P6585Number of ECG leads and prognosis of spontaneous type 1 Brugada syndrome

Abstract

Abstract Introduction Brugada syndrome (BrS) is an inherited arrhythmia syndrome with an increased risk of sudden cardiac death (SCD). The recent single lead-based diagnosis of Brugada syndrome recommended criterion may lead to overdiagnosis of Brugada syndrome and overestimation of the risk of SCD. Objective We aim to investigate the value of a single lead diagnosis in spontaneous type 1 ECG Brugada patient and to investigate the association between the number of ECG leads with a spontaneous type 1 ST elevation and the arrhythmic risk. Methods Consecutive patients affected with BrS were recruited in a multicentric prospective registry in France (15 centers) between 1994 and 2016. A total of 1613 patients affected by the Brugada syndrome were enrolled. For this specific study, only patient with a spontaneous type 1 BrS were enrolled (n=505). Data were prospectively collected with an average follow-up of 6.5±4.7 years. ECGs were reviewed by 2 physicians blinded to clinical status. Type 1 ST elevation was defined by ≥2 mm J-point elevation with coved ST segment and negative T wave. Results A total of 505 patients with a spontaneous type 1 BrS (mean age 46±15 years, 398 males, 79%) were enrolled. 117 patients (23%) were symptomatic at baseline (32 (6%) aborted SCD, 85 (17%) syncope). Implantable cardiac defibrillator (ICD) was implanted in 191 patients (38%). Brugada ECG pattern was found in 1 lead in 250 patients (50%, group 1), in 2 leads in 227 patients (45%, group 2) and in 3 leads in 28 patients (5%, group 3). Groups were comparable in term of clinical presentation except for group 3 who presented more frequently an early repolarization pattern (n=19 (8%) in group 1, n=15 in group 2 (6%) and n=7 (25%) in group 3, p=0.02) and more frequently QRS fragmentation (n=6 (2%) in group 1, n=3 in group 2 (1%) and n=3 (11%) in group 3, p=0.03). During follow-up, 46 (9%) patients presented an arrhythmic event: 22 (9%) in group 1 (4 SCD, 14 appropriate ICD therapy, 4 ventricular arrhythmias), 22 (10%) in group 2 (6 SCD, 11 appropriate ICD therapy, 5 ventricular arrhythmias) and 2 (7%) in group 3 (1 SCD, 1 appropriate ICD therapy). Patients with type 1 BrS pattern in 2 or 3 ECG leads had not a significantly higher rate of arrhythmic events than patients with type 1 BrS pattern in only 1 ECG lead (HR: 1.1; 95% CI: 0.6–1.9 for group 2 and HR: 0.7; 95% CI: 0.2–3 for group 2; p=0,087). Conclusion In the largest cohort of BrS patients ever described, the prognosis of Brugada syndrome with a spontaneous ECG pattern does not appear to be affected by the number of leads required for diagnostic.