Oral flecainide is not sensitive enough to rule out Brugada- Syndrome

The Brugada syndrome is a heterogeneous genetic disease that predisposes one to lifethreatening ventricular tachyarrhythmia and sudden cardiac death (SCD). In this study, we sought to compare the efficacy of intravenous Procainamide versus oral Flecainide to unmask the typical electrocardiographic changes of this syndrome.Brugada syndrome/ Flecainide challenge test / IV procainamide challenge testFrom October 2001 to December 2010, we evaluated patients with the Brugada Type Electrocardiographic (ECG) pattern. In these patients, 104 patients (83%) were male. The mean age of the participants was 39.16±7 years (16 to 75), and the mean follow-up was 48±3 months. All of the subjects underwent IV Procainamide and oral Flecainide challenge test. Among these patients 19 patients had positive results. Nineteen patients had positive responses (15%); 18 of them were male (94.7%) and one of them was female. These 19 patients all had a positive Procainamide challenge test. Only 9 of these patients had a positive Flecainide test. In the diagnosed Brugada Syndrome patients, IV Procainamide had a 100% positive response rate in comparison to a 47.4% positive rate in oral Flecainide. Different Brugada challenge tests have different sensitivities in the diagnosis of BS. IV procainamide is more sensitive than oral Flecainide and the latter cannot be used solely to rule out BS.