DC cardioversion is a treatment by which a pulse of electricity is passed across the heart in order to convert atrial fibrillation into the normal (sinus) rhythm.
This is done under general anaesthetic and requires you to be nil by mouth for 6 hours beforehand.
It is important that blood thinning (anticoagulation) has been at a treatment level for at least 3 weeks beforehand. If you are on warfarin then ideally you should have at least 3 INR tests each one week apart with a reading of 2 or more before going ahead with a cardioversion. If you are taking a novel oral anticoagulant such as dabigatran, rixroxaban or apixaban then it is essential that you have been taking this as prescribed for at least 3 weeks before the procedure.
If there has been a lapse in blood thinning then it is often possible to go ahead, but a trans-oesophageal echocardiogram (ultrasound scan from the gullet) is needed using a small probe to make sure that there is no evidence of blood clot within the heart.
DC cardioversion is often not a long term solution and AF may recur. If restoration of sinus rhythm resulted in improvement in quality of life but atrial fibrillation recurs then catheter ablation of atrial fibrillation can be considered.