Recurrent myocarditis as a clinical gateway to desmoplakin cardiomyopathy: a case report

Background: Recurrent acute myocarditis is an uncommon clinical scenario that may suggest the presence of an underlying genetic cardiomyopathy. Case summary: A 30-year-old woman presented to the emergency department with recurrent acute myocarditis in 2020 and 2022 and presented to the consult with chest pain in 2023. A syndromic diagnostic workup ruled out infectious, autoimmune, and toxic aetiologies. Cardiac magnetic resonance imaging revealed subepicardial and mid-myocardial oedema and fibrosis, predominantly affecting the left ventricle, which was subsequently confirmed by an endomyocardial biopsy showing chronic inflammation and interstitial fibrosis. Genetic testing ultimately identified a pathogenic partial deletion in the desmoplakin cardiomyopathy DSP gene, establishing the underlying cause. Management included antiarrhythmic therapy, genetic counselling, lifestyle modifications, and the implantation of a cardioverter-defibrillator. Discussion: Desmoplakin cardiomyopathy is a genetic disorder that can mimic recurrent myocarditis through inflammatory 'hot phases'. Recognition of this phenotype is essential in patients with recurrent myocarditis, especially when imaging findings show left-dominant fibrosis and arrhythmic features. Early diagnosis has important implications for treatment, prognosis, and prevention of sudden cardiac death.