Terminological clarification of Brugada Phenocopy, Brugada Syndrome, and the Brugada ECG pattern: Re. Early repolarization pattern in patients with provocable Brugada Phenocopy: A marker of additional arrhythmogenic cardiomyopathy

Abstract

We read the recent paper by Dr. Peters [1] with great interest and noted that the term Brugada Phenocopy (BrP) was used in the title; however, the discussion focuses on early repolarization pattern (ERP) in the context of arrhythmogenic right ventricular cardiomyopathy and provocable Brugada ECG pattern with sodium channel blockers. We have been publishing extensively on the subject of BrP [2–9] and would like to suggest a clarification on terminology so as to facilitate future research on BrP and avoid confusion with other forms of ERP. As previously described, Bayes de Luna et al. articulated the ECG criteria for type 1 and type 2 Brugada ECG patterns in the most recent consensus report [10]. In our recent publications [2–9], we have established the diagnostic criteria for BrP and would like to identify salient features that differentiate BrP from true congenital Brugada Syndrome (BrS). First, patients with BrP and BrS both have identical type 1 or type 2 ECG patterns in precordial leads V1–V3. Second, patients with BrP have an identifiable underlying condition that elicits the Brugada ECG pattern and once this underlying condition resolves, the ECG normalizes. Additionally, patients with BrS have a high clinical pretest probability of true congenital BrS, while patients with BrP have a low clinical pretest probability of true congenital BrS suggested by lack of symptoms, medical history, or family history. Most importantly, patients with BrP have a negative provocative challenge with sodium channel blockers such as procainamide, flecainide, or ajmaline while patients with true congenital BrS have a positive provocative challenge. As such, right ventricular outflow tract sodium channel dysfunction in patients with BrS may have a different pathophysiological basis compared to patients with BrP; however, the underlying mechanisms have yet to be elucidated. We thank Dr. Peters for incorporating the relatively new term Brugada Phenocopy into his literature but we would like to emphasize that this term should not be used for cases where the Brugada ECG pattern is provoked by the use of sodium channel blockers [2]. We are developing an international online registry at www.brugadaphenocopy.com and encourage all investigators working on BrP to submit their cases online in order to provide long-term follow-up and insight into the clinical evolution of this emerging phenomenon. The authors of this manuscript certify that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology.