Diagnostic Value and Safety of Flecainide Infusion Test in Brugada Syndrome

Brugada Syndrome is an inherited arrhythmogenic disease responsible for life-threatening arrhythmias and sudden cardiac death in young individuals with structural normal heart. It is characterized by a peculiar ECG pattern, but this pattern could be intermittent. The infusion of sodium channel blockers (flecainide, ajmaline, procainamide) is used to unmask a concealed ECG pattern, thus providing an essential contribution to the diagnosis of this condition. In the current clinical practice in USA, only procainamide is used for diagnostic purposes; however in Europe only ajmaline and flecainide, available as iv formulations, are widely used. European and Japanese studies have demonstrated that the use of flecainide harbors less risks of adverse events in patients and may have a higher accuracy in unraveling the presence of the disease. In the present study the investigators propose to use flecainide infusion test in the Cardiovascular Genetics Program at NYUMC, in order to assess its sensitivity and specificity in diagnosing the disease and compare the incidence of adverse events to that observed during procainamide use. Additionally, the investigators propose to extend the study protocol to patients with a suspect diagnosis of Arrhythmogenic Right Ventricular Tachycardia (ARVC), due to the possible overlap between the two conditions. The study has the following aims: 1. To demonstrate the higher sensitivity and specificity of flecainide iv infusion compared to procainamide infusion for the diagnosis of Brugada Syndrome. 2. To demonstrate that flecainide is equally safe or safer than procainamide to use for diagnosing Brugada Syndrome. 3. To demonstrate that flecainide has high sensitivity and specificity in diagnosing also some patients with early stage Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC).