Indications and limitations of class II and III antiarrhythmic drugs in atrial fibrillation.

In summary, the Class III antiarrhythmic agents amiodarone and sotalol are effective in restoring sinus rhythm in patients with chronic atrial fibrillation with a higher effectiveness of amiodarone. Both agents successfully prevent recurrent episodes of atrial fibrillation after electrical cardioversion and both can control heart rate in persistent atrial fibrillation. Amiodarone appears to be particularly suitable in patients with atrial fibrillation and concomitant congestive heart failure because it lacks clinically relevant negative inotropic activity. Both substances are also effective in controlling ventricular arrhythmias that are frequently present in patients with atrial fibrillation. Finally, both drugs possess antiadrenergic activity, which makes the substances particularly attractive in patients with coronary heart disease as the underlying cause of atrial fibrillation.