How long does someone have to say hospitalized after cardioversion?

Out patient. Elective cardioversion is an out pt procedure. The anesthesia is the rate limiting step. If pts recover as expected then pts are discharged a couple of hrs after the cardioversion.
Usually few hours. If it is elective cardioversion, you can go home as early as 1-2 hours.
2 hours. We often monitor the patient for a brief period to make sure they are stable and then discharge them home quickly. Assuming that the cardioversion was elective of course.