[Electrical cardioversion for atrial fibrillation]

Abstract

Electrical cardioversion ist often the treatment of first choice for restoring sinus rhythm in patients with atrial fibrillation. This article reviews the management of patients undergoing electrical cardioversion. As risk of formation of an intra-atrial thrombus formation is low after a short duration of AF (less than 48 h), immediate cardioversion can be performed in these patients (except those with a high risk for thrombembolic events). However, if the AF has lasted for more than 48 hours, patients have to be treated either with anticoagulants for at least three weeks or an atrial thrombus has to be excluded by transesophageal echocardiography. Both options achieve the same short- or long-term success rate for cardioversion. Cardioversion is probably safe even if there are spontaneous echocardiographic contrasts as signs of potential thrombogenic slowing of atrial blood flow, but individual factors of risk/indication have to taken into account. Success rate of cardioversion depends on various patient characteristics as well as on some technical variables, biphasic instead of monophasic shocks being more effective. If there is an early recurrence of AF after initially successful cardioversion, administration of amiodarone (for 4 weeks) increases the success rate of subsequent cardioversion. After successful cardioversion subsequent antiarrhythmic therapy can reduce recurrence of AF. Thrombembolic complications are more frequent within the first few days after cardioversion. Indication for and duration of post-cardioversion anticoagulation depends on individual characteristics (CHADS(2) score) as well as on the duration of the preceding episode of AF.