Review Question - QID 213824

A 35-year-old woman presents to the emergency department after fainting. She was visiting her family when she fainted upon arriving at their house. She woke up 1 minute later and was at her baseline mental status. Since then, she has felt persistently light-headed and weak since the event. She almost fainted again while in the emergency department. The patient has a past medical history of obesity and recently had knee surgery with her knee currently immobilized in a brace. She is currently taking metformin, oral contraceptive pills, and sumatriptan. Her temperature is 99.3°F (37.4°C), blood pressure is 72/48 mmHg, pulse is 177/min, respirations are 29/min, and oxygen saturation is 90% on room air. Physical exam is notable for an anxious young woman who is unable to walk without feeling light-headed. An ultrasound is performed demonstrating a dilated right ventricle with septal bowing and a hyperdynamic left ventricle. Which of the following is the most appropriate next step in management?