In certain cases, atrial fibrillation may require emergency treatment to convert the arrhythmia to normal (sinus) rhythm, either with electrical cardioversion or with the administration of intravenous drugs, such as dofetilide or ibutilide.

Long-term treatment varies depending on the cause of the atrial fibrillation or flutter. Medication may include beta-blockers, calcium channel blockers, digitalis or other medications (such as anti-arrhythmic drugs) which slow the heartbeat or slow conduction of the impulse from the atria to the ventricles.

Medications may also include blood thinners, such as heparin or coumadin, to reduce the risk of a thromboembolic event such as a stroke.

Some selected patients with atrial fibrillation, rapid heart rates, and intolerance to medication may require a catheter procedure on the atria called radiofrequency ablation.

For most patients with atrial flutter, radiofrequency ablation is the current treatment of choice. Some patients with atrial fibrillation and rapid heart rates may need the radiofrequency ablation done not on the atria, but directly on the AV junction (i.e., the area that normally filters the impulses coming from the atria before they proceed to the ventricles).

Ablation of the AV junction leads to complete heart block. These patients then require a permanent pacemaker.

• A pulse that is too rapid or too slow may reduce the amount of blood the heart can pump and lead to syncope (fainting).
• Emboli to the brain (stroke) or elsewhere -- rare, but often treated with anticoagulation to reduce this risk.