Differences in clinical significance of atrial tachyarrhythmias in idiopathic ventricular fibrillation vs Brugada syndrome: A multicenter study

Background Atrial tachyarrhythmias (ATAs) are the primary cause of inappropriate implantable cardioverter-defibrillator (ICD) therapy in patients with idiopathic ventricular fibrillation (IVF) and are associated with decreased quality of life and increased mortality. Nonetheless, the incidence of ATAs in IVF cases has not been clarified. Objective The study sought to determine the incidence and clinical significance of ATAs in patients with IVF compared with those with Brugada syndrome (BrS). Methods Patients diagnosed with IVF or BrS and receiving ICDs in 6 hospitals were enrolled between February 1997 and July 2020 to compute data regarding the incidence of ATAs, appropriate/inappropriate ICD therapy frequency, and independent predictors of ATAs. Results Overall, 137 patients (51 in the IVF group and 86 in the BrS group) were enrolled. ATAs were detected in 22 (43.1%) patients in the IVF group and 17 (19.8%) in the BrS group (P = .006). Inappropriate ICD therapies due to ATAs were more frequently observed in the IVF group than in the BrS group (12 [23.5%] vs 7 [8.1%]; P = .020). Conversely, there was no significant difference in appropriate ICD therapies between the IVF and BrS groups (14 [27.5%] vs 23 [27.1%]; P = 1.000). Cox regression analysis revealed no predictive factors for the development of ATAs in the IVF group. Conclusion ATA events were observed more frequently in patients with IVF than in those with BrS, and ATAs led to inappropriate ICD therapy in patients with IVF. Clinicians need to consider the recurrence of not only ventricular arrhythmias, but also the development of atrial arrhythmias for better management of IVF cases.