[Medicamentous prevention of symptomatic paroxysmal atrial fibrillation/flutter onset. Goals and design of the SOPAT Study. Executive committee of the investigators representing trial physicians].

The indication to treat symptomatic paroxysmal atrial fibrillation is discussed controversely. Successful medical treatment may result in the reduction of symptoms by improving hemodynamics in a reduction of thromboembolic events. However, several antiarrhythmic drugs are also known to increase the risk of proarrhythmic events. A randomized, double-blind, and placebo-controlled multicenter trial with 1000 patients to be recruited was designed to compare the effects of two antiarrhythmic drugs frequently used in Germany for the treatment of atrial fibrillation, Sotalol and the fixed combination of chinidin and verapamil (Cordichin). Patients with symptomatic paroxysmal atrial fibrillation/atrial flutter will be observed for a period of one year. The occurrence of paroxysmal atrial fibrillation is documented by transtelephonic ECG monitoring. Patients with document an ECG once daily, and recording is mandatory in case of symptoms. ECGs are transmitted to a central data base for analysis. This clinical trial is designed to answer the following questions: (1) What is the average rate of spontaneous events of symptomatic atrial fibrillation? (2) Is it possible to reduce the frequency of symptomatic events by chronic antiarrhythmic drug administration? (3) What is the long-term frequency for the occurrence of severe side-effects under antiarrhythmic medication? The primary endpoint is defined as the time to first recurrence of symptomatic arrhythmia after reaching steady-state plasma concentrations of the study medication. The trial started in November 1997 and is planned to be finished by the end of 1999.