Effects of electrophysiologic-guided therapy with Class IA antiarrhythmic drugs on the long-term outcome of patients with idiopathic ventricular fibrillation with or without the Brugada syndrome

Introduction: Implantation of a implantable cardioverter defibrillator (ICD ) is viewed universally as the "gold standard" therapy for patients with id iopathic ventricular fibrillation (VF), We sought to study the long-term va lue of electrophysiologic (EP)-guided therapy with Class IA antiarrhythmic drugs in patients with idiopathic VF with or without the Brugada syndrome. Methods and Results: We performed EP studies in 34 consecutive patients who had idiopathic VF with (n = 5) or without (n = 29) the Brugada syndrome. A ll patients with inducible sustained polymorphic ventricular tachycardia (S PVT) or VF underwent repeated EP evaluation after oral administration of a Class IA antiarrhythmic drug (mainly quinidine), Patients rendered noninduc ible received this therapy on a long-term basis, SPVT/VF were induced in 27 (79.4%) patients at baseline studies. Class IA drugs effectively prevented induction of SPVT/VF in 26 (96%) patients, Of the 23 patients treated with these medications, no patient died or had a sustained ventricular arrhythm ia during a mean follow-up period of 9.1 +/- 5.6 years (7 to 20 years in 15 patients). Two deaths occurred in patients without inducible SPVT/VF at ba seline studies who had been treated empirically. Conclusion: Our results suggest that EP-guided therapy with Class IA agents is a reasonable, safe, and effective approach for the long-term management of patients with idiopathic VF, A randomized prospective study of EP-guide d Class IA therapy in patients with ICDs seems warranted.