Atrial Abnormalities in Brugada Syndrome Evaluation With ECG Imaging

BACKGROUND Patients with Brugada syndrome (BrS) have an increased risk of arrhythmias, including atrial tachyarrhythmias (ATas). OBJECTIVES The purpose of this study was to assess underlying atrial cardiomyopathy in BrS and the effect of ajmaline (AJM) test on the atrium of BrS patients using electrocardiogram imaging (ECGI). METHODS All consecutive patients diagnosed with BrS in a monocentric registry were screened and included if they met the following criteria: 1) BrS diagnosed following current recommendations; and 2) ECGI map performed before and after AJM with a standard protocol. Consecutive patients with no structural heart disease or BrS who had undergone ECGI were included as a control group. Genetic analysis for SCN5A was performed in all BrS patients. Total atrial conduction time (TACT) and local atrial conduction time (LACT) were calculated from atrial ECGI. The primary endpoint was ATas during follow-up. RESULTS Forty-three consecutive BrS patients and 40 control patients were included. Both TACT and LACT were significantly prolonged in BrS patients compared with control patients. Furthermore, TACT and LACT were significantly higher after AJM administration and in BrS patients who were carriers of a pathogenic/likely pathogenic SCN5A variant. After a mean follow-up of 40.9 months, 6 patients experienced a first ATa occurrence (all in the BrS group, 13.9%). TACT was the only independent predictor of ATas with a cutoff of >138.5 ms (sensitivity 0.92 [95% CI: 0.83-0.98], specificity 0.70 [95% CI: 0.59-0.81]). CONCLUSIONS ECGI-calculated TACT and LACT are significantly prolonged in BrS patients compared with control patients, and in BrS patients after AJM. This may be consistent with a concealed atrial cardiomyopathy in BrS. (J Am Coll Cardiol EP 2023;9:2096-2105) (c) 2023 by the American College of Cardiology Foundation.

Automated summary

This study assessed underlying atrial cardiomyopathy in Brugada syndrome (BrS) and the effect of ajmaline test on the atrium of BrS patients using electrocardiogram imaging (ECGI). The study found that total atrial conduction time (TACT) and local atrial conduction time (LACT) were significantly prolonged in BrS patients, particularly after ajmaline administration and in patients with pathogenic SCN5A variants. TACT was identified as an independent predictor of atrial tachyarrhythmias (ATas) in BrS patients.