A 68-year-old woman comes to the physician 12 hours after an episode of blindness in her left eye that lasted 15 minutes. She takes no medications. Blood pressure is 138/80. Motor and sensory examination are normal. Pupils are equal, round, and reactive to light. Visual fields are full. Ocular movements are intact. Funduscopic examination shows a refractile body. Which of the following is the most appropriate next best step in diagnosis?
CT angiography
Slit-lamp examination
Tonometry
Transesophageal echocardiography
Ultrasound
