What results can be expected from a successful cardioversion?

Back 2 normal rhythm. Successful cardioversion, by delivering electrical energy externally to the heart, should interrupt the abnormal rhythm, and "reset" the heart's rhythm by allowing the usual route of electricity generation/transmission to take over again. Any symptoms caused by the irregular rhythm (palpitations, shortness of breath, fatigue, chest pressure, dizziness) should immediately vanish at that point.
Rhythm. For cardioversion from atrial fibrillation to normal sinus rhythm success would be restoration of normal conduction. Patient may notice decreased palpitations, less fatigue, less dizziness, less shortness of breath and other symptoms.