Brugada phenocopy in fulminant eosinophilic myocarditis: a case series.

Background: Brugada phenocopy (BrP) is a condition that induces reversible Brugada-like electrocardiographic (ECG) changes in patients without true Brugada syndrome. We present two cases of fulminant eosinophilic myocarditis that showed Type 1 Brugada ECG changes in the early phase of the clinical course.

Case summary: Case 1 was a 76-year-old man who developed fulminant eosinophilic myocarditis with ventricular tachycardia while hospitalized for heart failure. Case 2 was a 60-year-old man who presented with cardiogenic shock and was diagnosed with fulminant eosinophilic myocarditis. Both patients showed a Type 1 Brugada ECG at onset, and their ventricular function was greatly reduced. Regarding mechanical circulatory support, Case 1 was treated with venous-arterial extracorporeal membrane oxygenation and intra-aortic balloon pumping. Case 2 had venous-arterial extracorporeal membrane oxygenation and Impella CP insertion. Steroid therapy was introduced in both cases. In Case 1, the Type 1 Brugada ECG took 7 days to improve. Left ventricular function improved with time but right heart function was poor and right heart enlargement remained. In Case 2, the Type 1 Brugada ECG improved on the second day, and left and right heart function improved over time.

Discussion: We report two cases of fulminant eosinophilic myocarditis with Brugada-like ECG and severe right heart dysfunction. BrP in acute myocarditis may be an indicator of right heart failure and an important ECG marker in determining the indication for mechanical circulatory support and improvement of right heart function.