Reflections on Survival Rates in Patients with Brugada Phenocopy

We read with great interest the article “Survival in Patients with Brugada Phenocopy. Case Series” by Fonseca et al. The authors describe a case series of patients with Brugada Phenocopy (BrP) and report in-hospital survival. We commend the authors for addressing an important topic related to BrP; however, we would like to comment on methodological considerations and propose recommendations that may strengthen interpretation and guide future BrP reports.

BrP refers to clinical conditions that lead to Brugada-ECG pattern (Br-ECGp) without the genetic substrate of Brugada Syndrome (BS) and an underlying condition that justifies the ECG change. The term was first used to describe the Br-ECGp caused by the propofol infusion syndrome; however, after several corrections to the concept, drugs that do block the sodium channels were no longer considered part of the BrP spectrum. BrP represents a diagnostic challenge even for experts. The mean accuracy to identify BrP based only on the 12-lead ECGs was 43±33% among 10 international experts. Therefore, the clinical context is essential to differentiate BrP from BS. Anselm et al. presented a systematic diagnostic criterion () for the diagnosis of BrP. Emphasis was placed on the recognition of the underlying clinical condition and the low pretest probability for BrP, in addition to the resolution of the Br-ECGp immediately after resolving the underlying condition. Based on the limited description provided by Fonseca et al., we cannot exclude the possibility that some cases represented concealed BS unmasked by hyperthermia or other triggers. This misclassification bias could alone skew the observed mortality.

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