Well, it's a normal to experience apprehenision and vigilence following an event such as described and atrial fibrillation in normal healthy adults is far more common than one might imagine. To primarily address your question of whether to wait for spontaneous resolution, although the AF is not considered to be life-threatening in of itself in these particular instances, persons who have historically required intervention to restore normal sinus rhythm will find it ultimately necessary in most subsequent events. I will state, however, that several maneuvers in otherwise healthy persons can be performed to determine whether spontaneous recovery can be induced.

The valsalva maneuver is performed by tensing the stomach muscles and forcefully pushing air against a closed glottis, similar to the natural action induced when straining during a bowel movement. The activity should be initiated and maintained for a period of about 10 seconds or so, followed by release and normal breathing. If recovery doesn't ensue, it can be repeated about three times.

The dive reflex is a natural occurrence in all mammals when submerging underwater, where water temperature and pressure cause changes in blood pressure and blood returning to the heart. It can be invoked artificially by immersing the face in very cold water for 10 seconds or so, followed by pressing gently on the eyes for about 30 seconds. Realize that one need not keep their face in cold water while pressing upon the eyes. This is somewhat more complicated to perform than the valsalva maneuver, but can produce spontaneous recovery from uncomplicated AF in some instances.

If these actions fail to initiate recovery to normal sinus rhythm, then medical attention should be sought but you should in all instances try to make certain that someone is aware of your circumstances prior to trying these maneuvers and that medical attention may possibly be necessary to ultimately resolve the issue.

Best regards and Good Health