P6580Prevalence and clinical significance of latent Brugada syndrome in juvenile lone atrial fibrillation

Abstract

Abstract Introduction Brugada syndrome (BrS) cause about 20% of sudden cardiac death (SCD) in young healthy adults. Nearly 20% of Brugada patients develop supraventricular arrhythmias, mostly atrial fibrillation (AF). But whether lone AF may be the first clinical manifestation in young patients with latent BrS remains unclear. Purpose To estimate the prevalence and clinical significance of latent Brugada ECG pattern in young population (age ≤45 years) with lone AF. Methods A total of 78 patients with lone atrial fibrillation (mean age 35±7) were selected from 111 young patients with juvenile atrial fibrillation (age ≤45 years) between January 2015 and November 2017. All patients were clinically evaluated. Moreover 12 lead-24H Holter ECG and pharmacological class 1C antiarrhythmic drug (AAD) test were done for high suspicious cases of Brugada ECG. The diagnosis of Brugada ECG pattern was established according to the second consensus report criteria 2005 and since 2013, according to HRS/EHRA/APHRS expert consensus statement. Results According to the study protocol, we considered two groups of patients, group 1: 13 patients (16.7%; mean age 37±8) were diagnosed with type 1 Brugada ECG pattern (3 during class 1C AADs therapy and 10 induced by class 1C AAD test), group 2: 65 patients (83%; mean age 35±7) diagnosed as lone AF without type 1 Brugada ECG. The clinical characteristics of the two groups are described in table 1. Regarding to group 1, two patients had positive electrophysiological study with subsequent ICD implantation and genetic test for SCN5A mutation was positive in 3 patients. Table 1. G1, G2 clinical characteristics Patients characteristics Group 1 (n=13) Group 2 (n=65) P value Mean age (years) 37±8 35±7 0.42 Gender (Male %) 7 (54%) 54 (83%) 0.02 Family history of BrS 2 (15%) 0 (0%) 0.03 Family history of SCD 1 (8%) 1 (1.5%) 0.20 Syncope 4 (31%) 5 (8%) 0.02 Sick Sinus Syndrome 1 (8%) 7 (11%) 0.70 Paroxysmal AF 12 (92%) 54 (83%) 0.40 Suspected basal ECG for BrS 13 (100%) 28 (43%) <0.01 Statistical test is considered significant when p value <0.05. Conclusions Up to our knowledge this study is the first one that estimate the prevalence of latent BrS in juvenile lone AF patients. Young patients with lone AF had a high prevalence of latent BrS. Syncope, family history of SCD and family history of BrS are significant indicators of the presence of latent BrS in young patients with lone atrial fibrillation.