Late gadolinium enhancement in Brugada syndrome: A marker for subtle underlying cardiomyopathy?

Background: There is increasing evidence that the Brugada ECG pattern is a marker of subtle structural heart disease.
Objective: The purpose of this study was to characterize patients with Brugada syndrome (BrS) using cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE).
Methods: BrS was diagnosed according to international guidelines. Twenty-six percent of patients with BrS carried SCN5A mutations. CMR data from 78 patients with BrS were compared with 78 healthy controls (44 ± 15 vs 42 ± 14 years; P = .434; and 64% vs 64% male; P = 1).
Results: Right ventricular (RV) ejection fraction was slightly lower (61 ± 8% vs 64 ± 5%; P = .004) and RV end-systolic volume slightly greater (31 ± 10 mL/m ² vs 28 ± 6 mL/m ² ; P = .038) in BrS compared with controls. These values remained within the normal range. LGE was demonstrated in 8% of patients with BrS (left ventricular midwall LGE in 5%) but not in controls (P = .028). In patients with BrS with midwall LGE there were no other features of cardiomyopathy at the time of CMR, but genetic testing and follow-up revealed a desmoplakin mutation in 1 patient and evolution of T-wave inversion throughout all precordial ECG leads in another. Neither patient fulfils diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy.
Conclusion: Some patients with BrS have left ventricular midwall LGE consistent with an underlying cardiomyopathic process. Even cases without LGE show greater RV volumes and reduced RV function. These findings lend further support to the presence of subtle structural abnormalities in BrS. The BrS pattern with LGE may serve as early markers for evolution of a cardiomyopathic phenotype over time. CMR is a potentially useful adjunct investigation in the clinical evaluation of BrS.
(Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)