A Patient with Atrial Fibrillation: Shock now?

A 62 yo male with a previous history of paroxysmal atrial fibrillation presents to the emergency department with a rapid irregular heart beat and a complaint of palpitations, that started 2 hours previously.
His ECG is shown below.

The patient is haemodynamically stable and is not greatly distressed by the palpitations. He  is not on any anticoagulation.
Here are some important questions to answer in relation to this patient:

1. Do we shock this patient now, or give the patient 24 hours to potentially self-revert?
2. We know that if we shock early, we are doing so, to a number of patients who would self revert. Should we send the patient home and get them to come back the next day?
3. Are there any risks in waiting  for 24 to 48 hours, or is the risk of stroke equal during the first 48 hours?

​Watch the video lecture below for all the answers (From Cardiac Bootcamp).