A 48-year-old woman calls 911 and is brought to the emergen…
A 48-year-old woman calls 911 and is brought to the emergency room complaining of a sudden onset of dyspnea. She reports she was standing in the kitchen making dinner, when she suddenly felt as if she could not get enough air, her heart started racing, and she became lightheaded and felt as if she would faint. She denied chest pain or cough. Her medical history is significant only for gallstones, for which she underwent a cholecystectomy 2 weeks previously. The procedure was complicated by a wound infection, requiring her to stay in the hospital for 8 days. She takes no medications regularly, only for acetaminophen as needed for pain at her abdominal incision site.On examination, she is tachypneic with a respiratory rate of 28 breaths per minute, oxygen saturations 84% on room air, heart rate 124 bpm, and blood pressure 118/89 mm Hg. She appears uncomfortable, diaphoretic, and frightened. Her oral mucosa is slightly cyanotic, her jugular venous pressure is elevated, and her chest is clear to auscultation. Her heart rhythm is tachycardic but regular with a loud second sound in the pulmonic area, but no gallop or murmur. Her abdominal examination is benign, with a clean incision site without signs of infection. Her right leg is moderately swollen from mid-thigh to her feet, and her thigh and calf are mildly tender to palpation. Laboratory studies including cardiac enzymes are normal, her electrocardiogram (ECG) reveals only sinus tachycardia, and her chest X-ray is interpreted as normal. What is the most likely diagnosis?