Atrial fibrillation is a common arrhythmia which requires electrical cardioversion in many patients in order to regain sinus rhythm. In a previous retrospective study a complication of acute renal failure was found in 17% of the patients after cardioversion.(The incidence and prognosis of renal dysfunction following cardioversion of atrial fibrillation. Helman Y,...Gilon D et al:Cardiology 2013;124(3);184-9.) Another complication previously described after cardioversion is pulmonary edema.