[Therapy of atrial fibrillation with class III anti-arrhythmia agents]

Medical treatment of atrial fibrillation has been carried out most frequently with digoxin, quinidine, propafenone or flecainide. In spite of unequivocal efficacy, the use of class I antiarrhythmic agents is the subject of considerable controversy. In addition to increased mortality in patients with ventricular arrhythmias after myocardial infarction, proarrhythmic effects with flecainide have also been described in patients with supraventricular arrhythmias. A meta-analysis of long-term treatment of atrial fibrillation with quinidine disclosed that the mortality in those treated with quinidine at 2.9% was significantly higher than those receiving placebo at 0.8%. In consideration of the prevailing uncertainty with the use of class I antiarrhythmic agents, class III antiarrhythmic drugs such as sotalol and amiodarone have been administered for supraventricular arrhythmias with increasing frequency. Treatment of atrial fibrillation with sotalol Sotalol is a noncardioselective beta-adrenergic receptor blocker with antiarrhythmic properties of class III. This drug prolongs the duration of the action potential and the refractory periods in atrial and ventricular myocardium and slows the AV-conduction as well as the sinus node rate. On oral administration, there is good resorption and a half-time of seven to 18 hours. The effective oral dose varies between 80 and 320 mg/12 hours. For conversion of acute supraventricular arrhythmias, an i.v. bolus of 0.5 to 1.5 mg/kg has been used. The results of clinical studies with sotalol in the treatment of atrial fibrillation are shown in Table 1.(ABSTRACT TRUNCATED AT 250 WORDS)