Use of β-blockers in atrial fibrillation

Atrial fibrillation is the most common arrhythmia in the general population and is frequently associated with organic heart disease. β-adrenoceptor antagonists (β-blockers) are very effective in preventing atrial fibrillation after coronary artery bypass surgery. It has been shown recently that the β-blocker metoprolol controlled release/extended release (CR/XL) is also effective in maintaining sinus rhythm after conversion of atrial fibrillation. There is concern that class I antiarrhythmic drugs, such as quinidine, disopyramide, and flecainide in particular, may increase mortality. The risk of proarrhythmia associated with β-blocker treatment is very low. Therefore β-blockers, such as metoprolol CR/XL, may be the first line of treatment to maintain sinus rhythm, especially after myocardial infarction and in patients with chronic heart failure and in those with arterial hypertension. In patients with persistent atrial fibrillation, AV-nodal conduction-slowing drugs, such as calcium channel antagonists and β-blockers are used to control the ventricular rate during atrial fibrillation. Several studies clearly show that β-blockers alone, or in combination with digoxin are very effective in controlling the ventricular rate at rest and during exercise. β-blockers are effective in maintaining sinus rhythm and controlling the ventricular rate during atrial fibrillation. Given these effects and their favorable effects on mortality, β-blockers should be considered as first-line agents in the management of patients with atrial fibrillation.