16-85: Efficacy and safety of quinidine in patients with Brugada syndrome

Introduction: Pharmacological treatment of arrhythmias in Brugada syndrome (BrS) may be challenging due to contraindicated drugs. Quinidine is a class IA antiarrhythmic drug useful in this disease. The aim was to evaluate the efficacy and safety of quinidine in a large cohort of patients with BrS. Methods: Of a total of 367 patients with BrS in follow-up (43 ± 14 years; 74% male), 12 patients (3.3%) were treated with quinidine 300mg or hidroquinidine 250mg twice a day, according to availability. We analyzed the indications and the long-term outcome of this therapy. Results: After a follow-up of 85 ± 54 months, 6 patients (50%) underwent quinidine treatment due to paroxysmal atrial fibrillation (AF) and 6 patients (50%) due to ventricular fibrillation (VF). Four patients (67%) underwent AF ablation in which quinidine was started due to AF recurrence. Quinidine was started before AF ablation in 1 patient (17%) and 1 patient (17%) had no AF ablation. Although 4 patients (67%) had AF recurrence after quinidine, inappropriate ICD shocks were reduced. Two patients (33%) had respectively 6 and 7 episodes of ICD inappropriate shocks due to AF before quinidine. No inappropriate shocks had registered after quinidine (p < 0.01). In the VF group, quinidine was started after 4.4 ± 4.2 appropriate ICD shocks. Three patients (50%) had no recurrences of VF (p < 0.01). Two patients (33%) had 2 recurrences of VF and 1 patient had 9 more VF episodes with appropriate ICD shocks. There were no major adverse effects to quinidine, only 1 patient presented a mild allergic reaction. Basal characteristics and follow-up outcomes are shown in the table.