Review Question - QID 213761

A 57-year-old man presents to the emergency department with dyspnea and shortness of breath. He has a past medical history of a "heart condition" being managed by his cardiologist. He states he feels a strange sensation in his chest that started a few hours ago. The patient otherwise denies any chest pain. His temperature is 97.0°F (36.1°C), blood pressure is 109/70 mmHg, pulse is 123/min, and respirations are 15/min. Physical exam is notable for the finding in Figure A. Bilateral clear breath sounds are heard on auscultation. The patient's abdomen is non-tender, and he demonstrates no pitting lower extremity edema. An ECG is performed as seen in Figure B. Which of the following is a complication of the medication used to treat this patient's underlying diagnosis?