New-onset atrial fibrillation as first clinical manifestation of latent Brugada syndrome: prevalence and clinical significance

• Published in: European heart journal 2009-12, Vol.30 (24), p.2985-2992
• Main Authors: Pappone, Carlo, Radinovic, Andrea, Manguso, Francesco, Vicedomini, Gabriele, Sala, Simone, Sacco, Francesco Maria, Ciconte, Giuseppe, Saviano, Massimo, Ferrari, Maurizio, Sommariva, Elena, Sacchi, Stefania, Ciaccio, Cristiano, Kallergis, Eleftherios M., Santinelli, Vincenzo
• Format: Article
• Language: English
• Subjects: Adult; Anti-Arrhythmia Agents - therapeutic use; Atrial fibrillation; Atrial Fibrillation - etiology; Brugada syndrome; Brugada Syndrome - complications; Brugada Syndrome - drug therapy; Brugada Syndrome - genetics; Electrocardiography; Female; Flecainide - therapeutic use; Genetic Testing; Humans; Male; Middle Aged; Muscle Proteins - genetics; Mutation - genetics; NAV1.5 Voltage-Gated Sodium Channel; Sodium Channels - genetics; Sudden cardiac death
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/ehp326

Aims To evaluate the prevalence, clinical significance, and prognosis of latent Brugada syndrome (BrS) in patients with new-onset atrial fibrillation (AF) unmasked by class 1C antiarrhythmic drugs. Methods and results Between January 2000 and June 2008, all consecutive patients with new-onset AF, who after flecainide exhibited typical Brugada ECG pattern, underwent electrophysiologic, pharmacologic, and genetic testing. Among 346 patients [median age 53 years; interquartile range (IQR), 15], 11 (3.2%; median age 51 years; IQR, 19) diagnosed as lone AF exhibited typical Brugada ECG pattern. Genetic testing was negative. Ventricular tachycardia/ventricular fibrillation (VT/VF) was induced by electrophysiologic testing (five patients) or during flecainide infusion (one patient). Six patients with type 1 ECG pattern and inducible VT/VF underwent ICD implantation. During a median follow-up of 31.5 months (range: 10–85) after ICD implantation, three patients developed BrS and one of them experienced VF. Patients without ICD (five patients) remained asymptomatic during a median follow-up of 74 months. Persistent type 1 pattern occurred only in the three patients who developed BrS. Conclusion This study, for the first time, reveals the prevalence of latent BrS in patients with new-onset lone AF, which may precede VT/VF. Persistence of type 1 and ventricular tachyarrhythmias inducibility represents a marker of electrical instability leading to sudden death.