Brugada Phenocopies: A Review of Mechanisms, Clinical Implications and Prognostic Considerations

Brugada phenocopy (BrP) is a clinical entity characterised by an identical ECG pattern to that of Brugada syndrome, albeit in the absence of congenital sodium channel dysfunction. In BrP, diagnosis is based on the presence of an identifiable underlying trigger that elicits the typical ECG pattern and non-reproducible electrical changes associated with the administration of sodium channel blockers. Although a wide variety of conditions can elicit BrP, the underlying electrophysiological mechanisms leading to the ECG changes are incompletely understood. Experimental models mimicking phenocopy-inducing conditions and integrative evidence of genetic and environmentally modulated mechanisms of sodium channel dysfunction are imperative to gain insights into the mechanisms behind BrP. In this review, we summarise current literature on BrP and describe aetiologies and reproducibility, diagnostic and therapeutic approaches, prognostic implications and emerging evidence on the pathophysiological mechanisms behind the spectrum of phenotypes of sodium channel dysfunction that can help understand the phenomenon of BrP.