AimsBrugada syndrome (BrS) is an inherited channelopathy that predisposes to malignant ventricular arrhythmias and thereby syncope and sudden cardiac death. Prior studies characterizing BrS patients have used highly selected referral populations from tertiary centres and prevalence estimates have been carried out using electrocardiogram (ECG) surveys only. We aimed to identify and characterize all diagnosed BrS patients in Denmark (population 5.4 million).Methods and resultsBrugada syndrome patients were identified using several modalities including identification in all Danish tertiary referral centres, search in public health registries, contact to all cardiology departments in Denmark, and searching in a pedigree database for inherited heart disease used nationwide in Denmark. We identified 43 definite diagnosed BrS patients and 25 possible BrS patients, corresponding to a prevalence of 1.1 definite BrS cases per 100 000 inhabitants. Most definite BrS patients were men (86%) and the median age at diagnosis was 48 years. A total of 35 definite BrS patients (81%) had an implantable cardioverter defibrillator (ICD) implanted and of these 9 (26%) experienced appropriate shocks and 3 (8%) experienced inappropriate shocks during a median follow-up of 47 months. No patient died or experienced aborted sudden cardiac death during follow-up.ConclusionsWe report the first nationwide study of BrS patients. We found a low incidence of diagnosed definite BrS compared with estimates from ECG surveys. Follow-up data show a lower rate of inappropriate therapies in ICD carriers than that reported in previous studies.