Review Question - QID 215076

A 65-year-old woman presents to the emergency department with shortness of breath. She was previously able to jog 1.5 miles every day but is now unable to take more than 20 steps without sitting to catch her breath. She has no history of coronary artery disease. She has a history of breast cancer in remission for which she completed a treatment course 5 years ago that included cyclophosphamide, doxorubicin, and trastuzumab. She also has diabetes mellitus, for which she has been taking metformin and pioglitazone for 10 years. She was recently diagnosed with hypertension and started on amlodipine. She has never smoked and denies illicit drug use. The patient’s temperature is 97.8°F (36.6°C), blood pressure is 142/80 mmHg, pulse is 76/min, and respirations are 20/min. Physical exam is notable for bibasilar crackles on chest auscultation, jugular venous pressure of 12 cm H2O, and 2+ pitting edema in the lower extremities. An echocardiogram reveals a left ventricular ejection fraction of 40%. Which medication is most likely responsible for her symptoms?