Insights into atrial fibrillation

Atrial fibrillation is the most common clinically relevant heart rhythm disorder and is associated with increased morbidity and mortality. Most important risk factors for atrial fibrillation are high age, arterial hypertension, diabetes mellitus, heart failure and rheumatic heart disease. Chronic atrial fibrillation is classified as paroxysmal, persistent, long-standing persistent and permanent atrial fibrillation. Spontaneous conversion to sinus rhythm is observed in paroxysmal atrial fibrillation, whereas in persistent atrial fibrillation, pharmacological or electrical cardioversion is required in order to restore sinus rhythm. In permanent atrial fibrillation, the arrythmia is accepted by patient and physician and cardioversion is not attempted. Rate control only is thus applied in permanent atrial fibrillation, whereas in paroxysmal and persistent atrial fibrillation, addition rhythm control with anti-arrhythmic drugs and/or ablation is attempted if symptoms persist and age and co-morbidities do not pose contra-indications. Besides rhythm management, oral anticoagulation is the mainstay of therapy for most patients with atrial fibrillation. Risk scores such as the CHA2DS2-VASc score help to identify patients with a high risk of stroke and need for oral anticoagulation. The underuse of vitamin K antagonists in clinical practise is partly due to considerable disadvantages: an increased bleeding risk, a narrow therapeutic window and multiple drug interactions prompting frequent laboratory controls to assess an individual dosage. New oral anticoagulants targeting thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban and edoxaban) may replace warfarin in many patients with atrial fibrillation due to convincing data both on efficacy and safety as well as convenience. However, challenges remain with respect to lack of specific antidotes and high costs.