Efficacy of Quinidine in High-Risk Patients With Brugada Syndrome

Abstract

Background-Automatic implantable cardioverter-defibrillator therapy is considered the only effective treatment for high-risk patients with Brugada syndrome. Quinidine depresses I to current, which may play an important role in the arrhythmogenesis of this disease. Methods and Results-The effects of quinidine bisulfate (mean dose, 1483Ϯ240 mg) on the prevention of inducible and spontaneous ventricular fibrillation (VF) were prospectively evaluated in 25 patients (24 men, 1 woman; age, 19 to 80 years) with Brugada syndrome. There were 15 symptomatic patients (including 7 cardiac arrest survivors and 7 patients with unexplained syncope) and 10 asymptomatic patients. All 25 patients had inducible VF at baseline electrophysiological study. Quinidine prevented VF induction in 22 of the 25 patients (88%). After a follow-up period of 6 months to 22.2 years, all patients are alive. Nineteen patients were treated with quinidine for 6 to 219 months (meanϮSD, 56Ϯ67 months). None had an arrhythmic event, although 2 had non-arrhythmia-related syncope. Administration of quinidine was associated with a 36% incidence of side effects that resolved after drug discontinuation. Conclusions-Quinidine effectively prevents VF induction in patients with Brugada syndrome. Our data suggest that quinidine also suppresses spontaneous arrhythmias and could prove to be a safe alternative to automatic implantable cardioverter-defibrillator therapy for a substantial proportion of patients with Brugada syndrome. Randomized studies comparing these two therapies seem warranted.

Impact of clinical and genetic findings on the management of young patients with Brugada syndrome

“…In the adult population hydroquinidine tends to be a safe alternative 28,29 but given the small number of patients and the relatively short follow-up in this cohort, larger-scale studies are needed.…”

The genetic basis of Brugada syndrome: A mutation update

“…The frequency of adverse complications of ICD therapy in BrS underscores the need for better risk stratification. Quinidine has been suggested as an alternative to ICD implantation due to its I to inhibitory effect (see Pathogenetic mechanism) and its VF inhibitory effect [Belhassen et al, 2004]. Due to the lack of prospective studies of treatment effects, quinidine cannot be used as first line therapy in BrS, but could be considered as an adjunctive therapy in high-risk patients with ICD complications [Mizusawa et al, 2006], or in children where ICD implantation is difficult.…”

Alcohol‐induced Ventricular Fibrillation in Brugada Syndrome

“…12) A number of reports have shown the effectiveness of quinidine in treatment of Brugada syndrome. [13][14][15][16][17][18][19] Because the typical features of Brugada syndrome were not observed in this case, it is unclear whether quinidine would have been effective. If VF storms occur despite the administration of quinidine, we are considering EPS and ablation under alcohol administration.…”