A physical therapist is working with a patient who has a his…

A physical therapist is working with a patient who has a history of cardiac arrhythmias. During the session, the patient stops responding to questions, appears to have weakness of their right side, and seems confused. The therapist sits the patient down and calls Emergency Medical Services (EMS). By the time EMS arrives 10 minutes later, all symptoms have resolved. Which of the following diagnoses is most likely?