The current study is designed to assess the efficacy and safety of iv AZD7009 in conversion from AF

Inclusion Criteria:

• Clinical indication for cardioversion of Atrial Fibrillation. Effective oral anticoagulation according to local routines or a TEE without any finding of intracardial thrombus or signs of thrombogenecity

Exclusion Criteria:

• Clinically significant sinus and/or AV node dysfunction. Serum or plasma potassium <3.8 mmol/L or >5.0 mmol/L. QTc(Bazett) >450 ms. Any QRS duration >150 ms