Review Question - QID 210602

A 55-year-old man presents to the emergency department with shortness of breath and fatigue. His symptoms began insidiously and progressively worsened over the course of a month. He becomes short of breath when climbing the stairs or performing low-intensity exercises. He also needs to rest on multiple pillows in order to comfortably sleep. A few weeks ago, he developed a fever, malaise, and chest pain. Medical history is significant for hypertension, hypercholesterolemia, type 2 diabetes, and bariatric surgery performed 10 years ago. He is taking lisinopril, atorvastatin, and metformin. He drinks alcohol occasionally and does not smoke. He tried cocaine 3 days ago for the first time and has not used the illicit drug since. His temperature is 98.7°F (37°C), blood pressure is 107/68 mmHg, pulse is 88/min, respirations are 16/min, and oxygen saturation is 95% on room air. Physical exam is significant for bibasilar crackles, an S3 heart sound, and a laterally displaced cardiac apex. He has normal muscle tone throughout, 2+ reflexes, and an intact sensory exam. Which of the following is most likely the cause of this patient's symptoms?