension presented to the ED with respiratory distress. She had no known cardiac or pulmonary disease. Progressively worsening dyspnea, including exertional and nocturnal dyspnea, began 1 month prior to presentation. At that point, she had been diagnosed as having an upper respiratory infection with fevers. Two weeks prior to presentation, the patient was treated with antibiotics for possible sinusitis without improvement. The patient did not report chest pain at any time.