A Case of Left-Dominant Arrhythmogenic Cardiomyopathy Presenting with Cardiac Arrest

Arrhythmogenic cardiomyopathy (ACM) is a genetically inherited cardiomyopathy characterised by the fibro-fatty replacement of the myocardium. Patients can present with symptoms of arrhythmia or heart failure; it is a common cause of sudden cardiac arrest and death in young adults. Originally considered as right ventricular arrhythmogenic cardiomyopathy or dysplasia, this terminology has been updated to include left-dominant and biventricular phenotypes. We report a case of a 41-year-old man who presented with an out-of-hospital cardiac arrest due to ventricular arrhythmia as a first presentation. The patient underwent cardiac magnetic resonance imaging, which revealed severe left ventricular (LV) dysfunction with LV fibro-fatty infiltration and a ring-like subepicardial and mid-wall late gadolinium enhancement in the LV. Genetic sequencing identified a pathogenic desmoplakin gene variant. A diagnosis of left-dominant ACM (ALVC) was made based on his presentation, imaging, and genetic findings. Guideline-directed medical therapy with a beta-blocker and an angiotensin-converting enzyme inhibitor was initiated in the first instance. An implantable cardioverter-defibrillator was inserted for secondary prevention. This report highlights the presentation, current diagnostic criteria with a particular focus on ALVC, and the importance of the multimodality approach in the recognition and management of patients with ACM.