Clinical challenge I: Control of recurrent symptomatic atrial fibrillation

Control of recurrent symptomatic atrial fibrillation should be directed at: (1) alleviation of symptoms associated with atrial fibrillation and (2) reduction of the risk of embolization. Approximately 50-60% of patients treated with conventional agents such as quinidine will develop recurrent atrial fibrillation in the first year of treatment. Because of this relapse rate and the side effects associated with quinidine and other type Ia antiarrhythmic agents, it is important to investigate the efficacy and safety of newer antiarrhythmic agents such as propafenone and sotalol. In our institution, 100 patients with recurrent symptomatic atrial fibrillation who had failed therapy with at least one type Ia agent were randomized to propafenone or sotalol. Propafenone and sotalol were equally effective in preventing recurrent atrial fibrillation at 6 and 12 months after onset of therapy independent of arrhythmia pattern or left atrial size. Both agents were well tolerated with only 10% of patients discontinuing therapy due to side effects. We combined data from this randomized study with a stepped care trial of propafenone and sotalol to examine risk factors for the development of recurrent atrial fibrillation. In patients treated with propafenone or sotalol, there was no significant difference in response to therapy based on age, gender, or aetiology of heart disease. Patients with dual-chamber pacing had improved maintenance of sinus rhythm as compared to those individuals without pacemakers. Left atrial size did not significantly influence the likelihood of maintaining sinus rhythm in these trials. Pharmacological management of the patient with recurrent symptomatic atrial fibrillation remains a difficult problem. Patient symptom severity and the clinical profile should be examined prior to instituting antiarrhythmic therapy in any given patient. These studies indicate that propafenone and sotalol are equally effective when used to maintain sinus rhythm in our population. As more data on the merits and risks of antiarrhythmic therapy for the treatment of atrial fibrillation become available, the role of propafenone and sotalol in the treatment of this disorder will be better understood.