Quinidine treatment of chronic lone atrial fibrillation

Patients with chronic lone atrial fibrillation (LAF) were treated with quinidine according to a special schedule to establish sinus rhythm and prevent recurrences. Twenty‐seven patients following this schedule were identified retrospectively to prevent relapses, quinidine had been continued in 25 patients in doses 100 mg qid lower than those used for conversion. In 8 of the latter group, quinidine had to be discontinued or reduced. All patients converted to sinus rhythm. If well tolerated, quinidine prevented recurrence of LAF in 75% of those on long‐term (mean follow ‐ up 3.5 years) prophylaxis. After discontinuation of quinidine in 8 patients, LAF recurred in all but one patient. Side effects were observed in 22% of the patients and precluded continuation of the prophylaxis in 15%. No incidence of torsade de pointes was encountered.